diff --git a/swh/web/browse/snapshot_context.py b/swh/web/browse/snapshot_context.py
index df66668c..e619650e 100644
--- a/swh/web/browse/snapshot_context.py
+++ b/swh/web/browse/snapshot_context.py
@@ -1,1464 +1,1464 @@
 # Copyright (C) 2018-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU Affero General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 # Utility module for browsing the archive in a snapshot context.
 
 from collections import defaultdict
 from copy import copy
 from typing import Any, Dict, List, Optional, Tuple
 
 
 from django.core.cache import cache
 from django.shortcuts import render
 from django.template.defaultfilters import filesizeformat
 from django.utils.html import escape
 
 from swh.model.identifiers import (
     swhid,
     snapshot_identifier,
     CONTENT,
     DIRECTORY,
     REVISION,
     RELEASE,
     SNAPSHOT,
 )
 
 from swh.web.browse.utils import (
     get_directory_entries,
     gen_directory_link,
     gen_revision_link,
     gen_revision_url,
     request_content,
     gen_content_link,
     prepare_content_for_display,
     content_display_max_size,
     format_log_entries,
     gen_revision_log_link,
     gen_release_link,
     get_readme_to_display,
     gen_snapshot_link,
 )
 
 from swh.web.common import service, highlightjs
 from swh.web.common.exc import handle_view_exception, NotFoundExc, BadInputExc
 from swh.web.common.identifiers import get_swhids_info
 from swh.web.common.origin_visits import get_origin_visit
 from swh.web.common.typing import (
     OriginInfo,
     SnapshotBranchInfo,
     SnapshotReleaseInfo,
     SnapshotContext,
     ContentMetadata,
     DirectoryMetadata,
     SWHObjectInfo,
 )
 from swh.web.common.utils import (
     reverse,
     gen_path_info,
     format_utc_iso_date,
     swh_object_icons,
 )
 from swh.web.config import get_config
 
 
 _empty_snapshot_id = snapshot_identifier({"branches": {}})
 
 
 def _get_branch(branches, branch_name, snapshot_id):
     """
     Utility function to get a specific branch from a branches list.
     Its purpose is to get the default HEAD branch as some software origin
     (e.g those with svn type) does not have it. In that latter case, check
     if there is a master branch instead and returns it.
     """
     filtered_branches = [b for b in branches if b["name"] == branch_name]
     if filtered_branches:
         return filtered_branches[0]
     elif branch_name == "HEAD":
         filtered_branches = [b for b in branches if b["name"].endswith("master")]
         if filtered_branches:
             return filtered_branches[0]
         elif branches:
             return branches[0]
     else:
         # case where a large branches list has been truncated
         snp = service.lookup_snapshot(
             snapshot_id,
             branches_from=branch_name,
             branches_count=1,
             target_types=["revision", "alias"],
         )
         snp_branch, _ = process_snapshot_branches(snp)
         if snp_branch and snp_branch[0]["name"] == branch_name:
             branches.append(snp_branch[0])
             return snp_branch[0]
 
 
 def _get_release(releases, release_name, snapshot_id):
     """
     Utility function to get a specific release from a releases list.
     Returns None if the release can not be found in the list.
     """
     filtered_releases = [r for r in releases if r["name"] == release_name]
     if filtered_releases:
         return filtered_releases[0]
     else:
         # case where a large branches list has been truncated
         try:
             # git origins have specific branches for releases
             snp = service.lookup_snapshot(
                 snapshot_id,
                 branches_from=f"refs/tags/{release_name}",
                 branches_count=1,
                 target_types=["release"],
             )
         except NotFoundExc:
             snp = service.lookup_snapshot(
                 snapshot_id,
                 branches_from=release_name,
                 branches_count=1,
                 target_types=["release"],
             )
         _, snp_release = process_snapshot_branches(snp)
         if snp_release and snp_release[0]["name"] == release_name:
             releases.append(snp_release[0])
             return snp_release[0]
 
 
 def _branch_not_found(
     branch_type, branch, snapshot_id, snapshot_sizes, origin_info, timestamp, visit_id
 ):
     """
     Utility function to raise an exception when a specified branch/release
     can not be found.
     """
     if branch_type == "branch":
         branch_type = "Branch"
         branch_type_plural = "branches"
         target_type = "revision"
     else:
         branch_type = "Release"
         branch_type_plural = "releases"
         target_type = "release"
 
     if snapshot_id and snapshot_sizes[target_type] == 0:
         msg = "Snapshot with id %s has an empty list" " of %s!" % (
             snapshot_id,
             branch_type_plural,
         )
     elif snapshot_id:
         msg = "%s %s for snapshot with id %s" " not found!" % (
             branch_type,
             branch,
             snapshot_id,
         )
     elif visit_id and snapshot_sizes[target_type] == 0:
         msg = (
             "Origin with url %s"
             " for visit with id %s has an empty list"
             " of %s!" % (origin_info["url"], visit_id, branch_type_plural)
         )
     elif visit_id:
         msg = (
             "%s %s associated to visit with"
             " id %s for origin with url %s"
             " not found!" % (branch_type, branch, visit_id, origin_info["url"])
         )
     elif snapshot_sizes[target_type] == 0:
         msg = (
             "Origin with url %s"
             " for visit with timestamp %s has an empty list"
             " of %s!" % (origin_info["url"], timestamp, branch_type_plural)
         )
     else:
         msg = (
             "%s %s associated to visit with"
             " timestamp %s for origin with "
             "url %s not found!" % (branch_type, branch, timestamp, origin_info["url"])
         )
     raise NotFoundExc(escape(msg))
 
 
 def process_snapshot_branches(
     snapshot: Dict[str, Any]
 ) -> Tuple[List[SnapshotBranchInfo], List[SnapshotReleaseInfo]]:
     """
     Process a dictionary describing snapshot branches: extract those
     targeting revisions and releases, put them in two different lists,
     then sort those lists in lexicographical order of the branches' names.
 
     Args:
         snapshot: A dict describing a snapshot as returned for instance by
             :func:`swh.web.common.service.lookup_snapshot`
 
     Returns:
         A tuple whose first member is the sorted list of branches
         targeting revisions and second member the sorted list of branches
         targeting releases
     """
     snapshot_branches = snapshot["branches"]
     branches: Dict[str, SnapshotBranchInfo] = {}
     branch_aliases: Dict[str, str] = {}
     releases: Dict[str, SnapshotReleaseInfo] = {}
     revision_to_branch = defaultdict(set)
     revision_to_release = defaultdict(set)
     release_to_branch = defaultdict(set)
     for branch_name, target in snapshot_branches.items():
         if not target:
             # FIXME: display branches with an unknown target anyway
             continue
         target_id = target["target"]
         target_type = target["target_type"]
         if target_type == "revision":
             branches[branch_name] = SnapshotBranchInfo(
                 name=branch_name,
                 revision=target_id,
                 date=None,
                 directory=None,
                 message=None,
                 url=None,
             )
             revision_to_branch[target_id].add(branch_name)
         elif target_type == "release":
             release_to_branch[target_id].add(branch_name)
         elif target_type == "alias":
             branch_aliases[branch_name] = target_id
         # FIXME: handle pointers to other object types
 
     def _add_release_info(branch, release):
         releases[branch] = SnapshotReleaseInfo(
             name=release["name"],
             branch_name=branch,
             date=format_utc_iso_date(release["date"]),
             directory=None,
             id=release["id"],
             message=release["message"],
             target_type=release["target_type"],
             target=release["target"],
             url=None,
         )
 
     def _add_branch_info(branch, revision):
         branches[branch] = SnapshotBranchInfo(
             name=branch,
             revision=revision["id"],
             directory=revision["directory"],
             date=format_utc_iso_date(revision["date"]),
             message=revision["message"],
             url=None,
         )
 
     releases_info = service.lookup_release_multiple(release_to_branch.keys())
     for release in releases_info:
         if release is None:
             continue
         branches_to_update = release_to_branch[release["id"]]
         for branch in branches_to_update:
             _add_release_info(branch, release)
         if release["target_type"] == "revision":
             revision_to_release[release["target"]].update(branches_to_update)
 
     revisions = service.lookup_revision_multiple(
         set(revision_to_branch.keys()) | set(revision_to_release.keys())
     )
 
     for revision in revisions:
         if not revision:
             continue
         for branch in revision_to_branch[revision["id"]]:
             _add_branch_info(branch, revision)
         for release_id in revision_to_release[revision["id"]]:
             releases[release_id]["directory"] = revision["directory"]
 
     for branch_alias, branch_target in branch_aliases.items():
         if branch_target in branches:
             branches[branch_alias] = copy(branches[branch_target])
         else:
             snp = service.lookup_snapshot(
                 snapshot["id"], branches_from=branch_target, branches_count=1
             )
             if snp and branch_target in snp["branches"]:
 
                 if snp["branches"][branch_target] is None:
                     continue
 
                 target_type = snp["branches"][branch_target]["target_type"]
                 target = snp["branches"][branch_target]["target"]
                 if target_type == "revision":
                     branches[branch_alias] = snp["branches"][branch_target]
                     revision = service.lookup_revision(target)
                     _add_branch_info(branch_alias, revision)
                 elif target_type == "release":
                     release = service.lookup_release(target)
                     _add_release_info(branch_alias, release)
 
         if branch_alias in branches:
             branches[branch_alias]["name"] = branch_alias
 
     ret_branches = list(sorted(branches.values(), key=lambda b: b["name"]))
     ret_releases = list(sorted(releases.values(), key=lambda b: b["name"]))
 
     return ret_branches, ret_releases
 
 
 def get_snapshot_content(
     snapshot_id: str,
 ) -> Tuple[List[SnapshotBranchInfo], List[SnapshotReleaseInfo]]:
     """Returns the lists of branches and releases
     associated to a swh snapshot.
     That list is put in  cache in order to speedup the navigation
     in the swh-web/browse ui.
 
     .. warning:: At most 1000 branches contained in the snapshot
         will be returned for performance reasons.
 
     Args:
         snapshot_id: hexadecimal representation of the snapshot identifier
 
     Returns:
         A tuple with two members. The first one is a list of dict describing
         the snapshot branches. The second one is a list of dict describing the
         snapshot releases.
 
     Raises:
         NotFoundExc if the snapshot does not exist
     """
     cache_entry_id = "swh_snapshot_%s" % snapshot_id
     cache_entry = cache.get(cache_entry_id)
 
     if cache_entry:
         return cache_entry["branches"], cache_entry["releases"]
 
     branches: List[SnapshotBranchInfo] = []
     releases: List[SnapshotReleaseInfo] = []
 
     snapshot_content_max_size = get_config()["snapshot_content_max_size"]
 
     if snapshot_id:
         snapshot = service.lookup_snapshot(
             snapshot_id, branches_count=snapshot_content_max_size
         )
         branches, releases = process_snapshot_branches(snapshot)
 
     cache.set(cache_entry_id, {"branches": branches, "releases": releases,})
 
     return branches, releases
 
 
 def get_origin_visit_snapshot(
     origin_info: OriginInfo,
     visit_ts: Optional[str] = None,
     visit_id: Optional[int] = None,
     snapshot_id: Optional[str] = None,
 ) -> Tuple[List[SnapshotBranchInfo], List[SnapshotReleaseInfo]]:
     """Returns the lists of branches and releases associated to an origin for
     a given visit.
 
     The visit is expressed by either:
 
         * a snapshot identifier
         * a timestamp, if no visit with that exact timestamp is found,
           the closest one from the provided timestamp will be used.
 
     If no visit parameter is provided, it returns the list of branches
     found for the latest visit.
 
