gitea/services/pull/merge.go
Chris Copeland 47b5965862
Add merge style fast-forward-only (#28954)
With this option, it is possible to require a linear commit history with
the following benefits over the next best option `Rebase+fast-forward`:
The original commits continue existing, with the original signatures
continuing to stay valid instead of being rewritten, there is no merge
commit, and reverting commits becomes easier.

Closes #24906
2024-02-12 23:37:23 +01:00

543 lines
18 KiB
Go

// Copyright 2019 The Gitea Authors.
// All rights reserved.
// SPDX-License-Identifier: MIT
package pull
import (
"context"
"fmt"
"os"
"path/filepath"
"regexp"
"strconv"
"strings"
"code.gitea.io/gitea/models"
"code.gitea.io/gitea/models/db"
git_model "code.gitea.io/gitea/models/git"
issues_model "code.gitea.io/gitea/models/issues"
access_model "code.gitea.io/gitea/models/perm/access"
pull_model "code.gitea.io/gitea/models/pull"
repo_model "code.gitea.io/gitea/models/repo"
"code.gitea.io/gitea/models/unit"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/cache"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/references"
repo_module "code.gitea.io/gitea/modules/repository"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/timeutil"
issue_service "code.gitea.io/gitea/services/issue"
notify_service "code.gitea.io/gitea/services/notify"
)
// getMergeMessage composes the message used when merging a pull request.
func getMergeMessage(ctx context.Context, baseGitRepo *git.Repository, pr *issues_model.PullRequest, mergeStyle repo_model.MergeStyle, extraVars map[string]string) (message, body string, err error) {
if err := pr.LoadBaseRepo(ctx); err != nil {
return "", "", err
}
if err := pr.LoadHeadRepo(ctx); err != nil {
return "", "", err
}
if err := pr.LoadIssue(ctx); err != nil {
return "", "", err
}
if err := pr.Issue.LoadPoster(ctx); err != nil {
return "", "", err
}
isExternalTracker := pr.BaseRepo.UnitEnabled(ctx, unit.TypeExternalTracker)
issueReference := "#"
if isExternalTracker {
issueReference = "!"
}
if mergeStyle != "" {
templateFilepath := fmt.Sprintf(".gitea/default_merge_message/%s_TEMPLATE.md", strings.ToUpper(string(mergeStyle)))
commit, err := baseGitRepo.GetBranchCommit(pr.BaseRepo.DefaultBranch)
if err != nil {
return "", "", err
}
templateContent, err := commit.GetFileContent(templateFilepath, setting.Repository.PullRequest.DefaultMergeMessageSize)
if err != nil {
if !git.IsErrNotExist(err) {
return "", "", err
}
} else {
vars := map[string]string{
"BaseRepoOwnerName": pr.BaseRepo.OwnerName,
"BaseRepoName": pr.BaseRepo.Name,
"BaseBranch": pr.BaseBranch,
"HeadRepoOwnerName": "",
"HeadRepoName": "",
"HeadBranch": pr.HeadBranch,
"PullRequestTitle": pr.Issue.Title,
"PullRequestDescription": pr.Issue.Content,
"PullRequestPosterName": pr.Issue.Poster.Name,
"PullRequestIndex": strconv.FormatInt(pr.Index, 10),
"PullRequestReference": fmt.Sprintf("%s%d", issueReference, pr.Index),
}
if pr.HeadRepo != nil {
vars["HeadRepoOwnerName"] = pr.HeadRepo.OwnerName
vars["HeadRepoName"] = pr.HeadRepo.Name
}
for extraKey, extraValue := range extraVars {
vars[extraKey] = extraValue
}
refs, err := pr.ResolveCrossReferences(ctx)
if err == nil {
closeIssueIndexes := make([]string, 0, len(refs))
closeWord := "close"
if len(setting.Repository.PullRequest.CloseKeywords) > 0 {
closeWord = setting.Repository.PullRequest.CloseKeywords[0]
}
for _, ref := range refs {
if ref.RefAction == references.XRefActionCloses {
if err := ref.LoadIssue(ctx); err != nil {
return "", "", err
}
closeIssueIndexes = append(closeIssueIndexes, fmt.Sprintf("%s %s%d", closeWord, issueReference, ref.Issue.Index))
}
}
if len(closeIssueIndexes) > 0 {
vars["ClosingIssues"] = strings.Join(closeIssueIndexes, ", ")
} else {
vars["ClosingIssues"] = ""
}
}
message, body = expandDefaultMergeMessage(templateContent, vars)
return message, body, nil
}
}
if mergeStyle == repo_model.MergeStyleRebase {
// for fast-forward rebase, do not amend the last commit if there is no template
return "", "", nil
}
// Squash merge has a different from other styles.
