1 files changed, 114 insertions, 0 deletions
diff --git a/services/doctor/mergebase.go b/services/doctor/mergebase.go
new file mode 100644
index 0000000..de460c4
--- /dev/null
+++ b/services/doctor/mergebase.go
@@ -0,0 +1,114 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package doctor
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+	issues_model "code.gitea.io/gitea/models/issues"
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/log"
+
+	"xorm.io/builder"
+)
+
+func iteratePRs(ctx context.Context, repo *repo_model.Repository, each func(*repo_model.Repository, *issues_model.PullRequest) error) error {
+	return db.Iterate(
+		ctx,
+		builder.Eq{"base_repo_id": repo.ID},
+		func(ctx context.Context, bean *issues_model.PullRequest) error {
+			return each(repo, bean)
+		},
+	)
+}
+
+func checkPRMergeBase(ctx context.Context, logger log.Logger, autofix bool) error {
+	numRepos := 0
+	numPRs := 0
+	numPRsUpdated := 0
+	err := iterateRepositories(ctx, func(repo *repo_model.Repository) error {
+		numRepos++
+		return iteratePRs(ctx, repo, func(repo *repo_model.Repository, pr *issues_model.PullRequest) error {
+			numPRs++
+			pr.BaseRepo = repo
+			repoPath := repo.RepoPath()
+
+			oldMergeBase := pr.MergeBase
+
+			if !pr.HasMerged {
+				var err error
+				pr.MergeBase, _, err = git.NewCommand(ctx, "merge-base").AddDashesAndList(pr.BaseBranch, pr.GetGitRefName()).RunStdString(&git.RunOpts{Dir: repoPath})
+				if err != nil {
+					var err2 error
+					pr.MergeBase, _, err2 = git.NewCommand(ctx, "rev-parse").AddDynamicArguments(git.BranchPrefix + pr.BaseBranch).RunStdString(&git.RunOpts{Dir: repoPath})
+					if err2 != nil {
+						logger.Warn("Unable to get merge base for PR ID %d, #%d onto %s in %s/%s. Error: %v & %v", pr.ID, pr.Index, pr.BaseBranch, pr.BaseRepo.OwnerName, pr.BaseRepo.Name, err, err2)
+						return nil
+					}
+				}
+			} else {
+				parentsString, _, err := git.NewCommand(ctx, "rev-list", "--parents", "-n", "1").AddDynamicArguments(pr.MergedCommitID).RunStdString(&git.RunOpts{Dir: repoPath})
+				if err != nil {
+					logger.Warn("Unable to get parents for merged PR ID %d, #%d onto %s in %s/%s. Error: %v", pr.ID, pr.Index, pr.BaseBranch, pr.BaseRepo.OwnerName, pr.BaseRepo.Name, err)
+					return nil
+				}
+				parents := strings.Split(strings.TrimSpace(parentsString), " ")
+				if len(parents) < 2 {
+					return nil
+				}
+
+				refs := append([]string{}, parents[1:]...)
+				refs = append(refs, pr.GetGitRefName())
+				cmd := git.NewCommand(ctx, "merge-base").AddDashesAndList(refs...)
+				pr.MergeBase, _, err = cmd.RunStdString(&git.RunOpts{Dir: repoPath})
+				if err != nil {
+					logger.Warn("Unable to get merge base for merged PR ID %d, #%d onto %s in %s/%s. Error: %v", pr.ID, pr.Index, pr.BaseBranch, pr.BaseRepo.OwnerName, pr.BaseRepo.Name, err)
+					return nil
+				}
+			}
+			pr.MergeBase = strings.TrimSpace(pr.MergeBase)
+			if pr.MergeBase != oldMergeBase {
+				if autofix {
+					if err := pr.UpdateCols(ctx, "merge_base"); err != nil {
+						logger.Critical("Failed to update merge_base. ERROR: %v", err)
+						return fmt.Errorf("Failed to update merge_base. ERROR: %w", err)
+					}
+				} else {
+					logger.Info("#%d onto %s in %s/%s: MergeBase should be %s but is %s", pr.Index, pr.BaseBranch, pr.BaseRepo.OwnerName, pr.BaseRepo.Name, oldMergeBase, pr.MergeBase)
+				}
+				numPRsUpdated++
+			}
+			return nil
+		})
+	})
+
+	if autofix {
+		logger.Info("%d PR mergebases updated of %d PRs total in %d repos", numPRsUpdated, numPRs, numRepos)
+	} else {
+		if numPRsUpdated == 0 {
+			logger.Info("All %d PRs in %d repos have a correct mergebase", numPRs, numRepos)
+		} else if err == nil {
+			logger.Critical("%d PRs with incorrect mergebases of %d PRs total in %d repos", numPRsUpdated, numPRs, numRepos)
+			return fmt.Errorf("%d PRs with incorrect mergebases of %d PRs total in %d repos", numPRsUpdated, numPRs, numRepos)
+		} else {
+			logger.Warn("%d PRs with incorrect mergebases of %d PRs total in %d repos", numPRsUpdated, numPRs, numRepos)
+		}
+	}
+
+	return err
+}
+
+func init() {
+	Register(&Check{
+		Title:     "Recalculate merge bases",
+		Name:      "recalculate-merge-bases",
+		IsDefault: false,
+		Run:       checkPRMergeBase,
+		Priority:  7,
+	})
+}