     That list is put in  cache in order to speedup the navigation
     in the swh-web/browse ui.
 
     .. warning:: At most 1000 branches contained in the snapshot
         will be returned for performance reasons.
 
     Args:
         origin_info: a dict filled with origin information
         visit_ts: an ISO 8601 datetime string to parse
         visit_id: visit id for disambiguation in case several visits have
             the same timestamp
         snapshot_id: if provided, visit associated to the snapshot will be processed
 
     Returns:
         A tuple with two members. The first one is a list of dict describing
         the origin branches for the given visit.
         The second one is a list of dict describing the origin releases
         for the given visit.
 
     Raises:
         NotFoundExc if the origin or its visit are not found
     """
 
     visit_info = get_origin_visit(origin_info, visit_ts, visit_id, snapshot_id)
 
     return get_snapshot_content(visit_info["snapshot"])
 
 
 def get_snapshot_context(
     snapshot_id: Optional[str] = None,
     origin_url: Optional[str] = None,
     timestamp: Optional[str] = None,
     visit_id: Optional[int] = None,
     branch_name: Optional[str] = None,
     release_name: Optional[str] = None,
     revision_id: Optional[str] = None,
     path: Optional[str] = None,
     browse_context: str = "directory",
 ) -> SnapshotContext:
     """
     Utility function to compute relevant information when navigating
     the archive in a snapshot context. The snapshot is either
     referenced by its id or it will be retrieved from an origin visit.
 
     Args:
         snapshot_id: hexadecimal representation of a snapshot identifier
         origin_url: an origin_url
         timestamp: a datetime string for retrieving the closest
             visit of the origin
         visit_id: optional visit id for disambiguation in case
             of several visits with the same timestamp
         branch_name: optional branch name set when browsing the snapshot in
             that scope (will default to "HEAD" if not provided)
         release_name: optional release name set when browsing the snapshot in
             that scope
         revision_id: optional revision identifier set when browsing the snapshot in
             that scope
         path: optional path of the object currently browsed in the snapshot
         browse_context: indicates which type of object is currently browsed
 
     Returns:
         A dict filled with snapshot context information.
 
     Raises:
         swh.web.common.exc.NotFoundExc: if no snapshot is found for the visit
             of an origin.
     """
     assert origin_url is not None or snapshot_id is not None
     origin_info = None
     visit_info = None
     url_args = {}
     query_params: Dict[str, Any] = {}
     origin_visits_url = None
 
     if origin_url:
 
         if visit_id is not None:
             query_params["visit_id"] = visit_id
         elif snapshot_id is not None:
             query_params["snapshot"] = snapshot_id
 
         origin_info = service.lookup_origin({"url": origin_url})
 
         visit_info = get_origin_visit(origin_info, timestamp, visit_id, snapshot_id)
         formatted_date = format_utc_iso_date(visit_info["date"])
         visit_info["formatted_date"] = formatted_date
         snapshot_id = visit_info["snapshot"]
 
         if not snapshot_id:
             raise NotFoundExc(
                 "No snapshot associated to the visit of origin "
                 "%s on %s" % (escape(origin_url), formatted_date)
             )
 
         # provided timestamp is not necessarily equals to the one
         # of the retrieved visit, so get the exact one in order
         # to use it in the urls generated below
         if timestamp:
             timestamp = visit_info["date"]
 
         branches, releases = get_origin_visit_snapshot(
             origin_info, timestamp, visit_id, snapshot_id
         )
 
         query_params["origin_url"] = origin_info["url"]
 
         origin_visits_url = reverse(
             "browse-origin-visits", query_params={"origin_url": origin_info["url"]}
         )
 
         if timestamp is not None:
             query_params["timestamp"] = format_utc_iso_date(
                 timestamp, "%Y-%m-%dT%H:%M:%SZ"
             )
 
         visit_url = reverse("browse-origin-directory", query_params=query_params)
         visit_info["url"] = visit_url
 
         branches_url = reverse("browse-origin-branches", query_params=query_params)
 
         releases_url = reverse("browse-origin-releases", query_params=query_params)
     else:
         assert snapshot_id is not None
         branches, releases = get_snapshot_content(snapshot_id)
         url_args = {"snapshot_id": snapshot_id}
         branches_url = reverse("browse-snapshot-branches", url_args=url_args)
 
         releases_url = reverse("browse-snapshot-releases", url_args=url_args)
 
     releases = list(reversed(releases))
 
     snapshot_sizes = service.lookup_snapshot_sizes(snapshot_id)
 
     is_empty = sum(snapshot_sizes.values()) == 0
 
     swh_snp_id = swhid("snapshot", snapshot_id)
 
     if visit_info:
         timestamp = format_utc_iso_date(visit_info["date"])
 
     if origin_info:
         browse_view_name = f"browse-origin-{browse_context}"
     else:
         browse_view_name = f"browse-snapshot-{browse_context}"
 
     release_id = None
     root_directory = None
 
     snapshot_total_size = sum(snapshot_sizes.values())
 
     if path is not None:
         query_params["path"] = path
 
     if snapshot_total_size and revision_id is not None:
         revision = service.lookup_revision(revision_id)
         root_directory = revision["directory"]
         branches.append(
             SnapshotBranchInfo(
                 name=revision_id,
                 revision=revision_id,
                 directory=root_directory,
                 date=revision["date"],
                 message=revision["message"],
                 url=None,
             )
         )
         branch_name = revision_id
         query_params["revision"] = revision_id
     elif snapshot_total_size and release_name:
         release = _get_release(releases, release_name, snapshot_id)
         if release is None:
             _branch_not_found(
                 "release",
                 release_name,
                 snapshot_id,
                 snapshot_sizes,
                 origin_info,
                 timestamp,
                 visit_id,
             )
         else:
             root_directory = release["directory"]
             revision_id = release["target"]
             release_id = release["id"]
             query_params["release"] = release_name
     elif snapshot_total_size:
         if branch_name:
             query_params["branch"] = branch_name
         branch = _get_branch(branches, branch_name or "HEAD", snapshot_id)
         if branch is None:
             _branch_not_found(
                 "branch",
                 branch_name,
                 snapshot_id,
                 snapshot_sizes,
                 origin_info,
                 timestamp,
                 visit_id,
             )
         else:
             branch_name = branch["name"]
             revision_id = branch["revision"]
             root_directory = branch["directory"]
 
     for b in branches:
         branch_query_params = dict(query_params)
         branch_query_params.pop("release", None)
         if b["name"] != b["revision"]:
             branch_query_params.pop("revision", None)
             branch_query_params["branch"] = b["name"]
         b["url"] = reverse(
             browse_view_name, url_args=url_args, query_params=branch_query_params
         )
 
     for r in releases:
         release_query_params = dict(query_params)
         release_query_params.pop("branch", None)
         release_query_params.pop("revision", None)
         release_query_params["release"] = r["name"]
         r["url"] = reverse(
             browse_view_name, url_args=url_args, query_params=release_query_params,
         )
 
     revision_info = None
     if revision_id:
         try:
             revision_info = service.lookup_revision(revision_id)
         except NotFoundExc:
             pass
         else:
             revision_info["date"] = format_utc_iso_date(revision_info["date"])
             revision_info["committer_date"] = format_utc_iso_date(
                 revision_info["committer_date"]
             )
             if revision_info["message"]:
                 message_lines = revision_info["message"].split("\n")
                 revision_info["message_header"] = message_lines[0]
             else:
                 revision_info["message_header"] = ""
 
     snapshot_context = SnapshotContext(
         branch=branch_name,
         branches=branches,
         branches_url=branches_url,
         is_empty=is_empty,
         origin_info=origin_info,
         origin_visits_url=origin_visits_url,
         release=release_name,
         release_id=release_id,
         query_params=query_params,
         releases=releases,
         releases_url=releases_url,
         revision_id=revision_id,
         revision_info=revision_info,
         root_directory=root_directory,
         snapshot_id=snapshot_id,
         snapshot_sizes=snapshot_sizes,
         snapshot_swhid=swh_snp_id,
         url_args=url_args,
         visit_info=visit_info,
     )
 
     if revision_info:
         revision_info["revision_url"] = gen_revision_url(revision_id, snapshot_context)
 
     return snapshot_context
 
 
 def _build_breadcrumbs(snapshot_context: SnapshotContext, path: str):
     origin_info = snapshot_context["origin_info"]
     url_args = snapshot_context["url_args"]
     query_params = dict(snapshot_context["query_params"])
     root_directory = snapshot_context["root_directory"]
 
     path_info = gen_path_info(path)
 
     if origin_info:
         browse_view_name = "browse-origin-directory"
     else:
         browse_view_name = "browse-snapshot-directory"
 
     breadcrumbs = []
     if root_directory:
         query_params.pop("path", None)
         breadcrumbs.append(
             {
                 "name": root_directory[:7],
                 "url": reverse(
                     browse_view_name, url_args=url_args, query_params=query_params
                 ),
             }
         )
     for pi in path_info:
         query_params["path"] = pi["path"]
         breadcrumbs.append(
             {
                 "name": pi["name"],
                 "url": reverse(
                     browse_view_name, url_args=url_args, query_params=query_params
                 ),
             }
         )
     return breadcrumbs
 
 
 def _check_origin_url(snapshot_id, origin_url):
     if snapshot_id is None and origin_url is None:
         raise BadInputExc("An origin URL must be provided as query parameter.")
 
 
 def browse_snapshot_directory(
     request, snapshot_id=None, origin_url=None, timestamp=None, path=None
 ):
     """
     Django view implementation for browsing a directory in a snapshot context.
     """
     try:
 
         _check_origin_url(snapshot_id, origin_url)
 
         snapshot_context = get_snapshot_context(
             snapshot_id=snapshot_id,
             origin_url=origin_url,
             timestamp=timestamp,
             visit_id=request.GET.get("visit_id"),
             path=path,
             browse_context="directory",
             branch_name=request.GET.get("branch"),
             release_name=request.GET.get("release"),
             revision_id=request.GET.get("revision"),
         )
 
         root_directory = snapshot_context["root_directory"]
         sha1_git = root_directory
         if root_directory and path:
             dir_info = service.lookup_directory_with_path(root_directory, path)
             sha1_git = dir_info["target"]
 
         dirs = []
         files = []
         if sha1_git:
             dirs, files = get_directory_entries(sha1_git)
 
