RefService::FindAllTags: slice bounds out of range

Summary

FindAllTags panics:

runtime error: slice bounds out of range [10225:10224]

Stack trace

  File "tag.go", line 126, in buildAnnotatedTag
    signature := string(tag.Message[index : bytes.Index(tag.Message[index:], []byte("\n"))+index])
  File "tag.go", line 38, in GetTagCatfile
    tag, err := buildAnnotatedTag(c, tagID, tagName, header, body, trimLen, trimRightNewLine)
  File "refs.go", line 379, in parseTagLine
    tag, err := gitlog.GetTagCatfile(c, tagID, refName, true, true)
  File "refs.go", line 103, in parseAndReturnTags
    tag, err := parseTagLine(c, scanner.Text())

This sounds like bytes.Index(tag.Message[index:], []byte("\n")) is returning -1, aka there is no newline.

Environment

gitaly version: 12.9.2

Original ticket: https://salsa.debian.org/salsa/support/-/issues/205