This uses the linkifier index among the list of linkifiers in the
replacement as the priority to order the replacement order for
patterns in the topic. This avoids having multiple overlapping matches
that each produce a link.
The linkifier with the lowest id will be prioritized when its pattern
overlaps with another. Linkifiers are prioritized over raw URLs.
Note that the same algorithm is used for local echoing and the
backend markdown processor.
Fixes#23715.
Signed-off-by: Zixuan James Li <p359101898@gmail.com>
This explicitly enforces ordering on the linkifiers. This is useful when
there are overlapping linkifier patterns that matches the same text. In
our current linkifier implementation, this order affects how the
patterns are handled in the markdown processor, with the earlier ones
being prioritized.
Signed-off-by: Zixuan James Li <p359101898@gmail.com>
The same pattern being matched multiple times in a topic cannot be
properly ordered using topic_name.find(match_text) and etc. when there
are multiple matches of the same pattern in the topic.
Signed-off-by: Zixuan James Li <p359101898@gmail.com>
9381a3bd45 added support for linkifier pattern URLs containing
`%20`-style escapes, but only did so for the codepath which is used in
the message body -- topic links did not understand them.
Expand the support to include when they are substituted into topics.
These were useful as a transitional workaround to ignore type errors
that only show up with django-stubs, while avoiding errors about
unused type: ignore comments without django-stubs. Now that the
django-stubs transition is complete, switch to type: ignore comments
so that mypy will tell us if they become unnecessary. Many already
have.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Due to mismatches between the URL parsers in Python and browsers, it
was possible to hoodwink rewrite_local_links_to_relative into
generating links that browsers would interpret as absolute.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
We now use MODERATORS_GROUP_NAME instead of writing
the actual group name at multiple places, so that we
can have all the group names coded at one place only.
Now the following characters are allowed before @-mentions and stream
references (starting with #) for proper rendering - {, [, /.
This commit makes the markdown rendering consistent with autocomplete
(anything that is autocompleted is also rendered properly).
This commit removes the instances of using "Stream.objects.create"
in tests with make_stream function. This change will help us to
avoid adding code for things to be done after creating streams in
multiple places. We can instead just add it in make_stream function
only.
The `get_link_embed_data` / `link_embed_data_from_cache` pair as
introduced in c93f1d4eda uses the cache
as a temporary store inside of the `embed_links` worker; this means
that it must be durable storage, or the worker will stall and re-fetch
the same links to preview them.
Switch to plumbing through the fetched URL embed data as an parameter
to the Markdown evaluation which uses them, rather than using the
cache as an intermediary. This frees up the cache to be merely a
non-durable cache.
As a side-effect, this removes get_cache_with_key, and
link_embed_data_from_cache which was its only callsite.
`prepare_linkifier_pattern`, as of db934be064, adds a match to the
end of the regex, of either the end of string, or a non-word character
-- this is in place of a negative look-ahead, which is no longer
possible in re2. This causes the regex to consume trailing
whitespace, and thus not be able to match twice in succession with
`pattern.finditer` -- "#1234#5678" fails to match because the space
is consumed by the first match of the regex.
Rather than use `pattern.finditer`, write own own version, which
rewinds over the non-word character consumed after the match, if any.
This allows the same "after" non-word character to also satisfy the
"before" of the next match.
Fixes#21502.
Various backend tests use the `PATCH /messages/{msg_id}` endpoint.
For that endpoint, the message ID is encoded in the URL path and
ignored if provided as a parameter in the the query.
Verified that the tests were providing the same message ID to both
the path and then removed the ignored parameter in the query.
This commit ensures that all markdown fixtures have unique
test names by rewriting the names of some of them and adding
a test in `test_markdown.py`.
Earlier this was over-writing the value for same keys in
`load_markdown_tests` in `test_markdown.py`.
Supporting URL percent-encoded bytes is possible using `%%20`, but this
is not necessarily very understandable to end-users, even those that
understand percent encoding.
Allow `%20` in linkifier URL format strings, and transform them into
`%%20` in the pattern just before they are applied in markdown
translation. Care must be taken here, such that already-escaped `%`s
are not escaped an extra time.
We do this before rendering, and not before storage, as
a simplification; the JS-side linkifier at present only understands
`%(foo)s` and thus needs no changes, and to avoid an un-escaping pass
before showing in the admin UI.
Zulip attempts to validate that the regular expressions that admins
enter for linkifiers are well-formatted, and only contain a specific
subset of regex grammar. The process of checking these
properties (via a regex!) can cause denial-of-service via
backtracking.
Furthermore, this validation itself does not prevent the creation of
linkifiers which themselves cause denial-of-service when they are
executed. As the validator accepts literally anything inside of a
`(?P<word>...)` block, any quadratic backtracking expression can be
hidden therein.
Switch user-provided linkifier patterns to be matched in the Markdown
processor by the `re2` library, which is guaranteed constant-time.
This somewhat limits the possible features of the regular
expression (notably, look-head and -behind, and back-references);
however, these features had never been advertised as working in the
context of linkifiers.
A migration removes any existing linkifiers which would not function
under re2, after printing them for posterity during the upgrade; they
are unlikely to be common, and are impossible to fix automatically.
The denial-of-service in the linkifier validator was discovered by
@erik-krogh and @yoff, as GHSL-2021-118.
We do not allow mentioning system user groups for now
because this can lead to circumventing the wildcard
mention restrictions. It will be enabled once we add
a setting to control that.
This is implemented by just ignoring it as one of the
mentioned user group even if the message content
inlcudes the mention syntax for it and the message
is sent normally.
We still keep the for_mention parameter for accessing
user group while sending email and push notifications
as mentioning system user groups will be allowed in
future.
This commit also removes the test for email notifications
for system user groups as we are not allowing mentioning
them.
This commit is only for backend change as we already
exclude the system groups from mention typeaheads and
other UI.
This adds a new class called MessageRenderingResult to contain the
additional properties we added to the Message object (like alert_words)
as well as the rendered content to ensure typesafe reference. No
behavioral change is made except changes in typing.
This is a preparatory change for adding django-stubs to the backend.
Related: #18777
This should help with #17425, where messages with lots of LaTeX are
lost, due to the large expansion factor.
This isn't a total fix for this - large messages with lots of LaTeX
can still end up larger than 1MB, and rendering could timeout, but
this fix should help significantly.
1MB is still small enough that I don't expect we'll run into any DOS
problems - my testing didn't show any problems rendering messages that
contain ~1MB of LaTeX.
This will offer users who are self-hosting to adjust
this value. Moreover, this will help to reduce the
overall time taken to test `test_markdown.py` (since
this can be now overridden with `override_settings`
Django decorator).
This is done as a prep commit for #18641.
?dl=1 causes Dropbox to send Content-Type: application/binary, which
can’t be interpreted by Camo. Use ?raw=1 instead.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Anders Kaseorg
Zixuan James Li
Lauryn Menard
Alex Vandiver
Sahil Batra
N-Shar-ma
Zixuan James Li
Lauryn Menard
Steve Howell
akshatdalton
Dinesh
Mateusz Mandera
Wesley Aptekar-Cassels
Abhijeet Prasad Bodas