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     origin_info = snapshot_context["origin_info"]
     visit_info = snapshot_context["visit_info"]
     url_args = snapshot_context["url_args"]
     query_params = dict(snapshot_context["query_params"])
     revision_id = snapshot_context["revision_id"]
     snapshot_id = snapshot_context["snapshot_id"]
 
     if origin_info:
         browse_view_name = "browse-origin-directory"
     else:
         browse_view_name = "browse-snapshot-directory"
 
     breadcrumbs = _build_breadcrumbs(snapshot_context, path)
 
     path = "" if path is None else (path + "/")
 
     for d in dirs:
         if d["type"] == "rev":
             d["url"] = reverse("browse-revision", url_args={"sha1_git": d["target"]})
         else:
             query_params["path"] = path + d["name"]
             d["url"] = reverse(
                 browse_view_name, url_args=url_args, query_params=query_params
             )
 
     sum_file_sizes = 0
 
     readmes = {}
 
     if origin_info:
         browse_view_name = "browse-origin-content"
     else:
         browse_view_name = "browse-snapshot-content"
 
     for f in files:
         query_params["path"] = path + f["name"]
         f["url"] = reverse(
             browse_view_name, url_args=url_args, query_params=query_params
         )
         if f["length"] is not None:
             sum_file_sizes += f["length"]
             f["length"] = filesizeformat(f["length"])
         if f["name"].lower().startswith("readme"):
             readmes[f["name"]] = f["checksums"]["sha1"]
 
     readme_name, readme_url, readme_html = get_readme_to_display(readmes)
 
     if origin_info:
         browse_view_name = "browse-origin-log"
     else:
         browse_view_name = "browse-snapshot-log"
 
     history_url = None
     if snapshot_id != _empty_snapshot_id:
         query_params.pop("path", None)
         history_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params
         )
 
     nb_files = None
     nb_dirs = None
     dir_path = None
     if root_directory:
         nb_files = len(files)
         nb_dirs = len(dirs)
         sum_file_sizes = filesizeformat(sum_file_sizes)
         dir_path = "/" + path
 
     browse_dir_link = gen_directory_link(sha1_git)
 
     browse_rev_link = gen_revision_link(revision_id)
     browse_snp_link = gen_snapshot_link(snapshot_id)
 
     revision_found = True
     if sha1_git is None and revision_id is not None:
         try:
             service.lookup_revision(revision_id)
         except NotFoundExc:
             revision_found = False
 
     swh_objects = [
         SWHObjectInfo(object_type=DIRECTORY, object_id=sha1_git),
         SWHObjectInfo(object_type=REVISION, object_id=revision_id),
         SWHObjectInfo(object_type=SNAPSHOT, object_id=snapshot_id),
     ]
 
     visit_date = None
     visit_type = None
     if visit_info:
         visit_date = format_utc_iso_date(visit_info["date"])
         visit_type = visit_info["type"]
 
     release_id = snapshot_context["release_id"]
     browse_rel_link = None
     if release_id:
         swh_objects.append(SWHObjectInfo(object_type=RELEASE, object_id=release_id))
         browse_rel_link = gen_release_link(release_id)
 
     dir_metadata = DirectoryMetadata(
         object_type=DIRECTORY,
         object_id=sha1_git,
         directory=sha1_git,
         directory_url=browse_dir_link,
         nb_files=nb_files,
         nb_dirs=nb_dirs,
         sum_file_sizes=sum_file_sizes,
         root_directory=root_directory,
         path=dir_path,
         revision=revision_id,
         revision_found=revision_found,
         revision_url=browse_rev_link,
         release=release_id,
         release_url=browse_rel_link,
         snapshot=snapshot_id,
         snapshot_url=browse_snp_link,
         origin_url=origin_url,
         visit_date=visit_date,
         visit_type=visit_type,
     )
 
     vault_cooking = {
         "directory_context": True,
         "directory_id": sha1_git,
         "revision_context": True,
         "revision_id": revision_id,
     }
 
     swhids_info = get_swhids_info(swh_objects, snapshot_context, dir_metadata)
 
     dir_path = "/".join([bc["name"] for bc in breadcrumbs]) + "/"
     context_found = "snapshot: %s" % snapshot_context["snapshot_id"]
     if origin_info:
         context_found = "origin: %s" % origin_info["url"]
     heading = "Directory - %s - %s - %s" % (
         dir_path,
         snapshot_context["branch"],
         context_found,
     )
 
     top_right_link = None
     if not snapshot_context["is_empty"]:
         top_right_link = {
             "url": history_url,
             "icon": swh_object_icons["revisions history"],
             "text": "History",
         }
 
     return render(
         request,
         "browse/directory.html",
         {
             "heading": heading,
             "swh_object_name": "Directory",
             "swh_object_metadata": dir_metadata,
             "dirs": dirs,
             "files": files,
             "breadcrumbs": breadcrumbs if root_directory else [],
             "top_right_link": top_right_link,
             "readme_name": readme_name,
             "readme_url": readme_url,
             "readme_html": readme_html,
             "snapshot_context": snapshot_context,
             "vault_cooking": vault_cooking,
             "show_actions": True,
             "swhids_info": swhids_info,
         },
     )
 
 
 def browse_snapshot_content(
     request,
     snapshot_id=None,
     origin_url=None,
     timestamp=None,
     path=None,
     selected_language=None,
 ):
     """
     Django view implementation for browsing a content in a snapshot context.
     """
     try:
 
         _check_origin_url(snapshot_id, origin_url)
 
         if path is None:
             raise BadInputExc("The path of a content must be given as query parameter.")
 
         snapshot_context = get_snapshot_context(
             snapshot_id=snapshot_id,
             origin_url=origin_url,
             timestamp=timestamp,
             visit_id=request.GET.get("visit_id"),
             path=path,
             browse_context="content",
             branch_name=request.GET.get("branch"),
             release_name=request.GET.get("release"),
             revision_id=request.GET.get("revision"),
         )
 
         root_directory = snapshot_context["root_directory"]
         sha1_git = None
         query_string = None
         content_data = {}
         directory_id = None
         split_path = path.split("/")
         filename = split_path[-1]
         filepath = path[: -len(filename)]
         if root_directory:
             content_info = service.lookup_directory_with_path(root_directory, path)
             sha1_git = content_info["target"]
             query_string = "sha1_git:" + sha1_git
             content_data = request_content(query_string, raise_if_unavailable=False)
 
             if filepath:
                 dir_info = service.lookup_directory_with_path(root_directory, filepath)
                 directory_id = dir_info["target"]
             else:
                 directory_id = root_directory
 
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     revision_id = snapshot_context["revision_id"]
     origin_info = snapshot_context["origin_info"]
     visit_info = snapshot_context["visit_info"]
     snapshot_id = snapshot_context["snapshot_id"]
 
     if content_data.get("raw_data") is not None:
         content_display_data = prepare_content_for_display(
             content_data["raw_data"], content_data["mimetype"], path
         )
         content_data.update(content_display_data)
 
     # Override language with user-selected language
     if selected_language is not None:
         content_data["language"] = selected_language
 
     available_languages = None
 
     if content_data.get("mimetype") is not None and "text/" in content_data["mimetype"]:
         available_languages = highlightjs.get_supported_languages()
 
     breadcrumbs = _build_breadcrumbs(snapshot_context, filepath)
 
     breadcrumbs.append({"name": filename, "url": None})
 
     browse_content_link = gen_content_link(sha1_git)
 
     content_raw_url = None
     if query_string:
         content_raw_url = reverse(
             "browse-content-raw",
             url_args={"query_string": query_string},
             query_params={"filename": filename},
         )
 
     browse_rev_link = gen_revision_link(revision_id)
 
     browse_dir_link = gen_directory_link(directory_id)
 
     content_checksums = content_data.get("checksums", {})
 
     swh_objects = [
         SWHObjectInfo(object_type=CONTENT, object_id=content_checksums.get("sha1_git")),
         SWHObjectInfo(object_type=DIRECTORY, object_id=directory_id),
         SWHObjectInfo(object_type=REVISION, object_id=revision_id),
         SWHObjectInfo(object_type=SNAPSHOT, object_id=snapshot_id),
     ]
 
     visit_date = None
     visit_type = None
     if visit_info:
         visit_date = format_utc_iso_date(visit_info["date"])
         visit_type = visit_info["type"]
 
     release_id = snapshot_context["release_id"]
     browse_rel_link = None
     if release_id:
         swh_objects.append(SWHObjectInfo(object_type=RELEASE, object_id=release_id))
         browse_rel_link = gen_release_link(release_id)
 
     content_metadata = ContentMetadata(
         object_type=CONTENT,
         object_id=content_checksums.get("sha1_git"),
         sha1=content_checksums.get("sha1"),
         sha1_git=content_checksums.get("sha1_git"),
         sha256=content_checksums.get("sha256"),
         blake2s256=content_checksums.get("blake2s256"),
         content_url=browse_content_link,
         mimetype=content_data.get("mimetype"),
         encoding=content_data.get("encoding"),
         size=filesizeformat(content_data.get("length", 0)),
         language=content_data.get("language"),
         licenses=content_data.get("licenses"),
         root_directory=root_directory,
         path=f"/{filepath}",
         filename=filename,
         directory=directory_id,
         directory_url=browse_dir_link,
         revision=revision_id,
         revision_url=browse_rev_link,
         release=release_id,
         release_url=browse_rel_link,
         snapshot=snapshot_id,
         snapshot_url=gen_snapshot_link(snapshot_id),
         origin_url=origin_url,
         visit_date=visit_date,
         visit_type=visit_type,
     )
 
     swhids_info = get_swhids_info(swh_objects, snapshot_context, content_metadata)
 
     content_path = "/".join([bc["name"] for bc in breadcrumbs])
     context_found = "snapshot: %s" % snapshot_context["snapshot_id"]
     if origin_info:
         context_found = "origin: %s" % origin_info["url"]
     heading = "Content - %s - %s - %s" % (
         content_path,
         snapshot_context["branch"],
         context_found,
     )
 
     top_right_link = None
     if not snapshot_context["is_empty"]:
         top_right_link = {
             "url": content_raw_url,
             "icon": swh_object_icons["content"],
             "text": "Raw File",
         }
 
     return render(
         request,
         "browse/content.html",
         {
             "heading": heading,
             "swh_object_name": "Content",
             "swh_object_metadata": content_metadata,
             "content": content_data.get("content_data"),
             "content_size": content_data.get("length"),
             "max_content_size": content_display_max_size,
             "filename": filename,
             "encoding": content_data.get("encoding"),
             "mimetype": content_data.get("mimetype"),
             "language": content_data.get("language"),
             "available_languages": available_languages,
             "breadcrumbs": breadcrumbs if root_directory else [],
             "top_right_link": top_right_link,
             "snapshot_context": snapshot_context,
             "vault_cooking": None,
             "show_actions": True,
             "swhids_info": swhids_info,
             "error_code": content_data.get("error_code"),
             "error_message": content_data.get("error_message"),
             "error_description": content_data.get("error_description"),
         },
         status=content_data.get("error_code", 200),
     )
 
 
 PER_PAGE = 100
 
 
 def browse_snapshot_log(request, snapshot_id=None, origin_url=None, timestamp=None):
     """
     Django view implementation for browsing a revision history in a
     snapshot context.
     """
     try:
 
         _check_origin_url(snapshot_id, origin_url)
 
         snapshot_context = get_snapshot_context(
             snapshot_id=snapshot_id,
             origin_url=origin_url,
             timestamp=timestamp,
             visit_id=request.GET.get("visit_id"),
             browse_context="log",
             branch_name=request.GET.get("branch"),
             release_name=request.GET.get("release"),
             revision_id=request.GET.get("revision"),
         )
 
         revision_id = snapshot_context["revision_id"]
 
         per_page = int(request.GET.get("per_page", PER_PAGE))
         offset = int(request.GET.get("offset", 0))
         revs_ordering = request.GET.get("revs_ordering", "committer_date")
         session_key = "rev_%s_log_ordering_%s" % (revision_id, revs_ordering)
         rev_log_session = request.session.get(session_key, None)
         rev_log = []
         revs_walker_state = None
         if rev_log_session:
             rev_log = rev_log_session["rev_log"]
             revs_walker_state = rev_log_session["revs_walker_state"]
 
         if len(rev_log) < offset + per_page:
             revs_walker = service.get_revisions_walker(
                 revs_ordering,
                 revision_id,
                 max_revs=offset + per_page + 1,
                 state=revs_walker_state,
             )
             rev_log += [rev["id"] for rev in revs_walker]
             revs_walker_state = revs_walker.export_state()
 
         revs = rev_log[offset : offset + per_page]
         revision_log = service.lookup_revision_multiple(revs)
 
         request.session[session_key] = {
             "rev_log": rev_log,
             "revs_walker_state": revs_walker_state,
         }
 
