Refactor git_repository_open with new options

Add a new command `git_repository_open_ext` with extended options
that control how searching for a repository will be done.  The
existing `git_repository_open` and `git_repository_discover` are
reimplemented on top of it.  We may want to change the default
behavior of `git_repository_open` but this commit does not do that.

Improve support for "gitdir" files where the work dir is separate
from the repo and support for the "separate-git-dir" config.  Also,
add support for opening repos created with `git-new-workdir` script
(although I have only confirmed that they can be opened, not that
all functions work correctly).

There are also a few minor changes that came up:

- Fix `git_path_prettify` to allow in-place prettifying.

- Fix `git_path_root` to support backslashes on Win32.  This fix
  should help many repo open/discover scenarios - it is the one
  function called when opening before prettifying the path.

- Tweak `git_config_get_string` to set the "out" pointer to NULL
  if the config value is not found.  Allows some other cleanup.

- Fix a couple places that should have been calling
  `git_repository_config__weakptr` and were not.

- Fix `cl_git_sandbox_init` clar helper to support bare repos.

1 files changed, 239 insertions, 11 deletions

diff --git a/tests-clar/repo/open.c b/tests-clar/repo/open.c
index c3a7dadbd..28bae40fa 100644
--- a/tests-clar/repo/open.c
+++ b/tests-clar/repo/open.c
@@ -1,25 +1,27 @@
 #include "clar_libgit2.h"
-#include "posix.h"
-
-static git_repository *repo;
+#include "fileops.h"
 
 void test_repo_open__cleanup(void)
 {
-	git_repository_free(repo);
+	cl_git_sandbox_cleanup();
+
+	if (git_path_isdir("alternate"))
+		git_futils_rmdir_r("alternate", 1);
 }
 
 void test_repo_open__bare_empty_repo(void)
 {
-	cl_git_pass(git_repository_open(&repo, cl_fixture("empty_bare.git")));
+	git_repository *repo = cl_git_sandbox_init("empty_bare.git");
 
 	cl_assert(git_repository_path(repo) != NULL);
 	cl_assert(git__suffixcmp(git_repository_path(repo), "/") == 0);
-
 	cl_assert(git_repository_workdir(repo) == NULL);
 }
 
 void test_repo_open__standard_empty_repo_through_gitdir(void)
 {
+	git_repository *repo;
+
 	cl_git_pass(git_repository_open(&repo, cl_fixture("empty_standard_repo/.gitted")));
 
 	cl_assert(git_repository_path(repo) != NULL);
@@ -27,20 +29,246 @@ void test_repo_open__standard_empty_repo_through_gitdir(void)
 
 	cl_assert(git_repository_workdir(repo) != NULL);
 	cl_assert(git__suffixcmp(git_repository_workdir(repo), "/") == 0);
+
+	git_repository_free(repo);
 }
 
 void test_repo_open__standard_empty_repo_through_workdir(void)
 {
-	cl_fixture_sandbox("empty_standard_repo");
-	cl_git_pass(p_rename("empty_standard_repo/.gitted", "empty_standard_repo/.git"));
-
-	cl_git_pass(git_repository_open(&repo, "empty_standard_repo"));
+	git_repository *repo = cl_git_sandbox_init("empty_standard_repo");
 
 	cl_assert(git_repository_path(repo) != NULL);
 	cl_assert(git__suffixcmp(git_repository_path(repo), "/") == 0);
 
