1 files changed, 127 insertions, 0 deletions
diff --git a/models/migrations/v1_12/v128.go b/models/migrations/v1_12/v128.go
new file mode 100644
index 00000000..6eea1337
--- /dev/null
+++ b/models/migrations/v1_12/v128.go
@@ -0,0 +1,127 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_12 //nolint
+
+import (
+	"fmt"
+	"math"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+
+	"xorm.io/xorm"
+)
+
+func FixMergeBase(x *xorm.Engine) error {
+	type Repository struct {
+		ID        int64 `xorm:"pk autoincr"`
+		OwnerID   int64 `xorm:"UNIQUE(s) index"`
+		OwnerName string
+		LowerName string `xorm:"UNIQUE(s) INDEX NOT NULL"`
+		Name      string `xorm:"INDEX NOT NULL"`
+	}
+
+	type PullRequest struct {
+		ID         int64 `xorm:"pk autoincr"`
+		Index      int64
+		HeadRepoID int64 `xorm:"INDEX"`
+		BaseRepoID int64 `xorm:"INDEX"`
+		HeadBranch string
+		BaseBranch string
+		MergeBase  string `xorm:"VARCHAR(40)"`
+
+		HasMerged      bool   `xorm:"INDEX"`
+		MergedCommitID string `xorm:"VARCHAR(40)"`
+	}
+
+	limit := setting.Database.IterateBufferSize
+	if limit <= 0 {
+		limit = 50
+	}
+
+	ticker := time.NewTicker(5 * time.Second)
+	defer ticker.Stop()
+
+	count, err := x.Count(new(PullRequest))
+	if err != nil {
+		return err
+	}
+	log.Info("%d Pull Request(s) to migrate ...", count)
+
+	i := 0
+	start := 0
+	for {
+		prs := make([]PullRequest, 0, 50)
+		if err := x.Limit(limit, start).Asc("id").Find(&prs); err != nil {
+			return fmt.Errorf("Find: %w", err)
+		}
+		if len(prs) == 0 {
+			break
+		}
+
+		start += 50
+		for _, pr := range prs {
+			baseRepo := &Repository{ID: pr.BaseRepoID}
+			has, err := x.Table("repository").Get(baseRepo)
+			if err != nil {
+				return fmt.Errorf("Unable to get base repo %d %w", pr.BaseRepoID, err)
+			}
+			if !has {
+				log.Error("Missing base repo with id %d for PR ID %d", pr.BaseRepoID, pr.ID)
+				continue
+			}
+			userPath := filepath.Join(setting.RepoRootPath, strings.ToLower(baseRepo.OwnerName))
+			repoPath := filepath.Join(userPath, strings.ToLower(baseRepo.Name)+".git")
+
+			gitRefName := fmt.Sprintf("refs/pull/%d/head", pr.Index)
+
+			if !pr.HasMerged {
+				var err error
+				pr.MergeBase, _, err = git.NewCommand(git.DefaultContext, "merge-base").AddDashesAndList(pr.BaseBranch, gitRefName).RunStdString(&git.RunOpts{Dir: repoPath})
+				if err != nil {
+					var err2 error
+					pr.MergeBase, _, err2 = git.NewCommand(git.DefaultContext, "rev-parse").AddDynamicArguments(git.BranchPrefix + pr.BaseBranch).RunStdString(&git.RunOpts{Dir: repoPath})
+					if err2 != nil {
+						log.Error("Unable to get merge base for PR ID %d, Index %d in %s/%s. Error: %v & %v", pr.ID, pr.Index, baseRepo.OwnerName, baseRepo.Name, err, err2)
+						continue
+					}
+				}
+			} else {
+				parentsString, _, err := git.NewCommand(git.DefaultContext, "rev-list", "--parents", "-n", "1").AddDynamicArguments(pr.MergedCommitID).RunStdString(&git.RunOpts{Dir: repoPath})
+				if err != nil {
+					log.Warn("Unable to get parents for merged PR ID %d, Index %d in %s/%s. Error: %v", pr.ID, pr.Index, baseRepo.OwnerName, baseRepo.Name, err)
+					continue
+				}
+				parents := strings.Split(strings.TrimSpace(parentsString), " ")
+				if len(parents) < 2 {
+					continue
+				}
+
+				refs := append([]string{}, parents[1:]...)
+				refs = append(refs, gitRefName)
+				cmd := git.NewCommand(git.DefaultContext, "merge-base").AddDashesAndList(refs...)
+
+				pr.MergeBase, _, err = cmd.RunStdString(&git.RunOpts{Dir: repoPath})
+				if err != nil {
+					log.Error("Unable to get merge base for merged PR ID %d, Index %d in %s/%s. Error: %v", pr.ID, pr.Index, baseRepo.OwnerName, baseRepo.Name, err)
+					continue
+				}
+			}
+			pr.MergeBase = strings.TrimSpace(pr.MergeBase)
+			x.ID(pr.ID).Cols("merge_base").Update(pr)
+			i++
+			select {
+			case <-ticker.C:
+				log.Info("%d/%d (%2.0f%%) Pull Request(s) migrated in %d batches. %d PRs Remaining ...", i, count, float64(i)/float64(count)*100, int(math.Ceil(float64(i)/float64(limit))), count-int64(i))
+			default:
+			}
+		}
+	}
+	log.Info("Completed migrating %d Pull Request(s) in: %d batches", count, int(math.Ceil(float64(i)/float64(limit))))
+	return nil
+}