Encoding::UndefinedConversionError: "\x89" from ASCII-8BIT to UTF-8

Steps to reproduce

1. Clone the wiki repository locally
2. Copy a PNG file to the local repository and rename it to this_is_a_png.md
3. Commit and push
4. View the new page

Sentry details

https://sentry.gitlab.net/gitlab/gitlabcom/issues/1637294/?referrer=gitlab_plugin

Encoding::UndefinedConversionError: "\x89" from ASCII-8BIT to UTF-8
  commonmarker.rb:41:in `encode'
    text = text.encode('UTF-8')
  commonmarker.rb:41:in `render_doc'
    text = text.encode('UTF-8')
  banzai/filter/markdown_engines/common_mark.rb:47:in `render'
    doc = CommonMarker.render_doc(text, PARSE_OPTIONS, EXTENSIONS)
  banzai/filter/markdown_filter.rb:14:in `call'
    @renderer.render(@text).rstrip
  html/pipeline/filter.rb:129:in `call'
    new(doc, context, result).call
...
(208 additional frame(s) were not displayed)

Encoding::UndefinedConversionError: "\x89" from ASCII-8BIT to UTF-8

added typebug label

added Category:Wiki devopscreate + 1 deleted label

added priority4 severity4 labels

added backend label

mentioned in issue #220717 (closed)

This error happens when someone tries to pretend that a binary blob (like an image) is a plaintext markup file. It's unlikely to happen accidentally, so I've labeled this ~P4 ~S4 (we haven't seen any such errors in Sentry, besides this one, which was me).

@cdybenko We could probably check if a wiki page is a binary blob instead of a plaintext file as it should be. In this case, should we just display an error message to the view and render nothing?

We could probably check if a wiki page is a binary blob instead of a plaintext file as it should be.

@.luke looks like we can use Gitlab::EncodingHelper.detect_binary? for this

It's currently a bit weird because we end up loading the blob again through a separate Gitaly RPC in https://gitlab.com/gitlab-org/gitlab/blob/1191ae1d4aea2cb2e5fa78d5f18597843e59d2f0/app/controllers/concerns/wiki_actions.rb#L225, but that's probably acceptable for this edge case, and will be fixed when we get rid of the custom wiki RPCs.

changed milestone to %Backlog

added [deprecated] Accepting merge requests label

added sectiondev label

added groupeditor [DEPRECATED] label and removed 1 deleted label

A user has reported seeing a similar issue - #301154 (closed)

This seems to be related to Polish language characters rather than png images.

added vintage label

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Hi @jobbot ,

Based on the policy for inactive bugs, this issue is now being closed.

If you think this bug still exists, and is reproducible with the latest stable version of GitLab, please reopen this issue.

Thanks for your contributions to make GitLab better!

closed

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