Disallow extensions with dots, Extension filter checks full extension

[ItsNiklas]

Description

If the option Filter files passed to compiler by extension list is enabled for a language, only the filename ending with the extension will be checked. This may work for most languages, but can be annoying for e.g. the C language. Files like submission.doc can get through just because they end with a c. This is not the intended behavior of this option. Disabling this option allows the team to fully choose the language.

Honestly, I cannot think of any other case except maybe pyc. But I still think this is a small oversight in the code.

Fixes #2218.

Tested on my local development instance. The behaviour described in the issue is now as expected and I couldn't produce any other new bugs.

Bug fix

Check the extension including the dot in the extension loop. This forces the file to end with exactly .c. The ltrim allows the check to complete even if the extensions are accidentally entered with a dot when creating a new language.

Breaking

If filterCompilerFiles is on:

• We now assume that the filename contains a dot. I think this is acceptable since this is a contest control system, and this is the expected behavior when this option is enabled by an admin.
  • Maybe change the FILENAME_REGEX to capture this earlier...

[vmcj]

Hi @ItsNiklas, thank you for the fix. I'll merge this after one of the others also approves (which will most likely be at/after Friday).

[ItsNiklas]

I added the Assert to the Language entity / form.

Had to fix the code that created the delete button because it overode the error message. I added a Doctrine migration because the errors were pretty bad after the entity changed. Hopefully it is correct that way, I wasn't sure.

Thanks