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     origin_info = snapshot_context["origin_info"]
     visit_info = snapshot_context["visit_info"]
     url_args = snapshot_context["url_args"]
     query_params = snapshot_context["query_params"]
     snapshot_id = snapshot_context["snapshot_id"]
 
     query_params["per_page"] = per_page
     revs_ordering = request.GET.get("revs_ordering", "")
-    query_params["revs_ordering"] = revs_ordering
+    query_params["revs_ordering"] = revs_ordering or None
 
     if origin_info:
         browse_view_name = "browse-origin-log"
     else:
         browse_view_name = "browse-snapshot-log"
 
     prev_log_url = None
     if len(rev_log) > offset + per_page:
         query_params["offset"] = offset + per_page
         prev_log_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params
         )
 
     next_log_url = None
     if offset != 0:
         query_params["offset"] = offset - per_page
         next_log_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params
         )
 
     revision_log_data = format_log_entries(revision_log, per_page, snapshot_context)
 
     browse_rev_link = gen_revision_link(revision_id)
 
     browse_log_link = gen_revision_log_link(revision_id)
 
     browse_snp_link = gen_snapshot_link(snapshot_id)
 
     revision_metadata = {
         "context-independent revision": browse_rev_link,
         "context-independent revision history": browse_log_link,
         "context-independent snapshot": browse_snp_link,
         "snapshot": snapshot_id,
     }
 
     if origin_info:
         revision_metadata["origin url"] = origin_info["url"]
         revision_metadata["origin visit date"] = format_utc_iso_date(visit_info["date"])
         revision_metadata["origin visit type"] = visit_info["type"]
 
     swh_objects = [
         SWHObjectInfo(object_type=REVISION, object_id=revision_id),
         SWHObjectInfo(object_type=SNAPSHOT, object_id=snapshot_id),
     ]
 
     release_id = snapshot_context["release_id"]
     if release_id:
         swh_objects.append(SWHObjectInfo(object_type=RELEASE, object_id=release_id))
         browse_rel_link = gen_release_link(release_id)
         revision_metadata["release"] = release_id
         revision_metadata["context-independent release"] = browse_rel_link
 
     swhids_info = get_swhids_info(swh_objects, snapshot_context)
 
     context_found = "snapshot: %s" % snapshot_context["snapshot_id"]
     if origin_info:
         context_found = "origin: %s" % origin_info["url"]
     heading = "Revision history - %s - %s" % (snapshot_context["branch"], context_found)
 
     return render(
         request,
         "browse/revision-log.html",
         {
             "heading": heading,
             "swh_object_name": "Revisions history",
             "swh_object_metadata": revision_metadata,
             "revision_log": revision_log_data,
             "revs_ordering": revs_ordering,
             "next_log_url": next_log_url,
             "prev_log_url": prev_log_url,
             "breadcrumbs": None,
             "top_right_link": None,
             "snapshot_context": snapshot_context,
             "vault_cooking": None,
             "show_actions": True,
             "swhids_info": swhids_info,
         },
     )
 
 
 def browse_snapshot_branches(
     request, snapshot_id=None, origin_url=None, timestamp=None
 ):
     """
     Django view implementation for browsing a list of branches in a snapshot
     context.
     """
     try:
 
         _check_origin_url(snapshot_id, origin_url)
 
         snapshot_context = get_snapshot_context(
             snapshot_id=snapshot_id,
             origin_url=origin_url,
             timestamp=timestamp,
             visit_id=request.GET.get("visit_id"),
         )
 
         branches_bc = request.GET.get("branches_breadcrumbs", "")
         branches_bc = branches_bc.split(",") if branches_bc else []
         branches_from = branches_bc[-1] if branches_bc else ""
 
         origin_info = snapshot_context["origin_info"]
         url_args = snapshot_context["url_args"]
         query_params = snapshot_context["query_params"]
 
         if origin_info:
             browse_view_name = "browse-origin-directory"
         else:
             browse_view_name = "browse-snapshot-directory"
 
         snapshot = service.lookup_snapshot(
             snapshot_context["snapshot_id"],
             branches_from,
             PER_PAGE + 1,
             target_types=["revision", "alias"],
         )
 
         displayed_branches, _ = process_snapshot_branches(snapshot)
 
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     for branch in displayed_branches:
         rev_query_params = {}
         if origin_info:
             rev_query_params["origin_url"] = origin_info["url"]
 
         revision_url = reverse(
             "browse-revision",
             url_args={"sha1_git": branch["revision"]},
             query_params=query_params,
         )
 
         query_params["branch"] = branch["name"]
         directory_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params
         )
         del query_params["branch"]
         branch["revision_url"] = revision_url
         branch["directory_url"] = directory_url
 
     if origin_info:
         browse_view_name = "browse-origin-branches"
     else:
         browse_view_name = "browse-snapshot-branches"
 
     prev_branches_url = None
     next_branches_url = None
 
     if branches_bc:
         query_params_prev = dict(query_params)
 
         query_params_prev["branches_breadcrumbs"] = ",".join(branches_bc[:-1])
         prev_branches_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params_prev
         )
     elif branches_from:
         prev_branches_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params
         )
 
     if snapshot["next_branch"] is not None:
         query_params_next = dict(query_params)
         next_branch = displayed_branches[-1]["name"]
         del displayed_branches[-1]
         branches_bc.append(next_branch)
         query_params_next["branches_breadcrumbs"] = ",".join(branches_bc)
         next_branches_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params_next
         )
 
     heading = "Branches - "
     if origin_info:
         heading += "origin: %s" % origin_info["url"]
     else:
         heading += "snapshot: %s" % snapshot_id
 
     return render(
         request,
         "browse/branches.html",
         {
             "heading": heading,
             "swh_object_name": "Branches",
             "swh_object_metadata": {},
             "top_right_link": None,
             "displayed_branches": displayed_branches,
             "prev_branches_url": prev_branches_url,
             "next_branches_url": next_branches_url,
             "snapshot_context": snapshot_context,
         },
     )
 
 
 def browse_snapshot_releases(
     request, snapshot_id=None, origin_url=None, timestamp=None
 ):
     """
     Django view implementation for browsing a list of releases in a snapshot
     context.
     """
     try:
 
         _check_origin_url(snapshot_id, origin_url)
 
         snapshot_context = get_snapshot_context(
             snapshot_id=snapshot_id,
             origin_url=origin_url,
             timestamp=timestamp,
             visit_id=request.GET.get("visit_id"),
         )
 
         rel_bc = request.GET.get("releases_breadcrumbs", "")
         rel_bc = rel_bc.split(",") if rel_bc else []
         rel_from = rel_bc[-1] if rel_bc else ""
 
         origin_info = snapshot_context["origin_info"]
         url_args = snapshot_context["url_args"]
         query_params = snapshot_context["query_params"]
 
         snapshot = service.lookup_snapshot(
             snapshot_context["snapshot_id"],
             rel_from,
             PER_PAGE + 1,
             target_types=["release", "alias"],
         )
 
         _, displayed_releases = process_snapshot_branches(snapshot)
 
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     for release in displayed_releases:
         query_params_tgt = {"snapshot": snapshot_id}
         if origin_info:
             query_params_tgt["origin_url"] = origin_info["url"]
 
         release_url = reverse(
             "browse-release",
             url_args={"sha1_git": release["id"]},
             query_params=query_params_tgt,
         )
 
         target_url = ""
         if release["target_type"] == "revision":
             target_url = reverse(
                 "browse-revision",
                 url_args={"sha1_git": release["target"]},
                 query_params=query_params_tgt,
             )
         elif release["target_type"] == "directory":
             target_url = reverse(
                 "browse-directory",
                 url_args={"sha1_git": release["target"]},
                 query_params=query_params_tgt,
             )
         elif release["target_type"] == "content":
             target_url = reverse(
                 "browse-content",
                 url_args={"query_string": release["target"]},
                 query_params=query_params_tgt,
             )
         elif release["target_type"] == "release":
             target_url = reverse(
                 "browse-release",
                 url_args={"sha1_git": release["target"]},
                 query_params=query_params_tgt,
             )
 
         release["release_url"] = release_url
         release["target_url"] = target_url
 
     if origin_info:
         browse_view_name = "browse-origin-releases"
     else:
         browse_view_name = "browse-snapshot-releases"
 
     prev_releases_url = None
     next_releases_url = None
 
     if rel_bc:
         query_params_prev = dict(query_params)
 
         query_params_prev["releases_breadcrumbs"] = ",".join(rel_bc[:-1])
         prev_releases_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params_prev
         )
     elif rel_from:
         prev_releases_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params
         )
 
     if snapshot["next_branch"] is not None:
         query_params_next = dict(query_params)
         next_rel = displayed_releases[-1]["branch_name"]
         del displayed_releases[-1]
         rel_bc.append(next_rel)
         query_params_next["releases_breadcrumbs"] = ",".join(rel_bc)
         next_releases_url = reverse(
             browse_view_name, url_args=url_args, query_params=query_params_next
         )
 
     heading = "Releases - "
     if origin_info:
         heading += "origin: %s" % origin_info["url"]
     else:
         heading += "snapshot: %s" % snapshot_id
 
     return render(
         request,
         "browse/releases.html",
         {
             "heading": heading,
             "top_panel_visible": False,
             "top_panel_collapsible": False,
             "swh_object_name": "Releases",
             "swh_object_metadata": {},
             "top_right_link": None,
             "displayed_releases": displayed_releases,
             "prev_releases_url": prev_releases_url,
             "next_releases_url": next_releases_url,
             "snapshot_context": snapshot_context,
             "vault_cooking": None,
             "show_actions": False,
         },
     )
diff --git a/swh/web/browse/views/revision.py b/swh/web/browse/views/revision.py
index 597b81a9..fd0bf5ab 100644
--- a/swh/web/browse/views/revision.py
+++ b/swh/web/browse/views/revision.py
@@ -1,606 +1,606 @@
 # Copyright (C) 2017-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU Affero General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import hashlib
 import json
 import textwrap
 
 from django.http import HttpResponse
 from django.shortcuts import render
 from django.template.defaultfilters import filesizeformat
 from django.utils.safestring import mark_safe
 
 from swh.model.identifiers import (
     swhid,
     CONTENT,
     DIRECTORY,
     REVISION,
     SNAPSHOT,
 )
 from swh.web.browse.browseurls import browse_route
 from swh.web.browse.snapshot_context import get_snapshot_context
 from swh.web.browse.utils import (
     gen_link,
     gen_revision_link,
     gen_revision_url,
     get_revision_log_url,
     get_directory_entries,
     gen_directory_link,
     request_content,
     prepare_content_for_display,
     content_display_max_size,
     gen_snapshot_link,
     get_readme_to_display,
     format_log_entries,
     gen_person_mail_link,
 )
 from swh.web.common import service
 from swh.web.common.exc import NotFoundExc, handle_view_exception
 from swh.web.common.identifiers import get_swhids_info
 from swh.web.common.typing import RevisionMetadata, SWHObjectInfo
 from swh.web.common.utils import (
     reverse,
     format_utc_iso_date,
     gen_path_info,
     swh_object_icons,
 )
 
 
 def _gen_content_url(revision, query_string, path, snapshot_context):
     if snapshot_context:
         query_params = snapshot_context["query_params"]
         query_params["path"] = path
         query_params["revision"] = revision["id"]
         content_url = reverse("browse-origin-content", query_params=query_params)
     else:
         content_path = "%s/%s" % (revision["directory"], path)
         content_url = reverse(
             "browse-content",
             url_args={"query_string": query_string},
             query_params={"path": content_path},
         )
     return content_url
 
 
 def _gen_diff_link(idx, diff_anchor, link_text):
     if idx < _max_displayed_file_diffs:
         return gen_link(diff_anchor, link_text)
     else:
         return link_text
 
 
 # TODO: put in conf
 _max_displayed_file_diffs = 1000
 
 
 def _gen_revision_changes_list(revision, changes, snapshot_context):
     """
     Returns a HTML string describing the file changes
     introduced in a revision.
     As this string will be displayed in the browse revision view,
     links to adequate file diffs are also generated.
 
