92e81e97e8
* Detect conflicts with 3way merge Unforunately git apply --3way reports conflicts differently than standard patches resulting in conflicts being missed. Adjust the conflict detection code to account for this different error reporting. Fix #18514 Signed-off-by: Andrew Thornton <art27@cantab.net> * and three-way failed Signed-off-by: Andrew Thornton <art27@cantab.net> Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
523 lines
17 KiB
Go
523 lines
17 KiB
Go
// Copyright 2019 The Gitea Authors.
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// All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package pull
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import (
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"bufio"
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"context"
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"fmt"
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"io"
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"os"
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"path/filepath"
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"strings"
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"code.gitea.io/gitea/models"
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"code.gitea.io/gitea/models/unit"
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"code.gitea.io/gitea/modules/git"
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"code.gitea.io/gitea/modules/graceful"
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"code.gitea.io/gitea/modules/log"
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"code.gitea.io/gitea/modules/process"
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"code.gitea.io/gitea/modules/util"
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"github.com/gobwas/glob"
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)
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// DownloadDiffOrPatch will write the patch for the pr to the writer
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func DownloadDiffOrPatch(ctx context.Context, pr *models.PullRequest, w io.Writer, patch, binary bool) error {
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if err := pr.LoadBaseRepo(); err != nil {
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log.Error("Unable to load base repository ID %d for pr #%d [%d]", pr.BaseRepoID, pr.Index, pr.ID)
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return err
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}
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gitRepo, closer, err := git.RepositoryFromContextOrOpen(ctx, pr.BaseRepo.RepoPath())
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if err != nil {
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return fmt.Errorf("OpenRepository: %v", err)
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}
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defer closer.Close()
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if err := gitRepo.GetDiffOrPatch(pr.MergeBase, pr.GetGitRefName(), w, patch, binary); err != nil {
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log.Error("Unable to get patch file from %s to %s in %s Error: %v", pr.MergeBase, pr.HeadBranch, pr.BaseRepo.FullName(), err)
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return fmt.Errorf("Unable to get patch file from %s to %s in %s Error: %v", pr.MergeBase, pr.HeadBranch, pr.BaseRepo.FullName(), err)
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}
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return nil
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}
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var patchErrorSuffices = []string{
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": already exists in index",
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": patch does not apply",
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": already exists in working directory",
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"unrecognized input",
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}
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// TestPatch will test whether a simple patch will apply
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func TestPatch(pr *models.PullRequest) error {
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ctx, _, finished := process.GetManager().AddContext(graceful.GetManager().HammerContext(), fmt.Sprintf("TestPatch: Repo[%d]#%d", pr.BaseRepoID, pr.Index))
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defer finished()
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// Clone base repo.
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tmpBasePath, err := createTemporaryRepo(ctx, pr)
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if err != nil {
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log.Error("CreateTemporaryPath: %v", err)
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return err
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}
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defer func() {
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if err := models.RemoveTemporaryPath(tmpBasePath); err != nil {
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log.Error("Merge: RemoveTemporaryPath: %s", err)
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}
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}()
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gitRepo, err := git.OpenRepositoryCtx(ctx, tmpBasePath)
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if err != nil {
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return fmt.Errorf("OpenRepository: %v", err)
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}
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defer gitRepo.Close()
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// 1. update merge base
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pr.MergeBase, err = git.NewCommandContext(ctx, "merge-base", "--", "base", "tracking").RunInDir(tmpBasePath)
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if err != nil {
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var err2 error
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pr.MergeBase, err2 = gitRepo.GetRefCommitID(git.BranchPrefix + "base")
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if err2 != nil {
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return fmt.Errorf("GetMergeBase: %v and can't find commit ID for base: %v", err, err2)
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}
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}
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pr.MergeBase = strings.TrimSpace(pr.MergeBase)
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// 2. Check for conflicts
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if conflicts, err := checkConflicts(pr, gitRepo, tmpBasePath); err != nil || conflicts || pr.Status == models.PullRequestStatusEmpty {
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return err
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}
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// 3. Check for protected files changes
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if err = checkPullFilesProtection(pr, gitRepo); err != nil {
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return fmt.Errorf("pr.CheckPullFilesProtection(): %v", err)
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}
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if len(pr.ChangedProtectedFiles) > 0 {
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log.Trace("Found %d protected files changed", len(pr.ChangedProtectedFiles))
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}
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pr.Status = models.PullRequestStatusMergeable
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return nil
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}
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type errMergeConflict struct {
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filename string
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}
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func (e *errMergeConflict) Error() string {
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return fmt.Sprintf("conflict detected at: %s", e.filename)
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}
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func attemptMerge(ctx context.Context, file *unmergedFile, tmpBasePath string, gitRepo *git.Repository) error {
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switch {
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case file.stage1 != nil && (file.stage2 == nil || file.stage3 == nil):
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// 1. Deleted in one or both:
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//
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// Conflict <==> the stage1 !SameAs to the undeleted one
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if (file.stage2 != nil && !file.stage1.SameAs(file.stage2)) || (file.stage3 != nil && !file.stage1.SameAs(file.stage3)) {
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// Conflict!
