Not showing diff when running as Flatpak

[Marukesu]

What Happened

When running as flatpak, code don't show the diff of the opened file. looking at the terminal output, it seems it is triggering a assertion on ggit_diff_foreach.

Ggit-CRITICAL **: 15:26:01.110: ggit_diff_foreach: assertion 'file_cb != NULL && binary_cb != NULL && hunk_cb != NULL && line_cb != NULL' failed

Expected Behavior

That the diff is shown like in the non-sandboxed version.

Steps to Reproduce

1. Run code flatpak.
2. Open a file from a git project.
3. Modify the file and see that the diff is not shown.

Platform Information

elementaryOS 6.0 Early Access.
code from master branch.

[jeremypw]

Only affects doc gutter - the sidebar shows git status.

[jeremypw]

Looks like (maybe) a git library version issue? Strangely, even if I verify that the line callback is not null immediately before calling the iterator on the diff, I still get this error. This both with a separate function or with a closure used as the callback. So the error seems to be wrong or misleading.

[jeremypw]

As a work around, providing dummy callbacks instead of null for callbacks that are not used seems to work. Pushing a PR.

[jeremypw]

Closing as due to an upstream bug which is due to be fixed.