if mergeStyle == repo_model.MergeStyleSquash {
return fmt.Sprintf("%s (%s%d)", pr.Issue.Title, issueReference, pr.Issue.Index), "", nil
}
if pr.BaseRepoID == pr.HeadRepoID {
return fmt.Sprintf("Merge pull request '%s' (%s%d) from %s into %s", pr.Issue.Title, issueReference, pr.Issue.Index, pr.HeadBranch, pr.BaseBranch), "", nil
}
if pr.HeadRepo == nil {
return fmt.Sprintf("Merge pull request '%s' (%s%d) from <deleted>:%s into %s", pr.Issue.Title, issueReference, pr.Issue.Index, pr.HeadBranch, pr.BaseBranch), "", nil
}
return fmt.Sprintf("Merge pull request '%s' (%s%d) from %s:%s into %s", pr.Issue.Title, issueReference, pr.Issue.Index, pr.HeadRepo.FullName(), pr.HeadBranch, pr.BaseBranch), "", nil
}
func expandDefaultMergeMessage(template string, vars map[string]string) (message, body string) {
message = strings.TrimSpace(template)
if splits := strings.SplitN(message, "\n", 2); len(splits) == 2 {
message = splits[0]
body = strings.TrimSpace(splits[1])
}
mapping := func(s string) string { return vars[s] }
return os.Expand(message, mapping), os.Expand(body, mapping)
}
// GetDefaultMergeMessage returns default message used when merging pull request
func GetDefaultMergeMessage(ctx context.Context, baseGitRepo *git.Repository, pr *issues_model.PullRequest, mergeStyle repo_model.MergeStyle) (message, body string, err error) {
return getMergeMessage(ctx, baseGitRepo, pr, mergeStyle, nil)
}
// Merge merges pull request to base repository.
// Caller should check PR is ready to be merged (review and status checks)
func Merge(ctx context.Context, pr *issues_model.PullRequest, doer *user_model.User, baseGitRepo *git.Repository, mergeStyle repo_model.MergeStyle, expectedHeadCommitID, message string, wasAutoMerged bool) error {
if err := pr.LoadBaseRepo(ctx); err != nil {
log.Error("Unable to load base repo: %v", err)
return fmt.Errorf("unable to load base repo: %w", err)
} else if err := pr.LoadHeadRepo(ctx); err != nil {
log.Error("Unable to load head repo: %v", err)
return fmt.Errorf("unable to load head repo: %w", err)
}
pullWorkingPool.CheckIn(fmt.Sprint(pr.ID))
defer pullWorkingPool.CheckOut(fmt.Sprint(pr.ID))
// Removing an auto merge pull and ignore if not exist
// FIXME: is this the correct point to do this? Shouldn't this be after IsMergeStyleAllowed?
