Fix 500 Error with branch and tag sharing the same name #15592 (#16040)

* Fix 500 Error with branch and tag sharing the same name #15592

Fixed 500 error while create Pull request when there are more
than one sources (branch, tag) with the same name

Fix #15592

Signed-off-by: Viktor Yakovchuk <viktor@yakovchuk.net>

* fix logging

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: 6543 <6543@obermui.de>

modules/git/repo.go

@@ -225,6 +225,13 @@ func Push(repoPath string, opts PushOptions) error {
 			}
 			err.GenerateMessage()
 			return err
+		} else if strings.Contains(errbuf.String(), "matches more than one") {
+			err := &ErrMoreThanOne{
+				StdOut: outbuf.String(),
+				StdErr: errbuf.String(),
+				Err:    err,
+			}
+			return err
 		}
 	}