Merge branch 'jk/git-dir-lookup' into maint

* jk/git-dir-lookup:
  standardize and improve lookup rules for external local repos

builtin/clone.c

@@ -105,7 +105,7 @@ static const char *argv_submodule[] = {
 
 static char *get_repo_path(const char *repo, int *is_bundle)
 {
-	static char *suffix[] = { "/.git", ".git", "" };
+	static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
 	static char *bundle_suffix[] = { ".bundle", "" };
 	struct stat st;
 	int i;
@@ -115,7 +115,7 @@ static char *get_repo_path(const char *repo, int *is_bundle)
 		path = mkpath("%s%s", repo, suffix[i]);
 		if (stat(path, &st))
 			continue;
-		if (S_ISDIR(st.st_mode)) {
+		if (S_ISDIR(st.st_mode) && is_git_directory(path)) {
 			*is_bundle = 0;
 			return xstrdup(absolute_path(path));
 		} else if (S_ISREG(st.st_mode) && st.st_size > 8) {

cache.h

@@ -432,6 +432,7 @@ extern char *git_work_tree_cfg;
 extern int is_inside_work_tree(void);
 extern int have_git_dir(void);
 extern const char *get_git_dir(void);
+extern int is_git_directory(const char *path);
 extern char *get_object_directory(void);
 extern char *get_index_file(void);
 extern char *get_graft_file(void);

path.c

@@ -293,7 +293,7 @@ const char *enter_repo(const char *path, int strict)
 
 	if (!strict) {
 		static const char *suffix[] = {
-			".git/.git", "/.git", ".git", "", NULL,
+			"/.git", "", ".git/.git", ".git", NULL,
 		};
 		const char *gitfile;
 		int len = strlen(path);
@@ -324,8 +324,11 @@ const char *enter_repo(const char *path, int strict)
 			return NULL;
 		len = strlen(used_path);
 		for (i = 0; suffix[i]; i++) {
+			struct stat st;
 			strcpy(used_path + len, suffix[i]);
-			if (!access(used_path, F_OK)) {
+			if (!stat(used_path, &st) &&
+			    (S_ISREG(st.st_mode) ||
+			    (S_ISDIR(st.st_mode) && is_git_directory(used_path)))) {
 				strcat(validated_path, suffix[i]);
 				break;
 			}

setup.c

@@ -247,7 +247,7 @@ const char **get_pathspec(const char *prefix, const char **pathspec)
  *    a proper "ref:", or a regular file HEAD that has a properly
  *    formatted sha1 object name.
  */
-static int is_git_directory(const char *suspect)
+int is_git_directory(const char *suspect)
 {
 	char path[PATH_MAX];
 	size_t len = strlen(suspect);

t/t5900-repo-selection.sh

@@ -0,0 +1,100 @@
+#!/bin/sh
+
+test_description='selecting remote repo in ambiguous cases'
+. ./test-lib.sh
+
+reset() {
+	rm -rf foo foo.git fetch clone
+}
+
+make_tree() {
+	git init "$1" &&
+	(cd "$1" && test_commit "$1")
+}
+
+make_bare() {
+	git init --bare "$1" &&
+	(cd "$1" &&
+	 tree=`git hash-object -w -t tree /dev/null` &&
+	 commit=$(echo "$1" | git commit-tree $tree) &&
+	 git update-ref HEAD $commit
+	)
+}
+
+get() {
+	git init --bare fetch &&
+	(cd fetch && git fetch "../$1") &&
+	git clone "$1" clone
+}
+
+check() {
+	echo "$1" >expect &&
+	(cd fetch && git log -1 --format=%s FETCH_HEAD) >actual.fetch &&
+	(cd clone && git log -1 --format=%s HEAD) >actual.clone &&
+	test_cmp expect actual.fetch &&
+	test_cmp expect actual.clone
+}
+
+test_expect_success 'find .git dir in worktree' '
+	reset &&
+	make_tree foo &&
+	get foo &&
+	check foo
+'
+
+test_expect_success 'automagically add .git suffix' '
+	reset &&
+	make_bare foo.git &&
+	get foo &&
+	check foo.git
+'
+
+test_expect_success 'automagically add .git suffix to worktree' '
+	reset &&
+	make_tree foo.git &&
+	get foo &&
+	check foo.git
+'
+
+test_expect_success 'prefer worktree foo over bare foo.git' '
+	reset &&
+	make_tree foo &&
+	make_bare foo.git &&
+	get foo &&
+	check foo
+'
+
+test_expect_success 'prefer bare foo over bare foo.git' '
+	reset &&
+	make_bare foo &&
+	make_bare foo.git &&
+	get foo &&
+	check foo
+'
+
+test_expect_success 'disambiguate with full foo.git' '
+	reset &&
+	make_bare foo &&
+	make_bare foo.git &&
+	get foo.git &&
+	check foo.git
+'
+
+test_expect_success 'we are not fooled by non-git foo directory' '
+	reset &&
+	make_bare foo.git &&
+	mkdir foo &&
+	get foo &&
+	check foo.git
+'
+
+test_expect_success 'prefer inner .git over outer bare' '
+	reset &&
+	make_tree foo &&
+	make_bare foo.git &&
+	mv foo/.git foo.git &&
+	get foo.git &&
+	check foo
+'
+
+test_done