if err := pull_model.DeleteScheduledAutoMerge(ctx, pr.ID); err != nil && !db.IsErrNotExist(err) {
return err
}
prUnit, err := pr.BaseRepo.GetUnit(ctx, unit.TypePullRequests)
if err != nil {
log.Error("pr.BaseRepo.GetUnit(unit.TypePullRequests): %v", err)
return err
}
prConfig := prUnit.PullRequestsConfig()
// Check if merge style is correct and allowed
if !prConfig.IsMergeStyleAllowed(mergeStyle) {
return models.ErrInvalidMergeStyle{ID: pr.BaseRepo.ID, Style: mergeStyle}
}
defer func() {
go AddTestPullRequestTask(doer, pr.BaseRepo.ID, pr.BaseBranch, false, "", "")
}()
pr.MergedCommitID, err = doMergeAndPush(ctx, pr, doer, mergeStyle, expectedHeadCommitID, message)
if err != nil {
return err
}
pr.MergedUnix = timeutil.TimeStampNow()
pr.Merger = doer
pr.MergerID = doer.ID
if _, err := pr.SetMerged(ctx); err != nil {
log.Error("SetMerged %-v: %v", pr, err)
}
if err := pr.LoadIssue(ctx); err != nil {
log.Error("LoadIssue %-v: %v", pr, err)
}
if err := pr.Issue.LoadRepo(ctx); err != nil {
log.Error("pr.Issue.LoadRepo %-v: %v", pr, err)
}
if err := pr.Issue.Repo.LoadOwner(ctx); err != nil {
log.Error("LoadOwner for %-v: %v", pr, err)
}
if wasAutoMerged {
notify_service.AutoMergePullRequest(ctx, doer, pr)
} else {
notify_service.MergePullRequest(ctx, doer, pr)
}
// Reset cached commit count
cache.Remove(pr.Issue.Repo.GetCommitsCountCacheKey(pr.BaseBranch, true))
// Resolve cross references
refs, err := pr.ResolveCrossReferences(ctx)
if err != nil {
log.Error("ResolveCrossReferences: %v", err)
return nil
}
for _, ref := range refs {
if err = ref.LoadIssue(ctx); err != nil {
return err
}
if err = ref.Issue.LoadRepo(ctx); err != nil {
return err
}
close := ref.RefAction == references.XRefActionCloses
if close != ref.Issue.IsClosed {
if err = issue_service.ChangeStatus(ctx, ref.Issue, doer, pr.MergedCommitID, close); err != nil {
// Allow ErrDependenciesLeft
if !issues_model.IsErrDependenciesLeft(err) {
return err
}
}
}
}
return nil
}
// doMergeAndPush performs the merge operation without changing any pull information in database and pushes it up to the base repository
func doMergeAndPush(ctx context.Context, pr *issues_model.PullRequest, doer *user_model.User, mergeStyle repo_model.MergeStyle, expectedHeadCommitID, message string) (string, error) {
// Clone base repo.
mergeCtx, cancel, err := createTemporaryRepoForMerge(ctx, pr, doer, expectedHeadCommitID)
if err != nil {
return "", err
}
defer cancel()
// Merge commits.
switch mergeStyle {
case repo_model.MergeStyleMerge:
if err := doMergeStyleMerge(mergeCtx, message); err != nil {
return "", err
}
case repo_model.MergeStyleRebase, repo_model.MergeStyleRebaseMerge:
if err := doMergeStyleRebase(mergeCtx, mergeStyle, message); err != nil {
return "", err
}
case repo_model.MergeStyleSquash:
if err := doMergeStyleSquash(mergeCtx, message); err != nil {
return "", err
}
case repo_model.MergeStyleFastForwardOnly:
if err := doMergeStyleFastForwardOnly(mergeCtx); err != nil {
return "", err
}
default:
return "", models.ErrInvalidMergeStyle{ID: pr.BaseRepo.ID, Style: mergeStyle}
}
// OK we should cache our current head and origin/headbranch
mergeHeadSHA, err := git.GetFullCommitID(ctx, mergeCtx.tmpBasePath, "HEAD")
if err != nil {
return "", fmt.Errorf("Failed to get full commit id for HEAD: %w", err)
}
mergeBaseSHA, err := git.GetFullCommitID(ctx, mergeCtx.tmpBasePath, "original_"+baseBranch)
if err != nil {
return "", fmt.Errorf("Failed to get full commit id for origin/%s: %w", pr.BaseBranch, err)
}
mergeCommitID, err := git.GetFullCommitID(ctx, mergeCtx.tmpBasePath, baseBranch)
if err != nil {
return "", fmt.Errorf("Failed to get full commit id for the new merge: %w", err)
}
// Now it's questionable about where this should go - either after or before the push
// I think in the interests of data safety - failures to push to the lfs should prevent
// the merge as you can always remerge.
if setting.LFS.StartServer {
if err := LFSPush(ctx, mergeCtx.tmpBasePath, mergeHeadSHA, mergeBaseSHA, pr); err != nil {
return "", err
}
}
var headUser *user_model.User
err = pr.HeadRepo.LoadOwner(ctx)
if err != nil {
if !user_model.IsErrUserNotExist(err) {
log.Error("Can't find user: %d for head repository in %-v: %v", pr.HeadRepo.OwnerID, pr, err)
return "", err
}
log.Warn("Can't find user: %d for head repository in %-v - defaulting to doer: %s - %v", pr.HeadRepo.OwnerID, pr, doer.Name, err)
headUser = doer
} else {
headUser = pr.HeadRepo.Owner
}
mergeCtx.env = repo_module.FullPushingEnvironment(
headUser,
doer,
pr.BaseRepo,
pr.BaseRepo.Name,
pr.ID,
)
pushCmd := git.NewCommand(ctx, "push", "origin").AddDynamicArguments(baseBranch + ":" + git.BranchPrefix + pr.BaseBranch)
// Push back to upstream.
