"call of nil" exception when comparing images

[saitho]

• Gitea version (or commit ref): master
• Can you reproduce the bug at https://try.gitea.io:
  • Yes: https://try.gitea.io/saitho/test2/pulls/3/files

Description

Opening a pull request that adds or modifies an image works fine.

However in the file view of the pull request an error is thrown:

template: repo/diff/image_diff:14:29: executing "repo/diff/image_diff" at <call .root.FileExistsInBaseCommit .file.OldName>: error calling call: call of nil

[egrekov]

Today I caught a similar error when opening a commit.
template: repo/diff/image_diff:14:29: executing "repo/diff/image_diff" at <call .root.FileExistsInBaseCommit .file.OldName>: error calling call: call of nil

© Gitea Version: 1.10.0+dev-326-gc05b89a5a

[guillep2k]

@saitho The easiest way to reproduce this problem is to check a commit that adds an image. The problem is that the commit URL is: /{user}/{repo}/commit/{commit-sha}, and this routes into:

gitea/routers/repo/commit.go

Line 193 in f8882f4

func Diff(ctx *context.Context) {

Diff() does not set FileExistsInBaseCommit (or other image information), nor calls PrepareCompareDiff(), thus the error.

I've noticed that you've authored #6784 . Is it possible for you to create a new PR fixing this problem?

Perhaps a temporary workaround is to change:

gitea/templates/repo/diff/box.tmpl

Lines 113 to 115 in f8882f4

	{{if $isImage}}
	{{template "repo/diff/image_diff" dict "file" . "root" $}}
	{{else}}

Into something like:

{{if and $isImage ($root.FileExistsInBaseCommit != nil)}}
	{{template "repo/diff/image_diff" dict "file" . "root" $}}
{{else}}

Or something around those lines (I'm not quite familiar with macaron syntax).

[saitho]

Thanks for your analysis. I added the missing lines (probably lost while rebasing branches) and did some minor adjustments to the image compare functionality. :D