     Args:
         revision (str): hexadecimal representation of a revision identifier
         changes (list): list of file changes in the revision
         snapshot_context (dict): optional origin context used to reverse
             the content urls
 
     Returns:
         A string to insert in a revision HTML view.
 
     """
     changes_msg = []
     for i, change in enumerate(changes):
         hasher = hashlib.sha1()
         from_query_string = ""
         to_query_string = ""
         diff_id = "diff-"
         if change["from"]:
             from_query_string = "sha1_git:" + change["from"]["target"]
             diff_id += change["from"]["target"] + "-" + change["from_path"]
         diff_id += "-"
         if change["to"]:
             to_query_string = "sha1_git:" + change["to"]["target"]
             diff_id += change["to"]["target"] + change["to_path"]
         change["path"] = change["to_path"] or change["from_path"]
         url_args = {
             "from_query_string": from_query_string,
             "to_query_string": to_query_string,
         }
         query_params = {"path": change["path"]}
         change["diff_url"] = reverse(
             "diff-contents", url_args=url_args, query_params=query_params
         )
 
         hasher.update(diff_id.encode("utf-8"))
         diff_id = hasher.hexdigest()
         change["id"] = diff_id
         diff_link = "#diff_" + diff_id
 
         if change["type"] == "modify":
             change["content_url"] = _gen_content_url(
                 revision, to_query_string, change["to_path"], snapshot_context
             )
             changes_msg.append(
                 "modified:  %s" % _gen_diff_link(i, diff_link, change["to_path"])
             )
         elif change["type"] == "insert":
             change["content_url"] = _gen_content_url(
                 revision, to_query_string, change["to_path"], snapshot_context
             )
             changes_msg.append(
                 "new file:  %s" % _gen_diff_link(i, diff_link, change["to_path"])
             )
         elif change["type"] == "delete":
             parent = service.lookup_revision(revision["parents"][0])
             change["content_url"] = _gen_content_url(
                 parent, from_query_string, change["from_path"], snapshot_context
             )
             changes_msg.append(
                 "deleted:   %s" % _gen_diff_link(i, diff_link, change["from_path"])
             )
         elif change["type"] == "rename":
             change["content_url"] = _gen_content_url(
                 revision, to_query_string, change["to_path"], snapshot_context
             )
             link_text = change["from_path"] + " &rarr; " + change["to_path"]
             changes_msg.append(
                 "renamed:   %s" % _gen_diff_link(i, diff_link, link_text)
             )
     if not changes:
         changes_msg.append("No changes")
     return mark_safe("\n".join(changes_msg))
 
 
 @browse_route(
     r"revision/(?P<sha1_git>[0-9a-f]+)/diff/",
     view_name="diff-revision",
     checksum_args=["sha1_git"],
 )
 def _revision_diff(request, sha1_git):
     """
     Browse internal endpoint to compute revision diff
     """
     try:
         revision = service.lookup_revision(sha1_git)
         snapshot_context = None
         origin_url = request.GET.get("origin_url", None)
         if not origin_url:
             origin_url = request.GET.get("origin", None)
         timestamp = request.GET.get("timestamp", None)
         visit_id = request.GET.get("visit_id", None)
         if origin_url:
             snapshot_context = get_snapshot_context(
                 origin_url=origin_url, timestamp=timestamp, visit_id=visit_id
             )
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     changes = service.diff_revision(sha1_git)
     changes_msg = _gen_revision_changes_list(revision, changes, snapshot_context)
 
     diff_data = {
         "total_nb_changes": len(changes),
         "changes": changes[:_max_displayed_file_diffs],
         "changes_msg": changes_msg,
     }
     diff_data_json = json.dumps(diff_data, separators=(",", ": "))
     return HttpResponse(diff_data_json, content_type="application/json")
 
 
 NB_LOG_ENTRIES = 100
 
 
 @browse_route(
     r"revision/(?P<sha1_git>[0-9a-f]+)/log/",
     view_name="browse-revision-log",
     checksum_args=["sha1_git"],
 )
 def revision_log_browse(request, sha1_git):
     """
     Django view that produces an HTML display of the history
     log for a revision identified by its id.
 
     The url that points to it is :http:get:`/browse/revision/(sha1_git)/log/`
     """
     try:
         origin_url = request.GET.get("origin_url")
         snapshot_id = request.GET.get("snapshot")
         snapshot_context = None
         if origin_url or snapshot_id:
             snapshot_context = get_snapshot_context(
                 snapshot_id=snapshot_id,
                 origin_url=origin_url,
                 timestamp=request.GET.get("timestamp"),
                 visit_id=request.GET.get("visit_id"),
                 branch_name=request.GET.get("branch"),
                 release_name=request.GET.get("release"),
                 revision_id=sha1_git,
             )
         per_page = int(request.GET.get("per_page", NB_LOG_ENTRIES))
         offset = int(request.GET.get("offset", 0))
         revs_ordering = request.GET.get("revs_ordering", "committer_date")
         session_key = "rev_%s_log_ordering_%s" % (sha1_git, revs_ordering)
         rev_log_session = request.session.get(session_key, None)
         rev_log = []
         revs_walker_state = None
         if rev_log_session:
             rev_log = rev_log_session["rev_log"]
             revs_walker_state = rev_log_session["revs_walker_state"]
 
         if len(rev_log) < offset + per_page:
             revs_walker = service.get_revisions_walker(
                 revs_ordering,
                 sha1_git,
                 max_revs=offset + per_page + 1,
                 state=revs_walker_state,
             )
 
             rev_log += [rev["id"] for rev in revs_walker]
             revs_walker_state = revs_walker.export_state()
 
         revs = rev_log[offset : offset + per_page]
         revision_log = service.lookup_revision_multiple(revs)
 
         request.session[session_key] = {
             "rev_log": rev_log,
             "revs_walker_state": revs_walker_state,
         }
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     revs_ordering = request.GET.get("revs_ordering", "")
 
     prev_log_url = None
     if len(rev_log) > offset + per_page:
         prev_log_url = reverse(
             "browse-revision-log",
             url_args={"sha1_git": sha1_git},
             query_params={
                 "per_page": per_page,
                 "offset": offset + per_page,
-                "revs_ordering": revs_ordering,
+                "revs_ordering": revs_ordering or None,
             },
         )
 
     next_log_url = None
     if offset != 0:
         next_log_url = reverse(
             "browse-revision-log",
             url_args={"sha1_git": sha1_git},
             query_params={
                 "per_page": per_page,
                 "offset": offset - per_page,
-                "revs_ordering": revs_ordering,
+                "revs_ordering": revs_ordering or None,
             },
         )
 
     revision_log_data = format_log_entries(revision_log, per_page)
 
     swh_rev_id = swhid("revision", sha1_git)
 
     return render(
         request,
         "browse/revision-log.html",
         {
             "heading": "Revision history",
             "swh_object_id": swh_rev_id,
             "swh_object_name": "Revisions history",
             "swh_object_metadata": None,
             "revision_log": revision_log_data,
             "revs_ordering": revs_ordering,
             "next_log_url": next_log_url,
             "prev_log_url": prev_log_url,
             "breadcrumbs": None,
             "top_right_link": None,
             "snapshot_context": snapshot_context,
             "vault_cooking": None,
             "show_actions": True,
             "swhids_info": None,
         },
     )
 
 
 @browse_route(
     r"revision/(?P<sha1_git>[0-9a-f]+)/",
     view_name="browse-revision",
     checksum_args=["sha1_git"],
 )
 def revision_browse(request, sha1_git):
     """
     Django view that produces an HTML display of a revision
     identified by its id.
 
     The url that points to it is :http:get:`/browse/revision/(sha1_git)/`.
     """
     try:
         revision = service.lookup_revision(sha1_git)
         origin_info = None
         snapshot_context = None
         origin_url = request.GET.get("origin_url")
         if not origin_url:
             origin_url = request.GET.get("origin")
         timestamp = request.GET.get("timestamp")
         visit_id = request.GET.get("visit_id")
         snapshot_id = request.GET.get("snapshot_id")
         if not snapshot_id:
             snapshot_id = request.GET.get("snapshot")
         path = request.GET.get("path")
         dir_id = None
         dirs, files = None, None
         content_data = {}
         if origin_url:
             try:
                 snapshot_context = get_snapshot_context(
                     snapshot_id=snapshot_id,
                     origin_url=origin_url,
                     timestamp=timestamp,
                     visit_id=visit_id,
                     branch_name=request.GET.get("branch"),
                     release_name=request.GET.get("release"),
                     revision_id=sha1_git,
                 )
             except NotFoundExc as e:
                 raw_rev_url = reverse(
                     "browse-revision", url_args={"sha1_git": sha1_git}
                 )
                 error_message = (
                     "The Software Heritage archive has a revision "
                     "with the hash you provided but the origin "
                     "mentioned in your request appears broken: %s. "
                     "Please check the URL and try again.\n\n"
                     "Nevertheless, you can still browse the revision "
                     "without origin information: %s"
                     % (gen_link(origin_url), gen_link(raw_rev_url))
                 )
                 if str(e).startswith("Origin"):
                     raise NotFoundExc(error_message)
                 else:
                     raise e
             origin_info = snapshot_context["origin_info"]
             snapshot_id = snapshot_context["snapshot_id"]
         elif snapshot_id:
             snapshot_context = get_snapshot_context(snapshot_id)
 
         if path:
             file_info = service.lookup_directory_with_path(revision["directory"], path)
             if file_info["type"] == "dir":
                 dir_id = file_info["target"]
             else:
                 query_string = "sha1_git:" + file_info["target"]
                 content_data = request_content(query_string, raise_if_unavailable=False)
         else:
             dir_id = revision["directory"]
 
         if dir_id:
             path = "" if path is None else (path + "/")
             dirs, files = get_directory_entries(dir_id)
     except Exception as exc:
         return handle_view_exception(request, exc)
 
     revision_metadata = RevisionMetadata(
         object_type=REVISION,
         object_id=sha1_git,
         revision=sha1_git,
         revision_url=gen_revision_link(sha1_git),
         author=revision["author"]["fullname"] if revision["author"] else "None",
         author_url=gen_person_mail_link(revision["author"])
         if revision["author"]
         else "None",
         committer=revision["committer"]["fullname"]
         if revision["committer"]
         else "None",
         committer_url=gen_person_mail_link(revision["committer"])
         if revision["committer"]
         else "None",
         committer_date=format_utc_iso_date(revision["committer_date"]),
         date=format_utc_iso_date(revision["date"]),
         directory=revision["directory"],
         directory_url=gen_directory_link(revision["directory"]),
         merge=revision["merge"],
         metadata=json.dumps(
             revision["metadata"], sort_keys=True, indent=4, separators=(",", ": ")
         ),
         parents=revision["parents"],
         synthetic=revision["synthetic"],
         type=revision["type"],
         snapshot=snapshot_id,
         snapshot_url=gen_snapshot_link(snapshot_id) if snapshot_id else None,
         origin_url=origin_url,
     )
 