// TODO: this cause an api call to "/api/internal/hook/post-receive/...",
// that prevents us from doint the whole merge in one db transaction
if err := pushCmd.Run(mergeCtx.RunOpts()); err != nil {
if strings.Contains(mergeCtx.errbuf.String(), "non-fast-forward") {
return "", &git.ErrPushOutOfDate{
StdOut: mergeCtx.outbuf.String(),
StdErr: mergeCtx.errbuf.String(),
Err: err,
}
} else if strings.Contains(mergeCtx.errbuf.String(), "! [remote rejected]") {
err := &git.ErrPushRejected{
StdOut: mergeCtx.outbuf.String(),
StdErr: mergeCtx.errbuf.String(),
Err: err,
}
err.GenerateMessage()
return "", err
}
return "", fmt.Errorf("git push: %s", mergeCtx.errbuf.String())
}
mergeCtx.outbuf.Reset()
mergeCtx.errbuf.Reset()
return mergeCommitID, nil
}
func commitAndSignNoAuthor(ctx *mergeContext, message string) error {
cmdCommit := git.NewCommand(ctx, "commit").AddOptionFormat("--message=%s", message)
if ctx.signKeyID == "" {
cmdCommit.AddArguments("--no-gpg-sign")
} else {
cmdCommit.AddOptionFormat("-S%s", ctx.signKeyID)
}
if err := cmdCommit.Run(ctx.RunOpts()); err != nil {
log.Error("git commit %-v: %v\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
return fmt.Errorf("git commit %v: %w\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
}
return nil
}
func runMergeCommand(ctx *mergeContext, mergeStyle repo_model.MergeStyle, cmd *git.Command) error {
if err := cmd.Run(ctx.RunOpts()); err != nil {
// Merge will leave a MERGE_HEAD file in the .git folder if there is a conflict
if _, statErr := os.Stat(filepath.Join(ctx.tmpBasePath, ".git", "MERGE_HEAD")); statErr == nil {
// We have a merge conflict error
log.Debug("MergeConflict %-v: %v\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
return models.ErrMergeConflicts{
Style: mergeStyle,
StdOut: ctx.outbuf.String(),
StdErr: ctx.errbuf.String(),
Err: err,
}
} else if strings.Contains(ctx.errbuf.String(), "refusing to merge unrelated histories") {
log.Debug("MergeUnrelatedHistories %-v: %v\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
return models.ErrMergeUnrelatedHistories{
Style: mergeStyle,
StdOut: ctx.outbuf.String(),
StdErr: ctx.errbuf.String(),
Err: err,
}
} else if mergeStyle == repo_model.MergeStyleFastForwardOnly && strings.Contains(ctx.errbuf.String(), "Not possible to fast-forward, aborting") {
log.Debug("MergeDivergingFastForwardOnly %-v: %v\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
return models.ErrMergeDivergingFastForwardOnly{
StdOut: ctx.outbuf.String(),
StdErr: ctx.errbuf.String(),
Err: err,
}
}
log.Error("git merge %-v: %v\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
return fmt.Errorf("git merge %v: %w\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
}
ctx.outbuf.Reset()
ctx.errbuf.Reset()
return nil
}
var escapedSymbols = regexp.MustCompile(`([*[?! \\])`)
// IsUserAllowedToMerge check if user is allowed to merge PR with given permissions and branch protections
func IsUserAllowedToMerge(ctx context.Context, pr *issues_model.PullRequest, p access_model.Permission, user *user_model.User) (bool, error) {
if user == nil {
return false, nil
}
pb, err := git_model.GetFirstMatchProtectedBranchRule(ctx, pr.BaseRepoID, pr.BaseBranch)
if err != nil {
return false, err
}
if (p.CanWrite(unit.TypeCode) && pb == nil) || (pb != nil && git_model.IsUserMergeWhitelisted(ctx, pb, user.ID, p)) {
