Use full output of git show-ref --tags to get tags for PushUpdateAddTag (#19235)

Strangely #19038 appears to relate to an issue whereby a tag appears to
be listed in `git show-ref --tags` but then does not appear when `git
show-ref --tags -- short_name` is called.

As a solution though I propose to stop the second call as it is
unnecessary and only likely to cause problems.

I've also noticed that the tags calls are wildly inefficient and aren't using the common cat-files - so these have been added.

I've also noticed that the git commit-graph is not being written on mirroring - so I've also added writing this to the migration which should improve mirror rendering somewhat. 

Fix #19038

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>

1 files changed, 26 insertions, 9 deletions

diff --git a/modules/git/repo_branch_nogogit.go b/modules/git/repo_branch_nogogit.go
index 66990add6f..f595b6d9a8 100644
--- a/modules/git/repo_branch_nogogit.go
+++ b/modules/git/repo_branch_nogogit.go
@@ -68,13 +68,29 @@ func (repo *Repository) GetBranchNames(skip, limit int) ([]string, int, error) {
 }
 
 // WalkReferences walks all the references from the repository
-func WalkReferences(ctx context.Context, repoPath string, walkfn func(string) error) (int, error) {
+func WalkReferences(ctx context.Context, repoPath string, walkfn func(sha1, refname string) error) (int, error) {
 	return walkShowRef(ctx, repoPath, "", 0, 0, walkfn)
 }
 
+// WalkReferences walks all the references from the repository
+// refType should be empty, ObjectTag or ObjectBranch. All other values are equivalent to empty.
+func (repo *Repository) WalkReferences(refType ObjectType, skip, limit int, walkfn func(sha1, refname string) error) (int, error) {
+	var arg string
+	switch refType {
+	case ObjectTag:
+		arg = "--tags"
+	case ObjectBranch:
+		arg = "--heads"
+	default:
+		arg = ""
+	}
+
+	return walkShowRef(repo.Ctx, repo.Path, arg, skip, limit, walkfn)
+}
+
 // callShowRef return refs, if limit = 0 it will not limit
 func callShowRef(ctx context.Context, repoPath, prefix, arg string, skip, limit int) (branchNames []string, countAll int, err error) {
-	countAll, err = walkShowRef(ctx, repoPath, arg, skip, limit, func(branchName string) error {
+	countAll, err = walkShowRef(ctx, repoPath, arg, skip, limit, func(_, branchName string) error {
 		branchName = strings.TrimPrefix(branchName, prefix)
 		branchNames = append(branchNames, branchName)
 
@@ -83,7 +99,7 @@ func callShowRef(ctx context.Context, repoPath, prefix, arg string, skip, limit
 	return
 }
 
-func walkShowRef(ctx context.Context, repoPath, arg string, skip, limit int, walkfn func(string) error) (countAll int, err error) {
+func walkShowRef(ctx context.Context, repoPath, arg string, skip, limit int, walkfn func(sha1, refname string) error) (countAll int, err error) {
 	stdoutReader, stdoutWriter := io.Pipe()
 	defer func() {
 		_ = stdoutReader.Close()
@@ -130,11 +146,7 @@ func walkShowRef(ctx context.Context, repoPath, arg string, skip, limit int, wal
 	for limit == 0 || i < skip+limit {
 		// The output of show-ref is simply a list:
 		// <sha> SP <ref> LF
-		_, err := bufReader.ReadSlice(' ')
-		for err == bufio.ErrBufferFull {
-			// This shouldn't happen but we'll tolerate it for the sake of peace
-			_, err = bufReader.ReadSlice(' ')
-		}
+		sha, err := bufReader.ReadString(' ')
 		if err == io.EOF {
 			return i, nil
 		}
@@ -154,7 +166,12 @@ func walkShowRef(ctx context.Context, repoPath, arg string, skip, limit int, wal
 		if len(branchName) > 0 {
 			branchName = branchName[:len(branchName)-1]
 		}
-		err = walkfn(branchName)
+
+		if len(sha) > 0 {
+			sha = sha[:len(sha)-1]
+		}
+
+		err = walkfn(sha, branchName)
 		if err != nil {
 			return i, err
 		}