     message_lines = ["None"]
     if revision["message"]:
         message_lines = revision["message"].split("\n")
 
     parents = []
     for p in revision["parents"]:
         parent_url = gen_revision_url(p, snapshot_context)
         parents.append({"id": p, "url": parent_url})
 
     path_info = gen_path_info(path)
 
     query_params = snapshot_context["query_params"] if snapshot_context else {}
 
     breadcrumbs = []
     breadcrumbs.append(
         {
             "name": revision["directory"][:7],
             "url": reverse(
                 "browse-revision",
                 url_args={"sha1_git": sha1_git},
                 query_params=query_params,
             ),
         }
     )
     for pi in path_info:
         query_params["path"] = pi["path"]
         breadcrumbs.append(
             {
                 "name": pi["name"],
                 "url": reverse(
                     "browse-revision",
                     url_args={"sha1_git": sha1_git},
                     query_params=query_params,
                 ),
             }
         )
 
     vault_cooking = {
         "directory_context": False,
         "directory_id": None,
         "revision_context": True,
         "revision_id": sha1_git,
     }
 
     swh_objects = [SWHObjectInfo(object_type=REVISION, object_id=sha1_git)]
 
     content = None
     content_size = None
     filename = None
     mimetype = None
     language = None
     readme_name = None
     readme_url = None
     readme_html = None
     readmes = {}
     error_code = 200
     error_message = ""
     error_description = ""
 
     extra_context = dict(revision_metadata)
     extra_context["path"] = f"/{path}" if path else "/"
 
     if content_data:
         breadcrumbs[-1]["url"] = None
         content_size = content_data["length"]
         mimetype = content_data["mimetype"]
         if content_data["raw_data"]:
             content_display_data = prepare_content_for_display(
                 content_data["raw_data"], content_data["mimetype"], path
             )
             content = content_display_data["content_data"]
             language = content_display_data["language"]
             mimetype = content_display_data["mimetype"]
         if path:
             filename = path_info[-1]["name"]
             query_params["filename"] = filename
             filepath = "/".join(pi["name"] for pi in path_info[:-1])
             extra_context["path"] = f"/{filepath}/" if filepath else "/"
             extra_context["filename"] = filename
 
         top_right_link = {
             "url": reverse(
                 "browse-content-raw",
                 url_args={"query_string": query_string},
                 query_params={"filename": filename},
             ),
             "icon": swh_object_icons["content"],
             "text": "Raw File",
         }
 
         swh_objects.append(
             SWHObjectInfo(object_type=CONTENT, object_id=file_info["target"])
         )
 
         error_code = content_data["error_code"]
         error_message = content_data["error_message"]
         error_description = content_data["error_description"]
     else:
         for d in dirs:
             if d["type"] == "rev":
                 d["url"] = reverse(
                     "browse-revision", url_args={"sha1_git": d["target"]}
                 )
             else:
                 query_params["path"] = path + d["name"]
                 d["url"] = reverse(
                     "browse-revision",
                     url_args={"sha1_git": sha1_git},
                     query_params=query_params,
                 )
         for f in files:
             query_params["path"] = path + f["name"]
             f["url"] = reverse(
                 "browse-revision",
                 url_args={"sha1_git": sha1_git},
                 query_params=query_params,
             )
             if f["length"] is not None:
                 f["length"] = filesizeformat(f["length"])
             if f["name"].lower().startswith("readme"):
                 readmes[f["name"]] = f["checksums"]["sha1"]
 
         readme_name, readme_url, readme_html = get_readme_to_display(readmes)
 
         top_right_link = {
             "url": get_revision_log_url(sha1_git, snapshot_context),
             "icon": swh_object_icons["revisions history"],
             "text": "History",
         }
 
         vault_cooking["directory_context"] = True
         vault_cooking["directory_id"] = dir_id
 
         swh_objects.append(SWHObjectInfo(object_type=DIRECTORY, object_id=dir_id))
 
     query_params.pop("path", None)
 
     diff_revision_url = reverse(
         "diff-revision", url_args={"sha1_git": sha1_git}, query_params=query_params,
     )
 
     if snapshot_id:
         swh_objects.append(SWHObjectInfo(object_type=SNAPSHOT, object_id=snapshot_id))
 
     swhids_info = get_swhids_info(swh_objects, snapshot_context, extra_context)
 
     heading = "Revision - %s - %s" % (
         sha1_git[:7],
         textwrap.shorten(message_lines[0], width=70),
     )
     if snapshot_context:
         context_found = "snapshot: %s" % snapshot_context["snapshot_id"]
         if origin_info:
             context_found = "origin: %s" % origin_info["url"]
         heading += " - %s" % context_found
 
     return render(
         request,
         "browse/revision.html",
         {
             "heading": heading,
             "swh_object_id": swhids_info[0]["swhid"],
             "swh_object_name": "Revision",
             "swh_object_metadata": revision_metadata,
             "message_header": message_lines[0],
             "message_body": "\n".join(message_lines[1:]),
             "parents": parents,
             "snapshot_context": snapshot_context,
             "dirs": dirs,
             "files": files,
             "content": content,
             "content_size": content_size,
             "max_content_size": content_display_max_size,
             "filename": filename,
             "encoding": content_data.get("encoding"),
             "mimetype": mimetype,
             "language": language,
             "readme_name": readme_name,
             "readme_url": readme_url,
             "readme_html": readme_html,
             "breadcrumbs": breadcrumbs,
             "top_right_link": top_right_link,
             "vault_cooking": vault_cooking,
             "diff_revision_url": diff_revision_url,
             "show_actions": True,
             "swhids_info": swhids_info,
             "error_code": error_code,
             "error_message": error_message,
             "error_description": error_description,
         },
         status=error_code,
     )
diff --git a/swh/web/common/utils.py b/swh/web/common/utils.py
index 7d64deb1..56fe1b31 100644
--- a/swh/web/common/utils.py
+++ b/swh/web/common/utils.py
@@ -1,357 +1,357 @@
 # Copyright (C) 2017-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU Affero General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import re
 
 from datetime import datetime, timezone
 from typing import Optional, Dict, Any
 
 import docutils.parsers.rst
 import docutils.utils
 
 from bs4 import BeautifulSoup
 
 from docutils.core import publish_parts
 from docutils.writers.html5_polyglot import Writer, HTMLTranslator
 
 from django.urls import reverse as django_reverse
 from django.http import QueryDict, HttpRequest
 
 from iso8601 import parse_date, ParseError
 
 from prometheus_client.registry import CollectorRegistry
 
 from rest_framework.authentication import SessionAuthentication
 
 from swh.web.common.exc import BadInputExc
 from swh.web.common.typing import QueryParameters
 from swh.web.config import get_config
 
 
 SWH_WEB_METRICS_REGISTRY = CollectorRegistry(auto_describe=True)
 
 swh_object_icons = {
     "branch": "mdi mdi-source-branch",
     "branches": "mdi mdi-source-branch",
     "content": "mdi mdi-file-document",
     "directory": "mdi mdi-folder",
     "origin": "mdi mdi-source-repository",
     "person": "mdi mdi-account",
     "revisions history": "mdi mdi-history",
     "release": "mdi mdi-tag",
     "releases": "mdi mdi-tag",
     "revision": "mdi mdi-rotate-90 mdi-source-commit",
     "snapshot": "mdi mdi-camera",
     "visits": "mdi mdi-calendar-month",
 }
 
 
 def reverse(
     viewname: str,
     url_args: Optional[Dict[str, Any]] = None,
     query_params: Optional[QueryParameters] = None,
     current_app: Optional[str] = None,
     urlconf: Optional[str] = None,
     request: Optional[HttpRequest] = None,
 ) -> str:
     """An override of django reverse function supporting query parameters.
 
     Args:
         viewname: the name of the django view from which to compute a url
         url_args: dictionary of url arguments indexed by their names
         query_params: dictionary of query parameters to append to the
             reversed url
         current_app: the name of the django app tighten to the view
         urlconf: url configuration module
         request: build an absolute URI if provided
 
     Returns:
         str: the url of the requested view with processed arguments and
         query parameters
     """
 
     if url_args:
         url_args = {k: v for k, v in url_args.items() if v is not None}
 
     url = django_reverse(
         viewname, urlconf=urlconf, kwargs=url_args, current_app=current_app
     )
 
     if query_params:
-        query_params = {k: v for k, v in query_params.items() if v}
+        query_params = {k: v for k, v in query_params.items() if v is not None}
 
     if query_params and len(query_params) > 0:
         query_dict = QueryDict("", mutable=True)
         for k in sorted(query_params.keys()):
             query_dict[k] = query_params[k]
         url += "?" + query_dict.urlencode(safe="/;:")
 
     if request is not None:
         url = request.build_absolute_uri(url)
 
     return url
 
 
 def datetime_to_utc(date):
     """Returns datetime in UTC without timezone info
 
     Args:
         date (datetime.datetime): input datetime with timezone info
 
     Returns:
         datetime.datetime: datetime in UTC without timezone info
     """
     if date.tzinfo and date.tzinfo != timezone.utc:
         return date.astimezone(tz=timezone.utc)
     else:
         return date
 
 
 def parse_iso8601_date_to_utc(iso_date: str) -> datetime:
     """Given an ISO 8601 datetime string, parse the result as UTC datetime.
 
     Returns:
         a timezone-aware datetime representing the parsed date
 
     Raises:
         swh.web.common.exc.BadInputExc: provided date does not respect ISO 8601 format
 
     Samples:
         - 2016-01-12
         - 2016-01-12T09:19:12+0100
         - 2007-01-14T20:34:22Z
 
     """
     try:
         date = parse_date(iso_date)
         return datetime_to_utc(date)
     except ParseError as e:
         raise BadInputExc(e)
 
 
 def shorten_path(path):
     """Shorten the given path: for each hash present, only return the first
     8 characters followed by an ellipsis"""
 
     sha256_re = r"([0-9a-f]{8})[0-9a-z]{56}"
     sha1_re = r"([0-9a-f]{8})[0-9a-f]{32}"
 
     ret = re.sub(sha256_re, r"\1...", path)
     return re.sub(sha1_re, r"\1...", ret)
 
 
 def format_utc_iso_date(iso_date, fmt="%d %B %Y, %H:%M UTC"):
     """Turns a string representation of an ISO 8601 datetime string
     to UTC and format it into a more human readable one.
 
     For instance, from the following input
     string: '2017-05-04T13:27:13+02:00' the following one
     is returned: '04 May 2017, 11:27 UTC'.
     Custom format string may also be provided
     as parameter
 
     Args:
         iso_date (str): a string representation of an ISO 8601 date
         fmt (str): optional date formatting string
 
     Returns:
         str: a formatted string representation of the input iso date
     """
     if not iso_date:
         return iso_date
     date = parse_iso8601_date_to_utc(iso_date)
     return date.strftime(fmt)
 
 
 def gen_path_info(path):
     """Function to generate path data navigation for use
     with a breadcrumb in the swh web ui.
 
     For instance, from a path /folder1/folder2/folder3,
     it returns the following list::
 
         [{'name': 'folder1', 'path': 'folder1'},
          {'name': 'folder2', 'path': 'folder1/folder2'},
          {'name': 'folder3', 'path': 'folder1/folder2/folder3'}]
 
     Args:
         path: a filesystem path
 
     Returns:
         list: a list of path data for navigation as illustrated above.
 
     """
     path_info = []
     if path:
         sub_paths = path.strip("/").split("/")
         path_from_root = ""
         for p in sub_paths:
             path_from_root += "/" + p
             path_info.append({"name": p, "path": path_from_root.strip("/")})
     return path_info
 
 
 def parse_rst(text, report_level=2):
     """
     Parse a reStructuredText string with docutils.
 
