git2go: Move errors used by UserUpdateSubmodule RPC

The "internal/git2go" package still hosts a bunch of errors which are
used by the UserUpdateSubmodulie RPC and nothing else. Furthermore, two
of the three errors are actually never raised anymore, so there is no
point in handling them.

Move the single error that is still being used over to where its used.

2 files changed, 15 insertions, 26 deletions

diff --git a/internal/git2go/submodule.go b/internal/git2go/submodule.go
deleted file mode 100644
index 757fef6a1..000000000
--- a/internal/git2go/submodule.go
+++ /dev/null
@@ -1,8 +0,0 @@
-package git2go
-
-// Error strings present in the legacy Ruby implementation
-const (
-	LegacyErrPrefixInvalidBranch        = "Invalid branch"
-	LegacyErrPrefixInvalidSubmodulePath = "Invalid submodule path"
-	LegacyErrPrefixFailedCommit         = "Failed to create commit"
-)
diff --git a/internal/gitaly/service/operations/submodules.go b/internal/gitaly/service/operations/submodules.go
index 1323379be..6ba4911bf 100644
--- a/internal/gitaly/service/operations/submodules.go
+++ b/internal/gitaly/service/operations/submodules.go
@@ -9,13 +9,17 @@ import (
 	"github.com/grpc-ecosystem/go-grpc-middleware/logging/logrus/ctxlogrus"
 	"gitlab.com/gitlab-org/gitaly/v16/internal/git"
 	"gitlab.com/gitlab-org/gitaly/v16/internal/git/localrepo"
-	"gitlab.com/gitlab-org/gitaly/v16/internal/git2go"
 	"gitlab.com/gitlab-org/gitaly/v16/internal/gitaly/hook/updateref"
 	"gitlab.com/gitlab-org/gitaly/v16/internal/gitaly/storage"
 	"gitlab.com/gitlab-org/gitaly/v16/internal/structerr"
 	"gitlab.com/gitlab-org/gitaly/v16/proto/go/gitalypb"
 )
 
+// Error strings present in the legacy Ruby implementation.
+const (
+	legacyErrPrefixInvalidSubmodulePath = "Invalid submodule path"
+)
+
 //nolint:revive // This is unintentionally missing documentation.
 func (s *Server) UserUpdateSubmodule(ctx context.Context, req *gitalypb.UserUpdateSubmoduleRequest) (*gitalypb.UserUpdateSubmoduleResponse, error) {
 	if err := s.locator.ValidateRepository(req.GetRepository()); err != nil {
@@ -80,21 +84,14 @@ func (s *Server) UserUpdateSubmodule(ctx context.Context, req *gitalypb.UserUpda
 		errStr := strings.TrimSpace(err.Error())
 
 		var resp *gitalypb.UserUpdateSubmoduleResponse
-		for _, legacyErr := range []string{
-			git2go.LegacyErrPrefixInvalidBranch,
-			git2go.LegacyErrPrefixInvalidSubmodulePath,
-			git2go.LegacyErrPrefixFailedCommit,
-		} {
-			if strings.Contains(errStr, legacyErr) {
-				resp = &gitalypb.UserUpdateSubmoduleResponse{
-					CommitError: legacyErr,
-				}
-				ctxlogrus.
-					Extract(ctx).
-					WithError(err).
-					Error("UserUpdateSubmodule: git2go subcommand failure")
-				break
+		if strings.Contains(errStr, legacyErrPrefixInvalidSubmodulePath) {
+			resp = &gitalypb.UserUpdateSubmoduleResponse{
+				CommitError: legacyErrPrefixInvalidSubmodulePath,
 			}
+			ctxlogrus.
+				Extract(ctx).
+				WithError(err).
+				Error("UserUpdateSubmodule: git2go subcommand failure")
 		}
 		if strings.Contains(errStr, "is already at") {
 			resp = &gitalypb.UserUpdateSubmoduleResponse{
@@ -200,7 +197,7 @@ func (s *Server) updateSubmodule(ctx context.Context, quarantineRepo *localrepo.
 	)
 	if err != nil {
 		if errors.Is(err, git.ErrReferenceNotFound) {
-			return "", fmt.Errorf("submodule: %s", git2go.LegacyErrPrefixInvalidSubmodulePath)
+			return "", fmt.Errorf("submodule: %s", legacyErrPrefixInvalidSubmodulePath)
 		}
 
 		return "", fmt.Errorf("error reading tree: %w", err)
@@ -212,7 +209,7 @@ func (s *Server) updateSubmodule(ctx context.Context, quarantineRepo *localrepo.
 			replaceWith := git.ObjectID(req.GetCommitSha())
 
 			if t.Type != localrepo.Submodule {
-				return fmt.Errorf("submodule: %s", git2go.LegacyErrPrefixInvalidSubmodulePath)
+				return fmt.Errorf("submodule: %s", legacyErrPrefixInvalidSubmodulePath)
 			}
 
 			if replaceWith == t.OID {
@@ -228,7 +225,7 @@ func (s *Server) updateSubmodule(ctx context.Context, quarantineRepo *localrepo.
 		},
 	); err != nil {
 		if err == localrepo.ErrEntryNotFound {
-			return "", fmt.Errorf("submodule: %s", git2go.LegacyErrPrefixInvalidSubmodulePath)
+			return "", fmt.Errorf("submodule: %s", legacyErrPrefixInvalidSubmodulePath)
 		}
 
 		var git2GoErr *legacyGit2GoSubmoduleAlreadyAtShaError