Branches not at ref commit ID should not be listed as Merged (#9614)

Once a branch has been merged if the commit ID no longer equals that of
the pulls ref commit id don't offer to delete the branch on the pull screen
and don't list it as merged on branches.

Fix #9201

When looking at the pull page we should also get the commits from the refs/pulls/x/head

Fix #9158

1 files changed, 44 insertions, 0 deletions

diff --git a/routers/repo/branch.go b/routers/repo/branch.go
index b0a1efc5b9..df6e0bf21f 100644
--- a/routers/repo/branch.go
+++ b/routers/repo/branch.go
@@ -16,6 +16,7 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/repofiles"
 	"code.gitea.io/gitea/modules/util"
+	"gopkg.in/src-d/go-git.v4/plumbing"
 )
 
 const (
@@ -33,6 +34,7 @@ type Branch struct {
 	CommitsAhead      int
 	CommitsBehind     int
 	LatestPullRequest *models.PullRequest
+	MergeMovedOn      bool
 }
 
 // Branches render repository branch page
@@ -185,6 +187,12 @@ func loadBranches(ctx *context.Context) []*Branch {
 		return nil
 	}
 
+	repoIDToRepo := map[int64]*models.Repository{}
+	repoIDToRepo[ctx.Repo.Repository.ID] = ctx.Repo.Repository
+
+	repoIDToGitRepo := map[int64]*git.Repository{}
+	repoIDToGitRepo[ctx.Repo.Repository.ID] = ctx.Repo.GitRepo
+
 	branches := make([]*Branch, len(rawBranches))
 	for i := range rawBranches {
 		commit, err := rawBranches[i].GetCommit()
@@ -213,11 +221,46 @@ func loadBranches(ctx *context.Context) []*Branch {
 			ctx.ServerError("GetLatestPullRequestByHeadInfo", err)
 			return nil
 		}
+		headCommit := commit.ID.String()
+
+		mergeMovedOn := false
 		if pr != nil {
+			pr.HeadRepo = ctx.Repo.Repository
 			if err := pr.LoadIssue(); err != nil {
 				ctx.ServerError("pr.LoadIssue", err)
 				return nil
 			}
+			if repo, ok := repoIDToRepo[pr.BaseRepoID]; ok {
+				pr.BaseRepo = repo
+			} else if err := pr.LoadBaseRepo(); err != nil {
+				ctx.ServerError("pr.LoadBaseRepo", err)
+				return nil
+			} else {
+				repoIDToRepo[pr.BaseRepoID] = pr.BaseRepo
+			}
+
+			if pr.HasMerged {
+				baseGitRepo, ok := repoIDToGitRepo[pr.BaseRepoID]
+				if !ok {
+					baseGitRepo, err = git.OpenRepository(pr.BaseRepo.RepoPath())
+					if err != nil {
+						ctx.ServerError("OpenRepository", err)
+						return nil
+					}
+					defer baseGitRepo.Close()
+					repoIDToGitRepo[pr.BaseRepoID] = baseGitRepo
+				}
+				pullCommit, err := baseGitRepo.GetRefCommitID(pr.GetGitRefName())
+				if err != nil && err != plumbing.ErrReferenceNotFound {
+					ctx.ServerError("GetBranchCommitID", err)
+					return nil
+				}
+				if err == nil && headCommit != pullCommit {
+					// the head has moved on from the merge - we shouldn't delete
+					mergeMovedOn = true
+				}
+			}
+
 		}
 
 		isIncluded := divergence.Ahead == 0 && ctx.Repo.Repository.DefaultBranch != branchName
@@ -230,6 +273,7 @@ func loadBranches(ctx *context.Context) []*Branch {
 			CommitsAhead:      divergence.Ahead,
 			CommitsBehind:     divergence.Behind,
 			LatestPullRequest: pr,
+			MergeMovedOn:      mergeMovedOn,
 		}
 	}