OpenCL highlighting causes internal server error

I get error 500 when try to open an OpenCL source code in GitLab. The file has ".cl" extension.

The error in /var/log/gitlab/gitlab-rails/production.log:

Started GET "/CMIC/NifTK/blob/da07065b808bb57945bc2d41541bad2d71041e61/Code/Gui/MITK/Modules/niftkVL/Resources/TriangleSorter.cl" for 128.16.8.132 at 2015-05-18 14:18:20 +0100
Processing by Projects::BlobController#show as HTML
  Parameters: {"namespace_id"=>"CMIC", "project_id"=>"NifTK", "id"=>"da07065b808bb57945bc2d41541bad2d71041e61/Code/Gui/MITK/Modules/niftkVL/Resources/TriangleSorter.cl"}
Completed 500 Internal Server Error in 685ms

ActionView::Template::Error (empty stack!):
     8:           %i.fa.fa-link
     9:           = i
    10:   :preserve
    11:     #{highlight(blob.name, blob.data)}
  app/helpers/blob_helper.rb:16:in `highlight'
  app/views/shared/_file_highlight.html.haml:11:in `_app_views_shared__file_highlight_html_haml___2743352872942926358_100507040'
  app/views/projects/blob/_text.html.haml:11:in `_app_views_projects_blob__text_html_haml__3603389847585745576_100391020'
  app/views/projects/blob/_blob.html.haml:33:in `_app_views_projects_blob__blob_html_haml___3248816930354988193_99143700'
  app/views/projects/blob/show.html.haml:5:in `_app_views_projects_blob_show_html_haml__1113731428455583526_98820380'

GitLab version: GitLab 7.9.0 16d6f0e3

/cc @rumpelsepp

This may be a duplicate of #1521 (closed). I'm guessing this line-by-line syntax highlighting isn't the right approach and causes parse errors in certain cases.

It looks the same, indeed, except that it was not the blame view in my case.

Instead of adding special cases for new languages, maybe we could fallback to plain text if the parser fails?

That was just a suggested hack to workaround the issue for that user. Do you have a sample of the .cl text that is failing?

I think in this case it does make sense to catch the failure and fallback to plain text.

This line made the parser fail:

// 2) Create an histogram of d=2^b digits entries

When we removed this, the file was displayed with very basic syntax highlighting. (String literals were coloured but keywords not.)

mentioned in merge request !683 (merged)

This should be fixed when !683 (merged) gets merged
A real fix needs to be done in the rugments gem, but for now it'll fall back to plaintext rendering if an error occurs.

Status changed to closed by commit 9fe8c74d

mentioned in commit tnir/gitlab-ce@98f12863

mentioned in merge request !14785