Handle push rejection in branch and upload (#10854)

* Handle push rejections and push out-of-date in branch creation and
file upload.
* Remove the duplicated sanitize from services/pull/merge
* Move the errors Err(Merge)PushOutOfDate and ErrPushRejected to
modules/git
* Handle errors better in the upload file dialogs

Fix #10460

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

modules/git/repo.go

@@ -255,7 +255,31 @@ func Push(repoPath string, opts PushOptions) error {
 		cmd.AddArguments("-f")
 	}
 	cmd.AddArguments("--", opts.Remote, opts.Branch)
-	_, err := cmd.RunInDirWithEnv(repoPath, opts.Env)
+	var outbuf, errbuf strings.Builder
+
+	err := cmd.RunInDirTimeoutEnvPipeline(opts.Env, -1, repoPath, &outbuf, &errbuf)
+	if err != nil {
+		if strings.Contains(errbuf.String(), "non-fast-forward") {
+			return &ErrPushOutOfDate{
+				StdOut: outbuf.String(),
+				StdErr: errbuf.String(),
+				Err:    err,
+			}
+		} else if strings.Contains(errbuf.String(), "! [remote rejected]") {
+			err := &ErrPushRejected{
+				StdOut: outbuf.String(),
+				StdErr: errbuf.String(),
+				Err:    err,
+			}
+			err.GenerateMessage()
+			return err
+		}
+	}
+
+	if errbuf.Len() > 0 && err != nil {
+		return fmt.Errorf("%v - %s", err, errbuf.String())
+	}
+
 	return err
 }