     Args:
         text (str): string with reStructuredText markups in it
         report_level (int): level of docutils report messages to print
             (1 info 2 warning 3 error 4 severe 5 none)
 
     Returns:
         docutils.nodes.document: a parsed docutils document
     """
     parser = docutils.parsers.rst.Parser()
     components = (docutils.parsers.rst.Parser,)
     settings = docutils.frontend.OptionParser(
         components=components
     ).get_default_values()
     settings.report_level = report_level
     document = docutils.utils.new_document("rst-doc", settings=settings)
     parser.parse(text, document)
     return document
 
 
 def get_client_ip(request):
     """
     Return the client IP address from an incoming HTTP request.
 
     Args:
         request (django.http.HttpRequest): the incoming HTTP request
 
     Returns:
         str: The client IP address
     """
     x_forwarded_for = request.META.get("HTTP_X_FORWARDED_FOR")
     if x_forwarded_for:
         ip = x_forwarded_for.split(",")[0]
     else:
         ip = request.META.get("REMOTE_ADDR")
     return ip
 
 
 browsers_supported_image_mimes = set(
     [
         "image/gif",
         "image/png",
         "image/jpeg",
         "image/bmp",
         "image/webp",
         "image/svg",
         "image/svg+xml",
     ]
 )
 
 
 def context_processor(request):
     """
     Django context processor used to inject variables
     in all swh-web templates.
     """
     config = get_config()
     if (
         hasattr(request, "user")
         and request.user.is_authenticated
         and not hasattr(request.user, "backend")
     ):
         # To avoid django.template.base.VariableDoesNotExist errors
         # when rendering templates when standard Django user is logged in.
         request.user.backend = "django.contrib.auth.backends.ModelBackend"
     return {
         "swh_object_icons": swh_object_icons,
         "available_languages": None,
         "swh_client_config": config["client_config"],
         "oidc_enabled": bool(config["keycloak"]["server_url"]),
         "browsers_supported_image_mimes": browsers_supported_image_mimes,
     }
 
 
 class EnforceCSRFAuthentication(SessionAuthentication):
     """
     Helper class to enforce CSRF validation on a DRF view
     when a user is not authenticated.
     """
 
     def authenticate(self, request):
         user = getattr(request._request, "user", None)
         self.enforce_csrf(request)
         return (user, None)
 
 
 def resolve_branch_alias(
     snapshot: Dict[str, Any], branch: Optional[Dict[str, Any]]
 ) -> Optional[Dict[str, Any]]:
     """
     Resolve branch alias in snapshot content.
 
     Args:
         snapshot: a full snapshot content
         branch: a branch alias contained in the snapshot
     Returns:
         The real snapshot branch that got aliased.
     """
     while branch and branch["target_type"] == "alias":
         if branch["target"] in snapshot["branches"]:
             branch = snapshot["branches"][branch["target"]]
         else:
             from swh.web.common import service
 
             snp = service.lookup_snapshot(
                 snapshot["id"], branches_from=branch["target"], branches_count=1
             )
             if snp and branch["target"] in snp["branches"]:
                 branch = snp["branches"][branch["target"]]
             else:
                 branch = None
     return branch
 
 
 class _NoHeaderHTMLTranslator(HTMLTranslator):
     """
     Docutils translator subclass to customize the generation of HTML
     from reST-formatted docstrings
     """
 
     def __init__(self, document):
         super().__init__(document)
         self.body_prefix = []
         self.body_suffix = []
 
 
 _HTML_WRITER = Writer()
 _HTML_WRITER.translator_class = _NoHeaderHTMLTranslator
 
 
 def rst_to_html(rst: str) -> str:
     """
     Convert reStructuredText document into HTML.
 
     Args:
         rst: A string containing a reStructuredText document
 
     Returns:
         Body content of the produced HTML conversion.
 
     """
     settings = {
         "initial_header_level": 2,
     }
     pp = publish_parts(rst, writer=_HTML_WRITER, settings_overrides=settings)
     return f'<div class="swh-rst">{pp["html_body"]}</div>'
 
 
 def prettify_html(html: str) -> str:
     """
     Prettify an HTML document.
 
     Args:
         html: Input HTML document
 
     Returns:
         The prettified HTML document
     """
     return BeautifulSoup(html, "lxml").prettify()
diff --git a/swh/web/tests/browse/views/test_revision.py b/swh/web/tests/browse/views/test_revision.py
index 7d19561f..2beda6e7 100644
--- a/swh/web/tests/browse/views/test_revision.py
+++ b/swh/web/tests/browse/views/test_revision.py
@@ -1,294 +1,294 @@
 # Copyright (C) 2017-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU Affero General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import random
 
 from django.utils.html import escape
 from hypothesis import given
 
 from swh.model.identifiers import DIRECTORY, REVISION, SNAPSHOT
 from swh.web.common.identifiers import gen_swhid
 from swh.web.common.utils import reverse, format_utc_iso_date, parse_iso8601_date_to_utc
 from swh.web.tests.django_asserts import assert_contains, assert_template_used
 from swh.web.tests.strategies import origin, revision, unknown_revision, new_origin
 
 
 @given(revision())
 def test_revision_browse(client, archive_data, revision):
     _revision_browse_checks(client, archive_data, revision)
 
 
 @given(origin())
 def test_revision_origin_snapshot_browse(client, archive_data, origin):
     snapshot = archive_data.snapshot_get_latest(origin["url"])
     revision = archive_data.snapshot_get_head(snapshot)
 
     _revision_browse_checks(client, archive_data, revision, origin_url=origin["url"])
     _revision_browse_checks(client, archive_data, revision, snapshot=snapshot)
     _revision_browse_checks(
         client, archive_data, revision, origin_url=origin["url"], snapshot=snapshot,
     )
 
     revision = random.choice(archive_data.revision_log(revision))["id"]
     _revision_browse_checks(client, archive_data, revision, origin_url=origin["url"])
 
 
 @given(revision())
 def test_revision_log_browse(client, archive_data, revision):
     per_page = 10
 
     revision_log = archive_data.revision_log(revision)
 
     revision_log_sorted = sorted(
         revision_log,
         key=lambda rev: -parse_iso8601_date_to_utc(rev["committer_date"]).timestamp(),
     )
 
     url = reverse(
         "browse-revision-log",
         url_args={"sha1_git": revision},
         query_params={"per_page": per_page},
     )
 
     resp = client.get(url)
 
     next_page_url = reverse(
         "browse-revision-log",
         url_args={"sha1_git": revision},
-        query_params={"offset": per_page, "per_page": per_page},
+        query_params={"offset": per_page, "per_page": per_page,},
     )
 
     nb_log_entries = per_page
     if len(revision_log_sorted) < per_page:
         nb_log_entries = len(revision_log_sorted)
 
     assert resp.status_code == 200
     assert_template_used(resp, "browse/revision-log.html")
     assert_contains(resp, '<tr class="swh-revision-log-entry', count=nb_log_entries)
     assert_contains(resp, '<a class="page-link">Newer</a>')
 
     if len(revision_log_sorted) > per_page:
         assert_contains(
             resp, '<a class="page-link" href="%s">Older</a>' % escape(next_page_url),
         )
 
     for log in revision_log_sorted[:per_page]:
         revision_url = reverse("browse-revision", url_args={"sha1_git": log["id"]})
         assert_contains(resp, log["id"][:7])
         assert_contains(resp, log["author"]["name"])
         assert_contains(resp, format_utc_iso_date(log["date"]))
         assert_contains(resp, escape(log["message"]))
         assert_contains(resp, format_utc_iso_date(log["committer_date"]))
         assert_contains(resp, revision_url)
 
     if len(revision_log_sorted) <= per_page:
         return
 
     resp = client.get(next_page_url)
 
     prev_page_url = reverse(
         "browse-revision-log",
         url_args={"sha1_git": revision},
-        query_params={"per_page": per_page},
+        query_params={"offset": 0, "per_page": per_page},
     )
     next_page_url = reverse(
         "browse-revision-log",
         url_args={"sha1_git": revision},
         query_params={"offset": 2 * per_page, "per_page": per_page},
     )
 
     nb_log_entries = len(revision_log_sorted) - per_page
     if nb_log_entries > per_page:
         nb_log_entries = per_page
 
     assert resp.status_code == 200
     assert_template_used(resp, "browse/revision-log.html")
     assert_contains(resp, '<tr class="swh-revision-log-entry', count=nb_log_entries)
 
     assert_contains(
         resp, '<a class="page-link" href="%s">Newer</a>' % escape(prev_page_url)
     )
 
     if len(revision_log_sorted) > 2 * per_page:
         assert_contains(
             resp, '<a class="page-link" href="%s">Older</a>' % escape(next_page_url),
         )
 
     if len(revision_log_sorted) <= 2 * per_page:
         return
 
     resp = client.get(next_page_url)
 
     prev_page_url = reverse(
         "browse-revision-log",
         url_args={"sha1_git": revision},
         query_params={"offset": per_page, "per_page": per_page},
     )
     next_page_url = reverse(
         "browse-revision-log",
         url_args={"sha1_git": revision},
         query_params={"offset": 3 * per_page, "per_page": per_page},
     )
 
     nb_log_entries = len(revision_log_sorted) - 2 * per_page
     if nb_log_entries > per_page:
         nb_log_entries = per_page
 
     assert resp.status_code == 200
     assert_template_used(resp, "browse/revision-log.html")
     assert_contains(resp, '<tr class="swh-revision-log-entry', count=nb_log_entries)
     assert_contains(
         resp, '<a class="page-link" href="%s">Newer</a>' % escape(prev_page_url)
     )
 
     if len(revision_log_sorted) > 3 * per_page:
         assert_contains(
             resp, '<a class="page-link" href="%s">Older</a>' % escape(next_page_url),
         )
 
 
 @given(revision(), unknown_revision(), new_origin())
 def test_revision_request_errors(client, revision, unknown_revision, new_origin):
     url = reverse("browse-revision", url_args={"sha1_git": unknown_revision})
     resp = client.get(url)
     assert resp.status_code == 404
     assert_template_used(resp, "error.html")
     assert_contains(
         resp, "Revision with sha1_git %s not found" % unknown_revision, status_code=404
     )
 
     url = reverse(
         "browse-revision",
         url_args={"sha1_git": revision},
         query_params={"origin_url": new_origin.url},
     )
 
     resp = client.get(url)
     assert resp.status_code == 404
     assert_template_used(resp, "error.html")
     assert_contains(
         resp, "the origin mentioned in your request" " appears broken", status_code=404
     )
 