return true, nil
}
return false, nil
}
// CheckPullBranchProtections checks whether the PR is ready to be merged (reviews and status checks)
func CheckPullBranchProtections(ctx context.Context, pr *issues_model.PullRequest, skipProtectedFilesCheck bool) (err error) {
if err = pr.LoadBaseRepo(ctx); err != nil {
return fmt.Errorf("LoadBaseRepo: %w", err)
}
pb, err := git_model.GetFirstMatchProtectedBranchRule(ctx, pr.BaseRepoID, pr.BaseBranch)
if err != nil {
return fmt.Errorf("LoadProtectedBranch: %v", err)
}
if pb == nil {
return nil
}
isPass, err := IsPullCommitStatusPass(ctx, pr)
if err != nil {
return err
}
if !isPass {
return models.ErrDisallowedToMerge{
Reason: "Not all required status checks successful",
}
}
if !issues_model.HasEnoughApprovals(ctx, pb, pr) {
return models.ErrDisallowedToMerge{
Reason: "Does not have enough approvals",
}
}
if issues_model.MergeBlockedByRejectedReview(ctx, pb, pr) {
return models.ErrDisallowedToMerge{
Reason: "There are requested changes",
}
}
if issues_model.MergeBlockedByOfficialReviewRequests(ctx, pb, pr) {
return models.ErrDisallowedToMerge{
Reason: "There are official review requests",
}
}
if issues_model.MergeBlockedByOutdatedBranch(pb, pr) {
return models.ErrDisallowedToMerge{
Reason: "The head branch is behind the base branch",
}
}
if skipProtectedFilesCheck {
return nil
}
if pb.MergeBlockedByProtectedFiles(pr.ChangedProtectedFiles) {
return models.ErrDisallowedToMerge{
Reason: "Changed protected files",
}
}
return nil
}
// MergedManually mark pr as merged manually
func MergedManually(ctx context.Context, pr *issues_model.PullRequest, doer *user_model.User, baseGitRepo *git.Repository, commitID string) error {
pullWorkingPool.CheckIn(fmt.Sprint(pr.ID))
defer pullWorkingPool.CheckOut(fmt.Sprint(pr.ID))
if err := db.WithTx(ctx, func(ctx context.Context) error {
if err := pr.LoadBaseRepo(ctx); err != nil {
return err
}
prUnit, err := pr.BaseRepo.GetUnit(ctx, unit.TypePullRequests)
if err != nil {
return err
}
prConfig := prUnit.PullRequestsConfig()
// Check if merge style is correct and allowed
if !prConfig.IsMergeStyleAllowed(repo_model.MergeStyleManuallyMerged) {
return models.ErrInvalidMergeStyle{ID: pr.BaseRepo.ID, Style: repo_model.MergeStyleManuallyMerged}
}
objectFormat, _ := baseGitRepo.GetObjectFormat()
if len(commitID) != objectFormat.FullLength() {
return fmt.Errorf("Wrong commit ID")
}
commit, err := baseGitRepo.GetCommit(commitID)
if err != nil {
if git.IsErrNotExist(err) {
return fmt.Errorf("Wrong commit ID")
}
return err
}
commitID = commit.ID.String()
ok, err := baseGitRepo.IsCommitInBranch(commitID, pr.BaseBranch)
if err != nil {
return err
}
if !ok {
return fmt.Errorf("Wrong commit ID")
}
pr.MergedCommitID = commitID
pr.MergedUnix = timeutil.TimeStamp(commit.Author.When.Unix())
pr.Status = issues_model.PullRequestStatusManuallyMerged
pr.Merger = doer
pr.MergerID = doer.ID
var merged bool
if merged, err = pr.SetMerged(ctx); err != nil {
return err
} else if !merged {
return fmt.Errorf("SetMerged failed")
}
return nil
}); err != nil {
return err
}
notify_service.MergePullRequest(baseGitRepo.Ctx, doer, pr)
log.Info("manuallyMerged[%d]: Marked as manually merged into %s/%s by commit id: %s", pr.ID, pr.BaseRepo.Name, pr.BaseBranch, commitID)
return nil
}