probe if sha before exec git (#21467)

modules/git/repo_commit.go

@@ -154,8 +154,8 @@ func (repo *Repository) searchCommits(id SHA1, opts SearchCommitsOptions) ([]*Co
 	// then let's iterate over them
 	if len(opts.Keywords) > 0 {
 		for _, v := range opts.Keywords {
-			// ignore anything below 4 characters as too unspecific
-			if len(v) >= 4 {
+			// ignore anything not matching a valid sha pattern
+			if IsValidSHAPattern(v) {
 				// create new git log command with 1 commit limit
 				hashCmd := NewCommand(repo.Ctx, "log", "-1", prettyLogFormat)
 				// add previous arguments except for --grep and --all