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return &errMergeConflict{file.stage1.path}
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}
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// Not a genuine conflict and we can simply remove the file from the index
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return gitRepo.RemoveFilesFromIndex(file.stage1.path)
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case file.stage1 == nil && file.stage2 != nil && (file.stage3 == nil || file.stage2.SameAs(file.stage3)):
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// 2. Added in ours but not in theirs or identical in both
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//
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// Not a genuine conflict just add to the index
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if err := gitRepo.AddObjectToIndex(file.stage2.mode, git.MustIDFromString(file.stage2.sha), file.stage2.path); err != nil {
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return err
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}
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return nil
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case file.stage1 == nil && file.stage2 != nil && file.stage3 != nil && file.stage2.sha == file.stage3.sha && file.stage2.mode != file.stage3.mode:
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// 3. Added in both with the same sha but the modes are different
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//
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// Conflict! (Not sure that this can actually happen but we should handle)
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return &errMergeConflict{file.stage2.path}
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case file.stage1 == nil && file.stage2 == nil && file.stage3 != nil:
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// 4. Added in theirs but not ours:
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//
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// Not a genuine conflict just add to the index
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return gitRepo.AddObjectToIndex(file.stage3.mode, git.MustIDFromString(file.stage3.sha), file.stage3.path)
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case file.stage1 == nil:
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// 5. Created by new in both
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//
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// Conflict!
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return &errMergeConflict{file.stage2.path}
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case file.stage2 != nil && file.stage3 != nil:
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// 5. Modified in both - we should try to merge in the changes but first:
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//
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if file.stage2.mode == "120000" || file.stage3.mode == "120000" {
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// 5a. Conflicting symbolic link change
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return &errMergeConflict{file.stage2.path}
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}
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if file.stage2.mode == "160000" || file.stage3.mode == "160000" {
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// 5b. Conflicting submodule change
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return &errMergeConflict{file.stage2.path}
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}
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if file.stage2.mode != file.stage3.mode {
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// 5c. Conflicting mode change
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return &errMergeConflict{file.stage2.path}
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}
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// Need to get the objects from the object db to attempt to merge
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root, err := git.NewCommandContext(ctx, "unpack-file", file.stage1.sha).RunInDir(tmpBasePath)
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if err != nil {
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return fmt.Errorf("unable to get root object: %s at path: %s for merging. Error: %w", file.stage1.sha, file.stage1.path, err)
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}
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root = strings.TrimSpace(root)
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defer func() {
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_ = util.Remove(filepath.Join(tmpBasePath, root))
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}()
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base, err := git.NewCommandContext(ctx, "unpack-file", file.stage2.sha).RunInDir(tmpBasePath)
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if err != nil {
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return fmt.Errorf("unable to get base object: %s at path: %s for merging. Error: %w", file.stage2.sha, file.stage2.path, err)
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}
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base = strings.TrimSpace(filepath.Join(tmpBasePath, base))
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defer func() {
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_ = util.Remove(base)
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}()
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head, err := git.NewCommandContext(ctx, "unpack-file", file.stage3.sha).RunInDir(tmpBasePath)
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if err != nil {
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return fmt.Errorf("unable to get head object:%s at path: %s for merging. Error: %w", file.stage3.sha, file.stage3.path, err)
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}
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head = strings.TrimSpace(head)
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defer func() {
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_ = util.Remove(filepath.Join(tmpBasePath, head))
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}()
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// now git merge-file annoyingly takes a different order to the merge-tree ...
