fix(git): parse co-author trailers that are not RFC 5322 addresses (#39076)

Bot co-authors like `dependabot[bot]` render as one long string with the
email inside the name, and never get truncated, so they overflow the
column.

Co-author idents are parsed with `net/mail`, but a git ident isn't an
email address. `mail.ParseAddress` rejects the whole value when the name
holds characters RFC 5322 reserves, like a `[bot]` suffix or a comma, so
the error branch keeps the raw trailer as the display name and throws
the address away. No address means no `mailto:` link, and the anchor is
what `.avatar-stack-names` truncates.

So parse the angle-addr ourselves when `net/mail` won't take it.
Splitting on the last `<` is safe because git strips angle brackets from
idents. The bare-name branch gets the class too.

Fixes https://github.com/go-gitea/gitea/issues/38949

modules/git/commit_message.go

@@ -171,16 +171,24 @@ func (c *Commit) AllAuthorIdentities() []*CommitIdentity {
 
 	addAuthor(c.Author.Name, c.Author.Email, commitIdentityRoleAuthor)
 	for _, coAuthorValue := range trailerCoAuthors {
-		addr, err := mail.ParseAddress(coAuthorValue)
-		coAuthorName, coAuthorEmail := coAuthorValue, ""
-		if err == nil {
-			coAuthorName, coAuthorEmail = addr.Name, addr.Address
-		}
+		coAuthorName, coAuthorEmail := parseCommitIdentityValue(coAuthorValue)
 		addAuthor(coAuthorName, coAuthorEmail, commitIdentityRoleCoAuthor)
 	}
 	return c.allAuthors
 }
 
+// Git identities are not RFC 5322 addresses: net/mail rejects names like "dependabot[bot]", so fall back to the angle-addr.
+func parseCommitIdentityValue(value string) (name, email string) {
+	if addr, err := mail.ParseAddress(value); err == nil {
+		return addr.Name, addr.Address
+	}
+	begin, end := strings.LastIndex(value, "<"), strings.LastIndex(value, ">")
+	if begin == -1 || end < begin {
+		return value, ""
+	}
+	return strings.TrimSpace(value[:begin]), strings.TrimSpace(value[begin+1 : end])
+}
+
 func (c *Commit) CoAuthorIdentities() (coAuthors []*CommitIdentity) {
 	all := c.AllAuthorIdentities()
 	if len(all) == 0 {