User facing messages for AGit errors (#33012)

Adds user facing messages to errors when submitting agit pull request
Tries to highlight the returned error more and fixes agit suggestion to
create PR on first submission.

Closes: https://github.com/go-gitea/gitea/issues/32965

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

cmd/serv.go

@@ -104,7 +104,10 @@ func fail(ctx context.Context, userMessage, logMsgFmt string, args ...any) error
 	// There appears to be a chance to cause a zombie process and failure to read the Exit status
 	// if nothing is outputted on stdout.
 	_, _ = fmt.Fprintln(os.Stdout, "")
-	_, _ = fmt.Fprintln(os.Stderr, "Gitea:", userMessage)
+	// add extra empty lines to separate our message from other git errors to get more attention
+	_, _ = fmt.Fprintln(os.Stderr, "error:")
+	_, _ = fmt.Fprintln(os.Stderr, "error:", userMessage)
+	_, _ = fmt.Fprintln(os.Stderr, "error:")
 
 	if logMsgFmt != "" {
 		logMsg := fmt.Sprintf(logMsgFmt, args...)

routers/private/hook_proc_receive.go

@@ -4,9 +4,11 @@
 package private
 
 import (
+	"errors"
 	"net/http"
 
-	repo_model "code.gitea.io/gitea/models/repo"
+	issues_model "code.gitea.io/gitea/models/issues"
+	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/private"
@@ -25,10 +27,16 @@ func HookProcReceive(ctx *gitea_context.PrivateContext) {
 
 	results, err := agit.ProcReceive(ctx, ctx.Repo.Repository, ctx.Repo.GitRepo, opts)
 	if err != nil {
-		if repo_model.IsErrUserDoesNotHaveAccessToRepo(err) {
+		if errors.Is(err, issues_model.ErrMustCollaborator) {
-			ctx.Error(http.StatusBadRequest, "UserDoesNotHaveAccessToRepo", err.Error())
+			ctx.JSON(http.StatusUnauthorized, private.Response{
+				Err: err.Error(), UserMsg: "You must be a collaborator to create pull request.",
+			})
+		} else if errors.Is(err, user_model.ErrBlockedUser) {
+			ctx.JSON(http.StatusUnauthorized, private.Response{
+				Err: err.Error(), UserMsg: "Cannot create pull request because you are blocked by the repository owner.",
+			})
 		} else {
-			log.Error(err.Error())
+			log.Error("agit.ProcReceive failed: %v", err)
 			ctx.JSON(http.StatusInternalServerError, private.Response{
 				Err: err.Error(),
 			})

services/agit/agit.go

@@ -153,7 +153,7 @@ func ProcReceive(ctx context.Context, repo *repo_model.Repository, gitRepo *git.
 				OriginalRef:       opts.RefFullNames[i],
 				OldOID:            objectFormat.EmptyObjectID().String(),
 				NewOID:            opts.NewCommitIDs[i],
-				IsCreatePR:        true,
+				IsCreatePR:        false, // AGit always creates a pull request so there is no point in prompting user to create one
 				URL:               fmt.Sprintf("%s/pulls/%d", repo.HTMLURL(), pr.Index),
 				ShouldShowMessage: setting.Git.PullRequestPushMessage && repo.AllowsPulls(ctx),
 				HeadBranch:        headBranch,