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_, conflictErr := git.NewCommandContext(ctx, "merge-file", base, root, head).RunInDir(tmpBasePath)
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if conflictErr != nil {
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return &errMergeConflict{file.stage2.path}
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}
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// base now contains the merged data
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hash, err := git.NewCommandContext(ctx, "hash-object", "-w", "--path", file.stage2.path, base).RunInDir(tmpBasePath)
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if err != nil {
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return err
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}
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hash = strings.TrimSpace(hash)
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return gitRepo.AddObjectToIndex(file.stage2.mode, git.MustIDFromString(hash), file.stage2.path)
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default:
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if file.stage1 != nil {
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return &errMergeConflict{file.stage1.path}
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} else if file.stage2 != nil {
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return &errMergeConflict{file.stage2.path}
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} else if file.stage3 != nil {
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return &errMergeConflict{file.stage3.path}
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}
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}
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return nil
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}
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func checkConflicts(pr *models.PullRequest, gitRepo *git.Repository, tmpBasePath string) (bool, error) {
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ctx, cancel, finished := process.GetManager().AddContext(graceful.GetManager().HammerContext(), fmt.Sprintf("checkConflicts: pr[%d] %s/%s#%d", pr.ID, pr.BaseRepo.OwnerName, pr.BaseRepo.Name, pr.Index))
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defer finished()
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// First we use read-tree to do a simple three-way merge
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if _, err := git.NewCommandContext(ctx, "read-tree", "-m", pr.MergeBase, "base", "tracking").RunInDir(tmpBasePath); err != nil {
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log.Error("Unable to run read-tree -m! Error: %v", err)
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return false, fmt.Errorf("unable to run read-tree -m! Error: %v", err)
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}
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// Then we use git ls-files -u to list the unmerged files and collate the triples in unmergedfiles
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unmerged := make(chan *unmergedFile)
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go unmergedFiles(ctx, tmpBasePath, unmerged)
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defer func() {
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cancel()
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for range unmerged {
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// empty the unmerged channel
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}
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}()
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numberOfConflicts := 0
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pr.ConflictedFiles = make([]string, 0, 5)
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conflict := false
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for file := range unmerged {
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if file == nil {
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break
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}
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if file.err != nil {
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cancel()
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return false, file.err
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}
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// OK now we have the unmerged file triplet attempt to merge it
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if err := attemptMerge(ctx, file, tmpBasePath, gitRepo); err != nil {
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if conflictErr, ok := err.(*errMergeConflict); ok {
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log.Trace("Conflict: %s in PR[%d] %s/%s#%d", conflictErr.filename, pr.ID, pr.BaseRepo.OwnerName, pr.BaseRepo.Name, pr.Index)
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conflict = true
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if numberOfConflicts < 10 {
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pr.ConflictedFiles = append(pr.ConflictedFiles, conflictErr.filename)
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}
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numberOfConflicts++
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continue
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}
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return false, err
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}
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}
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if !conflict {
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treeHash, err := git.NewCommandContext(ctx, "write-tree").RunInDir(tmpBasePath)
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if err != nil {
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return false, err
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}
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treeHash = strings.TrimSpace(treeHash)
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baseTree, err := gitRepo.GetTree("base")
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if err != nil {
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return false, err
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}
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if treeHash == baseTree.ID.String() {
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log.Debug("PullRequest[%d]: Patch is empty - ignoring", pr.ID)
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pr.Status = models.PullRequestStatusEmpty
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pr.ConflictedFiles = []string{}
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pr.ChangedProtectedFiles = []string{}
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}
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return false, nil
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}
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// OK read-tree has failed so we need to try a different thing - this might actually succeed where the above fails due to whitespace handling.
