[GITEA] Don't consider orphan branches as recently pushed

When displaying the recently pushed branches banner, don't display
branches that have no common history with the default branch. These
branches are usually not meant to be merged, so the banner is just noise
in this case.

Refs: https://codeberg.org/forgejo/forgejo/pulls/2196

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
(cherry picked from commit e1fba517f4)

routers/web/repo/view.go

@@ -1053,7 +1053,43 @@ func renderCode(ctx *context.Context) {
 			}
 		}
 
-		ctx.Data["RecentlyPushedNewBranches"] = branches
+		// Filter out branches that have no relation to the default branch of
+		// the repository.
+		var filteredBranches []*git_model.Branch
+		for _, branch := range branches {
+			repo, err := branch.GetRepo(ctx)
+			if err != nil {
+				continue
+			}
+			gitRepo, err := git.OpenRepository(ctx, repo.RepoPath())
+			if err != nil {
+				continue
+			}
+			defer gitRepo.Close()
+			head, err := gitRepo.GetCommit(branch.CommitID)
+			if err != nil {
+				continue
+			}
+			defaultBranch, err := gitRepo.GetDefaultBranch()
+			if err != nil {
+				continue
+			}
+			defaultBranchHead, err := gitRepo.GetCommit(defaultBranch)
+			if err != nil {
+				continue
+			}
+
+			hasMergeBase, err := head.HasPreviousCommit(defaultBranchHead.ID)
+			if err != nil {
+				continue
+			}
+
+			if hasMergeBase {
+				filteredBranches = append(filteredBranches, branch)
+			}
+		}
+
+		ctx.Data["RecentlyPushedNewBranches"] = filteredBranches
 	}
 
 PostRecentBranchCheck: