Commit diff count is off for repos migrated from GitHub

[harryzcy]

Description

For releases that got migrated from GitHub, the commit diff between the tag and refs/heads/main is off for some releases. Compared to the actual diff, the count on Gitea is in short of 1. Also, the diff on specific release page is showing 0 instead of the correct value.

The issue seemly only happens when a release is tagged against refs/heads/main instead of main on GitHub, and then get migrated. It's also unclear if the existence of a draft release is linked to it. It needs further investigations.

Examples:

Releases listing page (/owner/repo/releases):

Specific release page (/owner/repo/releases/tag/tag_name):

The correct diff on GitHub:

Gitea Version

0c83944

Can you reproduce the bug on the Gitea demo site?

No

Log Gist

No response

Screenshots

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Git Version

No response

Operating System

No response

How are you running Gitea?

Built from source from 0c83944

Database

No response