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// 1. Create a plain patch from head to base
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tmpPatchFile, err := os.CreateTemp("", "patch")
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if err != nil {
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log.Error("Unable to create temporary patch file! Error: %v", err)
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return false, fmt.Errorf("unable to create temporary patch file! Error: %v", err)
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}
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defer func() {
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_ = util.Remove(tmpPatchFile.Name())
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}()
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if err := gitRepo.GetDiffBinary(pr.MergeBase, "tracking", tmpPatchFile); err != nil {
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tmpPatchFile.Close()
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log.Error("Unable to get patch file from %s to %s in %s Error: %v", pr.MergeBase, pr.HeadBranch, pr.BaseRepo.FullName(), err)
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return false, fmt.Errorf("unable to get patch file from %s to %s in %s Error: %v", pr.MergeBase, pr.HeadBranch, pr.BaseRepo.FullName(), err)
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}
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stat, err := tmpPatchFile.Stat()
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if err != nil {
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tmpPatchFile.Close()
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return false, fmt.Errorf("unable to stat patch file: %v", err)
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}
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patchPath := tmpPatchFile.Name()
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tmpPatchFile.Close()
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// 1a. if the size of that patch is 0 - there can be no conflicts!
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if stat.Size() == 0 {
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log.Debug("PullRequest[%d]: Patch is empty - ignoring", pr.ID)
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pr.Status = models.PullRequestStatusEmpty
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pr.ConflictedFiles = []string{}
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pr.ChangedProtectedFiles = []string{}
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return false, nil
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}
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log.Trace("PullRequest[%d].testPatch (patchPath): %s", pr.ID, patchPath)
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// 2. preset the pr.Status as checking (this is not save at present)
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pr.Status = models.PullRequestStatusChecking
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// 3. Read the base branch in to the index of the temporary repository
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_, err = git.NewCommandContext(gitRepo.Ctx, "read-tree", "base").RunInDir(tmpBasePath)
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if err != nil {
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return false, fmt.Errorf("git read-tree %s: %v", pr.BaseBranch, err)
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}
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// 4. Now get the pull request configuration to check if we need to ignore whitespace
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prUnit, err := pr.BaseRepo.GetUnit(unit.TypePullRequests)
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if err != nil {
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return false, err
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}
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prConfig := prUnit.PullRequestsConfig()
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// 5. Prepare the arguments to apply the patch against the index
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args := []string{"apply", "--check", "--cached"}
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if prConfig.IgnoreWhitespaceConflicts {
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args = append(args, "--ignore-whitespace")
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}
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is3way := false
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if git.CheckGitVersionAtLeast("2.32.0") == nil {
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args = append(args, "--3way")
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is3way = true
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}
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args = append(args, patchPath)
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pr.ConflictedFiles = make([]string, 0, 5)
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// 6. Prep the pipe:
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// - Here we could do the equivalent of:
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// `git apply --check --cached patch_file > conflicts`
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// Then iterate through the conflicts. However, that means storing all the conflicts
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// in memory - which is very wasteful.
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// - alternatively we can do the equivalent of:
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// `git apply --check ... | grep ...`
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// meaning we don't store all of the conflicts unnecessarily.
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stderrReader, stderrWriter, err := os.Pipe()
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if err != nil {
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log.Error("Unable to open stderr pipe: %v", err)
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return false, fmt.Errorf("unable to open stderr pipe: %v", err)
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}
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defer func() {
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_ = stderrReader.Close()
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_ = stderrWriter.Close()
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}()
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// 7. Run the check command
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conflict = false
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err = git.NewCommandContext(gitRepo.Ctx, args...).
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RunInDirTimeoutEnvFullPipelineFunc(
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nil, -1, tmpBasePath,
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nil, stderrWriter, nil,
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func(ctx context.Context, cancel context.CancelFunc) error {
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// Close the writer end of the pipe to begin processing
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_ = stderrWriter.Close()
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defer func() {
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// Close the reader on return to terminate the git command if necessary
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_ = stderrReader.Close()
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}()
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const prefix = "error: patch failed:"
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const errorPrefix = "error: "
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const threewayFailed = "Failed to perform three-way merge..."
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const appliedPatchPrefix = "Applied patch to '"
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const withConflicts = "' with conflicts."
