CODEOWNERS trigger on PR update also activated by merge commit

[splitt3r]

Description

The recent change in behaviour introduced in #33744 / reported by #33490 is also triggered by files which are changed in a merge commit (update branch button in the PR) but not really touched by the code changes in the PR. This leads to quite some mail / reviewer spam in our environment.

Steps to reproduce:

• Create CODEOWNERS file for test.txt on main
• Create PR which changes a file (not test.txt)
• Change test.txt on main branch
• Update PR branch via Gitea UI
• Now the CODEOWNERS for test.txt will be assigned even if the PR does not change text.txt

Gitea Version

1.23.7

Can you reproduce the bug on the Gitea demo site?

Yes

Log Gist

No response

Screenshots

No response

Git Version

No response

Operating System

No response

How are you running Gitea?

Ubuntu installation

Database

None

[lunny]

When clicking update the branch, a new commit will be listed on the pull request commits tab like below.

[splitt3r]

Exactly. So this is intended behaviour? The merge commit indeed touches the file. But the PR does not really change it.

[lunny]

Yes. The last commit of this PR is a merge commit which contains the change of the file. But from the PR's changed files, the file is not changed. Maybe it should always check the changed files but not pushed commits.