Use case-insensitive matching for Git error "Not a valid object name" (#36728)

Fixes #36727

Git is lowercasing the `fatal: Not a valid object name` error message
to follow its CodingGuidelines. This change makes the string matching
case-insensitive so it works with both the current and future Git
versions.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/git/gitcmd/command_test.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"strings"
 	"testing"
 	"time"
 
@@ -49,9 +50,11 @@ func TestRunWithContextStd(t *testing.T) {
 		stdout, stderr, err := cmd.RunStdString(t.Context())
 		if assert.Error(t, err) {
 			assert.Equal(t, stderr, err.Stderr())
-			assert.Equal(t, "fatal: Not a valid object name no-such\n", err.Stderr())
+			stderrLower := strings.ToLower(stderr) // see: IsStdErrorNotValidObjectName
+			assert.Equal(t, "fatal: not a valid object name no-such\n", stderrLower)
 			// FIXME: GIT-CMD-STDERR: it is a bad design, the stderr should not be put in the error message
-			assert.Equal(t, "exit status 128 - fatal: Not a valid object name no-such", err.Error())
+			errLower := strings.ToLower(err.Error())
+			assert.Equal(t, "exit status 128 - fatal: not a valid object name no-such", errLower)
 			assert.Empty(t, stdout)
 		}
 	}
@@ -61,9 +64,11 @@ func TestRunWithContextStd(t *testing.T) {
 		stdout, stderr, err := cmd.RunStdBytes(t.Context())
 		if assert.Error(t, err) {
 			assert.Equal(t, string(stderr), err.Stderr())
-			assert.Equal(t, "fatal: Not a valid object name no-such\n", err.Stderr())
+			stderrLower := strings.ToLower(err.Stderr()) // see: IsStdErrorNotValidObjectName
+			assert.Equal(t, "fatal: not a valid object name no-such\n", stderrLower)
 			// FIXME: GIT-CMD-STDERR: it is a bad design, the stderr should not be put in the error message
-			assert.Equal(t, "exit status 128 - fatal: Not a valid object name no-such", err.Error())
+			errLower := strings.ToLower(err.Error())
+			assert.Equal(t, "exit status 128 - fatal: not a valid object name no-such", errLower)
 			assert.Empty(t, stdout)
 		}
 	}

modules/git/gitcmd/error.go

@@ -77,6 +77,13 @@ func IsErrorCanceledOrKilled(err error) bool {
 	return errors.Is(err, context.Canceled) || IsErrorSignalKilled(err)
 }
 
+func IsStdErrorNotValidObjectName(err error) bool {
+	stderr, ok := ErrorAsStderr(err)
+	// Git is lowercasing the "fatal: Not a valid object name" error message
+	// ref: https://lore.kernel.org/git/pull.2052.git.1771836302101.gitgitgadget@gmail.com
+	return ok && strings.Contains(strings.ToLower(stderr), "fatal: not a valid object name")
+}
+
 type pipelineError struct {
 	error
 }

modules/git/tree_nogogit.go

@@ -65,7 +65,7 @@ func (t *Tree) ListEntries() (Entries, error) {
 
 	stdout, _, runErr := gitcmd.NewCommand("ls-tree", "-l").AddDynamicArguments(t.ID.String()).WithDir(t.repo.Path).RunStdBytes(t.repo.Ctx)
 	if runErr != nil {
-		if strings.Contains(runErr.Error(), "fatal: Not a valid object name") || strings.Contains(runErr.Error(), "fatal: not a tree object") {
+		if gitcmd.IsStdErrorNotValidObjectName(runErr) || strings.Contains(runErr.Error(), "fatal: not a tree object") {
 			return nil, ErrNotExist{
 				ID: t.ID.String(),
 			}

routers/web/repo/pull.go

@@ -282,7 +282,7 @@ func prepareMergedViewPullInfo(ctx *context.Context, issue *issues_model.Issue)
 	compareInfo, err := git_service.GetCompareInfo(ctx, ctx.Repo.Repository, ctx.Repo.Repository, ctx.Repo.GitRepo,
 		git.RefName(baseCommit), git.RefName(pull.GetGitHeadRefName()), false, false)
 	if err != nil {
-		if strings.Contains(err.Error(), "fatal: Not a valid object name") || strings.Contains(err.Error(), "unknown revision or path not in the working tree") {
+		if gitcmd.IsStdErrorNotValidObjectName(err) || strings.Contains(err.Error(), "unknown revision or path not in the working tree") {
 			ctx.Data["IsPullRequestBroken"] = true
 			ctx.Data["BaseTarget"] = pull.BaseBranch
 			ctx.Data["NumCommits"] = 0
@@ -442,7 +442,7 @@ func prepareViewPullInfo(ctx *context.Context, issue *issues_model.Issue) *git_s
 		compareInfo, err := git_service.GetCompareInfo(ctx, pull.BaseRepo, pull.BaseRepo, baseGitRepo,
 			git.RefName(pull.MergeBase), git.RefName(pull.GetGitHeadRefName()), false, false)
 		if err != nil {
-			if strings.Contains(err.Error(), "fatal: Not a valid object name") {
+			if gitcmd.IsStdErrorNotValidObjectName(err) {
 				ctx.Data["IsPullRequestBroken"] = true
 				ctx.Data["BaseTarget"] = pull.BaseBranch
 				ctx.Data["NumCommits"] = 0
@@ -584,7 +584,7 @@ func prepareViewPullInfo(ctx *context.Context, issue *issues_model.Issue) *git_s
 	compareInfo, err := git_service.GetCompareInfo(ctx, pull.BaseRepo, pull.BaseRepo, baseGitRepo,
 		git.RefNameFromBranch(pull.BaseBranch), git.RefName(pull.GetGitHeadRefName()), false, false)
 	if err != nil {
-		if strings.Contains(err.Error(), "fatal: Not a valid object name") {
+		if gitcmd.IsStdErrorNotValidObjectName(err) {
 			ctx.Data["IsPullRequestBroken"] = true
 			ctx.Data["BaseTarget"] = pull.BaseBranch
 			ctx.Data["NumCommits"] = 0

services/wiki/wiki.go

@@ -8,7 +8,6 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"strings"
 
 	"code.gitea.io/gitea/models/db"
 	repo_model "code.gitea.io/gitea/models/repo"
@@ -16,6 +15,7 @@ import (
 	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/git/gitcmd"
 	"code.gitea.io/gitea/modules/gitrepo"
 	"code.gitea.io/gitea/modules/globallock"
 	"code.gitea.io/gitea/modules/graceful"
@@ -59,7 +59,7 @@ func prepareGitPath(gitRepo *git.Repository, defaultWikiBranch string, wikiPath
 	// Look for both files
 	filesInIndex, err := gitRepo.LsTree(defaultWikiBranch, unescaped, gitPath)
 	if err != nil {
-		if strings.Contains(err.Error(), "Not a valid object name") {
+		if gitcmd.IsStdErrorNotValidObjectName(err) {
 			return false, gitPath, nil // branch doesn't exist
 		}
 		log.Error("Wiki LsTree failed, err: %v", err)