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conflictMap := map[string]bool{}
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// Now scan the output from the command
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scanner := bufio.NewScanner(stderrReader)
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for scanner.Scan() {
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line := scanner.Text()
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if strings.HasPrefix(line, prefix) {
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conflict = true
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filepath := strings.TrimSpace(strings.Split(line[len(prefix):], ":")[0])
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conflictMap[filepath] = true
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} else if is3way && line == threewayFailed {
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conflict = true
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} else if strings.HasPrefix(line, errorPrefix) {
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conflict = true
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for _, suffix := range patchErrorSuffices {
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if strings.HasSuffix(line, suffix) {
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filepath := strings.TrimSpace(strings.TrimSuffix(line[len(errorPrefix):], suffix))
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if filepath != "" {
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conflictMap[filepath] = true
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}
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break
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}
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}
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} else if is3way && strings.HasPrefix(line, appliedPatchPrefix) && strings.HasSuffix(line, withConflicts) {
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conflict = true
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filepath := strings.TrimPrefix(strings.TrimSuffix(line, withConflicts), appliedPatchPrefix)
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if filepath != "" {
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conflictMap[filepath] = true
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}
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}
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// only list 10 conflicted files
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if len(conflictMap) >= 10 {
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break
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}
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}
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if len(conflictMap) > 0 {
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pr.ConflictedFiles = make([]string, 0, len(conflictMap))
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for key := range conflictMap {
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pr.ConflictedFiles = append(pr.ConflictedFiles, key)
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}
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}
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return nil
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})
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// 8. If there is a conflict the `git apply` command will return a non-zero error code - so there will be a positive error.
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if err != nil {
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if conflict {
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pr.Status = models.PullRequestStatusConflict
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log.Trace("Found %d files conflicted: %v", len(pr.ConflictedFiles), pr.ConflictedFiles)
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return true, nil
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}
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return false, fmt.Errorf("git apply --check: %v", err)
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}
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return false, nil
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}
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// CheckFileProtection check file Protection
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func CheckFileProtection(repo *git.Repository, oldCommitID, newCommitID string, patterns []glob.Glob, limit int, env []string) ([]string, error) {
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if len(patterns) == 0 {
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return nil, nil
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}
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affectedFiles, err := git.GetAffectedFiles(repo, oldCommitID, newCommitID, env)
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if err != nil {
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return nil, err
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|
}
|
|
changedProtectedFiles := make([]string, 0, limit)
|
|
for _, affectedFile := range affectedFiles {
|
|
lpath := strings.ToLower(affectedFile)
|
|
for _, pat := range patterns {
|
|
if pat.Match(lpath) {
|
|
changedProtectedFiles = append(changedProtectedFiles, lpath)
|
|
break
|
|
}
|
|
}
|
|
if len(changedProtectedFiles) >= limit {
|
|
break
|
|
}
|
|
}
|
|
if len(changedProtectedFiles) > 0 {
|
|
err = models.ErrFilePathProtected{
|
|
Path: changedProtectedFiles[0],
|
|
}
|
|
}
|
|
return changedProtectedFiles, err
|
|
}
|
|
|
|
// CheckUnprotectedFiles check if the commit only touches unprotected files
|
|
func CheckUnprotectedFiles(repo *git.Repository, oldCommitID, newCommitID string, patterns []glob.Glob, env []string) (bool, error) {
|
|
if len(patterns) == 0 {
|
|
return false, nil
|
|
}
|
|
affectedFiles, err := git.GetAffectedFiles(repo, oldCommitID, newCommitID, env)
|
|
if err != nil {
|
|
return false, err
|
|
}
|
|
for _, affectedFile := range affectedFiles {
|
|
lpath := strings.ToLower(affectedFile)
|
|
unprotected := false
|
|
for _, pat := range patterns {
|
|
if pat.Match(lpath) {
|
|
unprotected = true
|
|
break
|
|
}
|
|
}
|
|
if !unprotected {
|
|
return false, nil
|
|
}
|
|
}
|
|
return true, nil
|
|
}
|
|
|
|
// checkPullFilesProtection check if pr changed protected files and save results
|
|
func checkPullFilesProtection(pr *models.PullRequest, gitRepo *git.Repository) error {
|
|
if err := pr.LoadProtectedBranch(); err != nil {
|
|
return err
|
|
}
|
|
|
|
if pr.ProtectedBranch == nil {
|
|
pr.ChangedProtectedFiles = nil
|
|
return nil
|
|
}
|
|
|
|
var err error
|
|
pr.ChangedProtectedFiles, err = CheckFileProtection(gitRepo, pr.MergeBase, "tracking", pr.ProtectedBranch.GetProtectedFilePatterns(), 10, os.Environ())
|
|
if err != nil && !models.IsErrFilePathProtected(err) {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|