 
 @given(revision())
 def test_revision_uppercase(client, revision):
     url = reverse(
         "browse-revision-uppercase-checksum", url_args={"sha1_git": revision.upper()}
     )
 
     resp = client.get(url)
     assert resp.status_code == 302
 
     redirect_url = reverse("browse-revision", url_args={"sha1_git": revision})
 
     assert resp["location"] == redirect_url
 
 
 def _revision_browse_checks(
     client, archive_data, revision, origin_url=None, snapshot=None
 ):
 
     query_params = {}
     if origin_url:
         query_params["origin_url"] = origin_url
     if snapshot:
         query_params["snapshot"] = snapshot["id"]
 
     url = reverse(
         "browse-revision", url_args={"sha1_git": revision}, query_params=query_params
     )
 
     revision_data = archive_data.revision_get(revision)
 
     author_name = revision_data["author"]["name"]
     committer_name = revision_data["committer"]["name"]
     dir_id = revision_data["directory"]
 
     if origin_url:
         snapshot = archive_data.snapshot_get_latest(origin_url)
         history_url = reverse(
             "browse-origin-log", query_params={"revision": revision, **query_params},
         )
     elif snapshot:
         history_url = reverse(
             "browse-snapshot-log",
             url_args={"snapshot_id": snapshot["id"]},
             query_params={"revision": revision},
         )
     else:
         history_url = reverse("browse-revision-log", url_args={"sha1_git": revision})
 
     resp = client.get(url)
 
     assert resp.status_code == 200
     assert_template_used(resp, "browse/revision.html")
     assert_contains(resp, author_name)
     assert_contains(resp, committer_name)
     assert_contains(resp, history_url)
 
     for parent in revision_data["parents"]:
         parent_url = reverse(
             "browse-revision", url_args={"sha1_git": parent}, query_params=query_params
         )
         assert_contains(resp, '<a href="%s">%s</a>' % (escape(parent_url), parent[:7]))
 
     author_date = revision_data["date"]
     committer_date = revision_data["committer_date"]
 
     message_lines = revision_data["message"].split("\n")
 
     assert_contains(resp, format_utc_iso_date(author_date))
     assert_contains(resp, format_utc_iso_date(committer_date))
     assert_contains(resp, escape(message_lines[0]))
     assert_contains(resp, escape("\n".join(message_lines[1:])))
 
     assert_contains(resp, "vault-cook-directory")
     assert_contains(resp, "vault-cook-revision")
 
     swh_rev_id = gen_swhid("revision", revision)
     swh_rev_id_url = reverse("browse-swhid", url_args={"swhid": swh_rev_id})
     assert_contains(resp, swh_rev_id)
     assert_contains(resp, swh_rev_id_url)
 
     swh_dir_id = gen_swhid("directory", dir_id)
     swh_dir_id_url = reverse("browse-swhid", url_args={"swhid": swh_dir_id})
     assert_contains(resp, swh_dir_id)
     assert_contains(resp, swh_dir_id_url)
 
     if origin_url:
         assert_contains(resp, "swh-take-new-snapshot")
 
     swh_rev_id = gen_swhid(REVISION, revision)
     swh_rev_id_url = reverse("browse-swhid", url_args={"swhid": swh_rev_id})
 
     if origin_url:
         browse_origin_url = reverse(
             "browse-origin", query_params={"origin_url": origin_url}
         )
         assert_contains(resp, f'href="{browse_origin_url}"')
     elif snapshot:
         swh_snp_id = gen_swhid("snapshot", snapshot["id"])
         swh_snp_id_url = reverse("browse-swhid", url_args={"swhid": swh_snp_id})
         assert_contains(resp, f'href="{swh_snp_id_url}"')
 
     swhid_context = {}
     if origin_url:
         swhid_context["origin"] = origin_url
     if snapshot:
         swhid_context["visit"] = gen_swhid(SNAPSHOT, snapshot["id"])
 
     swh_rev_id = gen_swhid(REVISION, revision, metadata=swhid_context)
     swh_rev_id_url = reverse("browse-swhid", url_args={"swhid": swh_rev_id})
     assert_contains(resp, swh_rev_id)
     assert_contains(resp, swh_rev_id_url)
 
     swhid_context["anchor"] = gen_swhid(REVISION, revision)
     swhid_context["path"] = "/"
 
     swh_dir_id = gen_swhid(DIRECTORY, dir_id, metadata=swhid_context)
     swh_dir_id_url = reverse("browse-swhid", url_args={"swhid": swh_dir_id})
     assert_contains(resp, swh_dir_id)
     assert_contains(resp, swh_dir_id_url)
diff --git a/swh/web/tests/common/test_utils.py b/swh/web/tests/common/test_utils.py
index 2db4bf34..c57b8de1 100644
--- a/swh/web/tests/common/test_utils.py
+++ b/swh/web/tests/common/test_utils.py
@@ -1,140 +1,235 @@
 # Copyright (C) 2017-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU Affero General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import datetime
+from urllib.parse import quote
 
 import pytest
 
+from django.conf.urls import url
+from django.test.utils import override_settings
+from django.urls.exceptions import NoReverseMatch
+
 from swh.web.common import utils
 from swh.web.common.exc import BadInputExc
 
 
 def test_shorten_path_noop():
     noops = ["/api/", "/browse/", "/content/symbol/foobar/"]
 
     for noop in noops:
         assert utils.shorten_path(noop) == noop
 
 
 def test_shorten_path_sha1():
     sha1 = "aafb16d69fd30ff58afdd69036a26047f3aebdc6"
     short_sha1 = sha1[:8] + "..."
 
     templates = [
         "/api/1/content/sha1:%s/",
         "/api/1/content/sha1_git:%s/",
         "/api/1/directory/%s/",
         "/api/1/content/sha1:%s/ctags/",
     ]
 
     for template in templates:
         assert utils.shorten_path(template % sha1) == template % short_sha1
 
 
 def test_shorten_path_sha256():
     sha256 = "aafb16d69fd30ff58afdd69036a26047" "213add102934013a014dfca031c41aef"
     short_sha256 = sha256[:8] + "..."
 
     templates = [
         "/api/1/content/sha256:%s/",
         "/api/1/directory/%s/",
         "/api/1/content/sha256:%s/filetype/",
     ]
 
     for template in templates:
         assert utils.shorten_path(template % sha256) == template % short_sha256
 
 
 @pytest.mark.parametrize(
     "input_timestamp, output_date",
     [
         (
             "2016-01-12",
             datetime.datetime(2016, 1, 12, 0, 0, tzinfo=datetime.timezone.utc),
         ),
         (
             "2016-01-12T09:19:12+0100",
             datetime.datetime(2016, 1, 12, 8, 19, 12, tzinfo=datetime.timezone.utc),
         ),
         (
             "2007-01-14T20:34:22Z",
             datetime.datetime(2007, 1, 14, 20, 34, 22, tzinfo=datetime.timezone.utc),
         ),
     ],
 )
 def test_parse_iso8601_date_to_utc_ok(input_timestamp, output_date):
     assert utils.parse_iso8601_date_to_utc(input_timestamp) == output_date
 
 
 @pytest.mark.parametrize(
     "invalid_iso8601_timestamp", ["Today is January 1, 2047 at 8:21:00AM", "1452591542"]
 )
 def test_parse_iso8601_date_to_utc_ko(invalid_iso8601_timestamp):
     with pytest.raises(BadInputExc):
         utils.parse_iso8601_date_to_utc(invalid_iso8601_timestamp)
 
 
 def test_format_utc_iso_date():
     assert (
         utils.format_utc_iso_date("2017-05-04T13:27:13+02:00")
         == "04 May 2017, 11:27 UTC"
     )
 
 
 def test_gen_path_info():
     input_path = "/home/user/swh-environment/swh-web/"
     expected_result = [
         {"name": "home", "path": "home"},
         {"name": "user", "path": "home/user"},
         {"name": "swh-environment", "path": "home/user/swh-environment"},
         {"name": "swh-web", "path": "home/user/swh-environment/swh-web"},
     ]
     path_info = utils.gen_path_info(input_path)
     assert path_info == expected_result
 
     input_path = "home/user/swh-environment/swh-web"
     path_info = utils.gen_path_info(input_path)
     assert path_info == expected_result
 
 
 def test_rst_to_html():
     rst = (
         "Section\n"
         "=======\n\n"
         "**Some strong text**\n\n"
         "Subsection\n"
         "----------\n\n"
         "* This is a bulleted list.\n"
         "* It has two items, the second\n"
         "  item uses two lines.\n"
         "\n"
         "1. This is a numbered list.\n"
         "2. It has two items too.\n"
         "\n"
         "#. This is a numbered list.\n"
         "#. It has two items too.\n"
     )
 
     expected_html = (
         '<div class="swh-rst"><h1 class="title">Section</h1>\n'
         "<p><strong>Some strong text</strong></p>\n"
         '<div class="section" id="subsection">\n'
         "<h2>Subsection</h2>\n"
         '<ul class="simple">\n'
         "<li><p>This is a bulleted list.</p></li>\n"
         "<li><p>It has two items, the second\n"
         "item uses two lines.</p></li>\n"
         "</ul>\n"
         '<ol class="arabic simple">\n'
         "<li><p>This is a numbered list.</p></li>\n"
         "<li><p>It has two items too.</p></li>\n"
         "<li><p>This is a numbered list.</p></li>\n"
         "<li><p>It has two items too.</p></li>\n"
         "</ol>\n"
         "</div>\n"
         "</div>"
     )
 
     assert utils.rst_to_html(rst) == expected_html
+
+
+def sample_test_view(request, string, number):
+    pass
+
+
+def sample_test_view_no_url_args(request):
+    pass
+
+
+urlpatterns = [
+    url(
+        r"^sample/test/(?P<string>.+)/view/(?P<number>[0-9]+)/$",
+        sample_test_view,
+        name="sample-test-view",
+    ),
+    url(
+        r"^sample/test/view/no/url/args/$",
+        sample_test_view_no_url_args,
+        name="sample-test-view-no-url-args",
+    ),
+]
+
+
+@override_settings(ROOT_URLCONF=__name__)
+def test_reverse_url_args_only_ok():
+    string = "foo"
+    number = 55
+    url = utils.reverse(
+        "sample-test-view", url_args={"string": string, "number": number}
+    )
+    assert url == f"/sample/test/{string}/view/{number}/"
+
+
+@override_settings(ROOT_URLCONF=__name__)
+def test_reverse_url_args_only_ko():
+    string = "foo"
+    with pytest.raises(NoReverseMatch):
+        utils.reverse("sample-test-view", url_args={"string": string, "number": string})
+
+
+@override_settings(ROOT_URLCONF=__name__)
+def test_reverse_no_url_args():
+    url = utils.reverse("sample-test-view-no-url-args")
+    assert url == "/sample/test/view/no/url/args/"
+
+
+@override_settings(ROOT_URLCONF=__name__)
+def test_reverse_query_params_only():
+    start = 0
+    scope = "foo"
+    url = utils.reverse(
+        "sample-test-view-no-url-args", query_params={"start": start, "scope": scope}
+    )
+    assert url == f"/sample/test/view/no/url/args/?scope={scope}&start={start}"
+
+    url = utils.reverse(
+        "sample-test-view-no-url-args", query_params={"start": start, "scope": None}
+    )
+    assert url == f"/sample/test/view/no/url/args/?start={start}"
+
+
+@override_settings(ROOT_URLCONF=__name__)
+def test_reverse_query_params_encode():
+    libname = "libstc++"
+    url = utils.reverse(
+        "sample-test-view-no-url-args", query_params={"libname": libname}
+    )
+    assert url == f"/sample/test/view/no/url/args/?libname={quote(libname, safe='/;:')}"
+
+
+@override_settings(ROOT_URLCONF=__name__)
+def test_reverse_url_args_query_params():
+    string = "foo"
+    number = 55
+    start = 10
+    scope = "bar"
+    url = utils.reverse(
+        "sample-test-view",
+        url_args={"string": string, "number": number},
+        query_params={"start": start, "scope": scope},
+    )
+    assert url == f"/sample/test/{string}/view/{number}/?scope={scope}&start={start}"
+
+
+@override_settings(ROOT_URLCONF=__name__)
+def test_reverse_absolute_uri(request_factory):
+    request = request_factory.get(utils.reverse("sample-test-view-no-url-args"))
+    url = utils.reverse("sample-test-view-no-url-args", request=request)
+    assert url == f"http://{request.META['SERVER_NAME']}/sample/test/view/no/url/args/"