Fix pull request update showing too many commits with multiple branches

modules/git/repo_commit.go

@@ -323,6 +323,28 @@ func (repo *Repository) CommitsBetweenLimit(last, before *Commit, limit, skip in
 	return repo.parsePrettyFormatLogToList(bytes.TrimSpace(stdout))
 }
 
+// CommitsBetween returns a list that contains commits between [before, last),
+// excluding commits in baseBranch.
+// If before is detached (removed by reset + push) it is not included.
+func (repo *Repository) CommitsBetweenSkipBase(last, before *Commit, baseBranch string) ([]*Commit, error) {
+	var stdout []byte
+	var err error
+	if before == nil {
+		stdout, _, err = NewCommand(repo.Ctx, "rev-list").AddDynamicArguments(last.ID.String()).AddOptionValues("--not", baseBranch).RunStdBytes(&RunOpts{Dir: repo.Path})
+	} else {
+		stdout, _, err = NewCommand(repo.Ctx, "rev-list").AddDynamicArguments(before.ID.String()+".."+last.ID.String()).AddOptionValues("--not", baseBranch).RunStdBytes(&RunOpts{Dir: repo.Path})
+		if err != nil && strings.Contains(err.Error(), "no merge base") {
+			// future versions of git >= 2.28 are likely to return an error if before and last have become unrelated.
+			// previously it would return the results of git rev-list before last so let's try that...
+			stdout, _, err = NewCommand(repo.Ctx, "rev-list").AddDynamicArguments(before.ID.String(), last.ID.String()).AddOptionValues("--not", baseBranch).RunStdBytes(&RunOpts{Dir: repo.Path})
+		}
+	}
+	if err != nil {
+		return nil, err
+	}
+	return repo.parsePrettyFormatLogToList(bytes.TrimSpace(stdout))
+}
+
 // CommitsBetweenIDs return commits between twoe commits
 func (repo *Repository) CommitsBetweenIDs(last, before string) ([]*Commit, error) {
 	lastCommit, err := repo.GetCommit(last)

services/pull/comment.go

@@ -14,58 +14,6 @@ import (
 	issue_service "code.gitea.io/gitea/services/issue"
 )
 
-type commitBranchCheckItem struct {
-	Commit  *git.Commit
-	Checked bool
-}
-
-func commitBranchCheck(gitRepo *git.Repository, startCommit *git.Commit, endCommitID, baseBranch string, commitList map[string]*commitBranchCheckItem) error {
-	if startCommit.ID.String() == endCommitID {
-		return nil
-	}
-
-	checkStack := make([]string, 0, 10)
-	checkStack = append(checkStack, startCommit.ID.String())
-
-	for len(checkStack) > 0 {
-		commitID := checkStack[0]
-		checkStack = checkStack[1:]
-
-		item, ok := commitList[commitID]
-		if !ok {
-			continue
-		}
-
-		if item.Commit.ID.String() == endCommitID {
-			continue
-		}
-
-		if err := item.Commit.LoadBranchName(); err != nil {
-			return err
-		}
-
-		if item.Commit.Branch == baseBranch {
-			continue
-		}
-
-		if item.Checked {
-			continue
-		}
-
-		item.Checked = true
-
-		parentNum := item.Commit.ParentCount()
-		for i := 0; i < parentNum; i++ {
-			parentCommit, err := item.Commit.Parent(i)
-			if err != nil {
-				return err
-			}
-			checkStack = append(checkStack, parentCommit.ID.String())
-		}
-	}
-	return nil
-}
-
 // getCommitIDsFromRepo get commit IDs from repo in between oldCommitID and newCommitID
 // isForcePush will be true if oldCommit isn't on the branch
 // Commit on baseBranch will skip
@@ -82,47 +30,34 @@ func getCommitIDsFromRepo(ctx context.Context, repo *repo_model.Repository, oldC
 		return nil, false, err
 	}
 
-	if err = oldCommit.LoadBranchName(); err != nil {
+	newCommit, err := gitRepo.GetCommit(newCommitID)
+	if err != nil {
+		return nil, false, err
+	}
+
+	// If old commit is not an ancestor of new commits, it's a force push
+	isAncestor, err := newCommit.HasPreviousCommit(oldCommit.ID)
+	if err != nil {
 		return nil, false, err
 	}
 
-	if len(oldCommit.Branch) == 0 {
+	if !isAncestor {
 		commitIDs = make([]string, 2)
 		commitIDs[0] = oldCommitID
 		commitIDs[1] = newCommitID
 
 		return commitIDs, true, err
 	}
 
-	newCommit, err := gitRepo.GetCommit(newCommitID)
-	if err != nil {
-		return nil, false, err
-	}
-
-	commits, err := newCommit.CommitsBeforeUntil(oldCommitID)
+	// Find commits between new and old commit exclusing base branch commits
+	commits, err := gitRepo.CommitsBetweenSkipBase(newCommit, oldCommit, baseBranch)
 	if err != nil {
 		return nil, false, err
 	}
 
 	commitIDs = make([]string, 0, len(commits))
-	commitChecks := make(map[string]*commitBranchCheckItem)
-
-	for _, commit := range commits {
-		commitChecks[commit.ID.String()] = &commitBranchCheckItem{
-			Commit:  commit,
-			Checked: false,
-		}
-	}
-
-	if err = commitBranchCheck(gitRepo, newCommit, oldCommitID, baseBranch, commitChecks); err != nil {
-		return
-	}
-
 	for i := len(commits) - 1; i >= 0; i-- {
-		commitID := commits[i].ID.String()
-		if item, ok := commitChecks[commitID]; ok && item.Checked {
-			commitIDs = append(commitIDs, commitID)
-		}
+		commitIDs = append(commitIDs, commits[i].ID.String())
 	}
 
 	return commitIDs, isForcePush, err