fix detect force push failure on deletion of protected branches (#5522)

cmd/hook.go

@@ -112,10 +112,15 @@ func runHookPreReceive(c *cli.Context) error {
 		branchName := strings.TrimPrefix(refFullName, git.BranchPrefix)
 		protectBranch, err := private.GetProtectedBranchBy(repoID, branchName)
 		if err != nil {
-			log.GitLogger.Fatal(2, "retrieve protected branches information failed")
+			fail("Internal error", fmt.Sprintf("retrieve protected branches information failed: %v", err))
 		}
 
 		if protectBranch != nil && protectBranch.IsProtected() {
+			// check and deletion
+			if newCommitID == git.EmptySHA {
+				fail(fmt.Sprintf("branch %s is protected from deletion", branchName), "")
+			}
+
 			// detect force push
 			if git.EmptySHA != oldCommitID {
 				output, err := git.NewCommand("rev-list", "--max-count=1", oldCommitID, "^"+newCommitID).RunInDir(repoPath)
@@ -126,10 +131,6 @@ func runHookPreReceive(c *cli.Context) error {
 				}
 			}
 
-			// check and deletion
-			if newCommitID == git.EmptySHA {
-				fail(fmt.Sprintf("branch %s is protected from deletion", branchName), "")
-			} else {
 			userID, _ := strconv.ParseInt(userIDStr, 10, 64)
 			canPush, err := private.CanUserPush(protectBranch.ID, userID)
 			if err != nil {
@@ -139,7 +140,6 @@ func runHookPreReceive(c *cli.Context) error {
 			}
 		}
 	}
-	}
 
 	return nil
 }