fix: hook post-receive for sha256 repos

cmd/hook.go

···
 		return nil
 	}
 
-	// Deletion of the ref means that the new commit ID is only composed of '0'.
-	if strings.ContainsFunc(newCommitID, func(e rune) bool { return e != '0' }) {
-		return nil
+	// Empty new commit ID means deletion.
+	if git.IsEmptyCommitID(newCommitID, nil) {
+		return fail(ctx, fmt.Sprintf("The deletion of %s is skipped as it's an internal reference.", refFullName), "")
 	}
 
-	return fail(ctx, fmt.Sprintf("The deletion of %s is skipped as it's an internal reference.", refFullName), "")
+	return nil
 }
 
 func runHookPostReceive(c *cli.Context) error {
···
 		newCommitIDs[count] = string(fields[1])
 		refFullNames[count] = git.RefName(fields[2])
 
-		commitID, _ := git.NewIDFromString(newCommitIDs[count])
-		if refFullNames[count] == git.BranchPrefix+"master" && !commitID.IsZero() && count == total {
+		if refFullNames[count] == git.BranchPrefix+"master" && !git.IsEmptyCommitID(newCommitIDs[count], nil) && count == total {
 			masterPushed = true
 		}
 		count++
···
 		if err != nil {
 			return err
 		}
-		commitID, _ := git.NewIDFromString(rs.OldOID)
-		if !commitID.IsZero() {
+		if !git.IsEmptyCommitID(rs.OldOID, nil) {
 			err = writeDataPktLine(ctx, os.Stdout, []byte("option old-oid "+rs.OldOID))
 			if err != nil {
 				return err

models/repo/repo.go

···
 // CommitLink make link to by commit full ID
 // note: won't check whether it's an right id
 func (repo *Repository) CommitLink(commitID string) (result string) {
-	if git.IsEmptyCommitID(commitID) {
+	if git.IsEmptyCommitID(commitID, nil) {
 		result = ""
 	} else {
 		result = repo.Link() + "/commit/" + url.PathEscape(commitID)

modules/git/object_format.go

···
 var (
 	Sha1ObjectFormat   ObjectFormat = Sha1ObjectFormatImpl{}
 	Sha256ObjectFormat ObjectFormat = Sha256ObjectFormatImpl{}
+	// any addition must be reflected in IsEmptyCommitID
 )
 
 var SupportedObjectFormats = []ObjectFormat{

modules/git/object_id.go

···
 	return theObjectFormat.MustID(b), nil
 }
 
-func IsEmptyCommitID(commitID string) bool {
+// IsEmptyCommitID checks if an hexadecimal string represents an empty commit according to git (only '0').
+// If objectFormat is not nil, the length will be checked as well (otherwise the lenght must match the sha1 or sha256 length).
+func IsEmptyCommitID(commitID string, objectFormat ObjectFormat) bool {
 	if commitID == "" {
 		return true
 	}
-
-	id, err := NewIDFromString(commitID)
-	if err != nil {
+	if objectFormat == nil {
+		if Sha1ObjectFormat.FullLength() != len(commitID) && Sha256ObjectFormat.FullLength() != len(commitID) {
+			return false
+		}
+	} else if objectFormat.FullLength() != len(commitID) {
 		return false
 	}
-
-	return id.IsZero()
+	for _, c := range commitID {
+		if c != '0' {
+			return false
+		}
+	}
+	return true
 }
 
 // ComputeBlobHash compute the hash for a given blob content

modules/git/object_id_test.go

···
 	assert.Equal(t, "d5c6407415d85df49592672aa421aed39b9db5e3", ComputeBlobHash(Sha1ObjectFormat, []byte("same length blob")).String())
 	assert.Equal(t, "df0b5174ed06ae65aea40d43316bcbc21d82c9e3158ce2661df2ad28d7931dd6", ComputeBlobHash(Sha256ObjectFormat, []byte("some random blob")).String())
 }
+
+func TestIsEmptyCommitID(t *testing.T) {
+	assert.True(t, IsEmptyCommitID("", nil))
+	assert.True(t, IsEmptyCommitID("", Sha1ObjectFormat))
+	assert.True(t, IsEmptyCommitID("", Sha256ObjectFormat))
+
+	assert.False(t, IsEmptyCommitID("79ee38a6416c1ede423ec7ee0a8639ceea4aad20", Sha1ObjectFormat))
+	assert.True(t, IsEmptyCommitID("0000000000000000000000000000000000000000", nil))
+	assert.True(t, IsEmptyCommitID("0000000000000000000000000000000000000000", Sha1ObjectFormat))
+	assert.False(t, IsEmptyCommitID("0000000000000000000000000000000000000000", Sha256ObjectFormat))
+
+	assert.False(t, IsEmptyCommitID("00000000000000000000000000000000000000000", nil))
+
+	assert.False(t, IsEmptyCommitID("0f0b5174ed06ae65aea40d43316bcbc21d82c9e3158ce2661df2ad28d7931dd6", nil))
+	assert.True(t, IsEmptyCommitID("0000000000000000000000000000000000000000000000000000000000000000", nil))
+	assert.False(t, IsEmptyCommitID("0000000000000000000000000000000000000000000000000000000000000000", Sha1ObjectFormat))
+	assert.True(t, IsEmptyCommitID("0000000000000000000000000000000000000000000000000000000000000000", Sha256ObjectFormat))
+
+	assert.False(t, IsEmptyCommitID("1", nil))
+	assert.False(t, IsEmptyCommitID("0", nil))
+
+	assert.False(t, IsEmptyCommitID("010", nil))
+	assert.False(t, IsEmptyCommitID("0 0", nil))
+}

modules/repository/push.go

···
 
 // IsNewRef return true if it's a first-time push to a branch, tag or etc.
 func (opts *PushUpdateOptions) IsNewRef() bool {
-	commitID, err := git.NewIDFromString(opts.OldCommitID)
-	return err == nil && commitID.IsZero()
+	return git.IsEmptyCommitID(opts.OldCommitID, nil)
 }
 
 // IsDelRef return true if it's a deletion to a branch or tag
 func (opts *PushUpdateOptions) IsDelRef() bool {
-	commitID, err := git.NewIDFromString(opts.NewCommitID)
-	return err == nil && commitID.IsZero()
+	return git.IsEmptyCommitID(opts.NewCommitID, nil)
 }
 
 // IsUpdateRef return true if it's an update operation

routers/private/hook_post_receive.go

···
 		}
 
 		// If we've pushed a branch (and not deleted it)
-		if !git.IsEmptyCommitID(newCommitID) && refFullName.IsBranch() {
+		if !git.IsEmptyCommitID(newCommitID, nil) && refFullName.IsBranch() {
 			// First ensure we have the repository loaded, we're allowed pulls requests and we can get the base repo
 			if repo == nil {
 				repo = loadRepository(ctx, ownerName, repoName)

services/actions/notifier.go

···
 }
 
 func (n *actionsNotifier) PushCommits(ctx context.Context, pusher *user_model.User, repo *repo_model.Repository, opts *repository.PushUpdateOptions, commits *repository.PushCommits) {
-	commitID, _ := git.NewIDFromString(opts.NewCommitID)
-	if commitID.IsZero() {
+	if git.IsEmptyCommitID(opts.NewCommitID, nil) {
 		log.Trace("new commitID is empty")
 		return
 	}