 	cl_assert(git_repository_workdir(repo) != NULL);
 	cl_assert(git__suffixcmp(git_repository_workdir(repo), "/") == 0);
+}
+
+
+void test_repo_open__open_with_discover(void)
+{
+	static const char *variants[] = {
+		"attr", "attr/", "attr/.git", "attr/.git/",
+		"attr/sub", "attr/sub/", "attr/sub/sub", "attr/sub/sub/",
+		NULL
+	};
+	git_repository *repo;
+	const char **scan;
+
+	cl_fixture_sandbox("attr");
+	cl_git_pass(p_rename("attr/.gitted", "attr/.git"));
+
+	for (scan = variants; *scan != NULL; scan++) {
+		cl_git_pass(git_repository_open_ext(&repo, *scan, 0, NULL));
+		cl_assert(git__suffixcmp(git_repository_path(repo), "attr/.git/") == 0);
+		cl_assert(git__suffixcmp(git_repository_workdir(repo), "attr/") == 0);
+		git_repository_free(repo);
+	}
+
+	cl_fixture_cleanup("attr");
+}
+
+void test_repo_open__gitlinked(void)
+{
+	/* need to have both repo dir and workdir set up correctly */
+	git_repository *repo = cl_git_sandbox_init("empty_standard_repo");
+	git_repository *repo2;
+
+	cl_must_pass(p_mkdir("alternate", 0777));
+	cl_git_mkfile("alternate/.git", "gitdir: ../empty_standard_repo/.git");
+
+	cl_git_pass(git_repository_open(&repo2, "alternate"));
+
+	cl_assert(git_repository_path(repo2) != NULL);
+	cl_assert_(git__suffixcmp(git_repository_path(repo2), "empty_standard_repo/.git/") == 0, git_repository_path(repo2));
+	cl_assert_equal_s(git_repository_path(repo), git_repository_path(repo2));
+
+	cl_assert(git_repository_workdir(repo2) != NULL);
+	cl_assert_(git__suffixcmp(git_repository_workdir(repo2), "alternate/") == 0, git_repository_workdir(repo2));
+
+	git_repository_free(repo2);
+}
+
+void test_repo_open__from_git_new_workdir(void)
+{
+	/* The git-new-workdir script that ships with git sets up a bunch of
+	 * symlinks to create a second workdir that shares the object db with
+	 * another checkout.  Libgit2 can open a repo that has been configured
+	 * this way.
+	 */
+	cl_git_sandbox_init("empty_standard_repo");
+
+#ifndef GIT_WIN32
+	git_repository *repo2;
+	git_buf link_tgt = GIT_BUF_INIT, link = GIT_BUF_INIT, body = GIT_BUF_INIT;
+	const char **scan;
+	int link_fd;
+	static const char *links[] = {
+		"config", "refs", "logs/refs", "objects", "info", "hooks",
+		"packed-refs", "remotes", "rr-cache", "svn", NULL
+	};
+	static const char *copies[] = {
+		"HEAD", NULL
+	};
+
+	cl_git_pass(p_mkdir("alternate", 0777));
+	cl_git_pass(p_mkdir("alternate/.git", 0777));
+
+	for (scan = links; *scan != NULL; scan++) {
+		git_buf_joinpath(&link_tgt, "empty_standard_repo/.git", *scan);
+		if (git_path_exists(link_tgt.ptr)) {
+			git_buf_joinpath(&link_tgt, "../../empty_standard_repo/.git", *scan);
+			git_buf_joinpath(&link, "alternate/.git", *scan);
+			if (strchr(*scan, '/'))
+				git_futils_mkpath2file(link.ptr, 0777);
+			cl_assert_(symlink(link_tgt.ptr, link.ptr) == 0, strerror(errno));
+		}
+	}
+	for (scan = copies; *scan != NULL; scan++) {
+		git_buf_joinpath(&link_tgt, "empty_standard_repo/.git", *scan);
+		if (git_path_exists(link_tgt.ptr)) {
+			git_buf_joinpath(&link, "alternate/.git", *scan);
+			cl_git_pass(git_futils_readbuffer(&body, link_tgt.ptr));
+
+			cl_assert((link_fd = git_futils_creat_withpath(link.ptr, 0777, 0666)) >= 0);
+			cl_must_pass(p_write(link_fd, body.ptr, body.size));
+			p_close(link_fd);
+		}
+	}
+
+	git_buf_free(&link_tgt);
+	git_buf_free(&link);
+	git_buf_free(&body);
+
+
+	cl_git_pass(git_repository_open(&repo2, "alternate"));
+
+	cl_assert(git_repository_path(repo2) != NULL);
+	cl_assert_(git__suffixcmp(git_repository_path(repo2), "alternate/.git/") == 0, git_repository_path(repo2));
+
+	cl_assert(git_repository_workdir(repo2) != NULL);
+	cl_assert_(git__suffixcmp(git_repository_workdir(repo2), "alternate/") == 0, git_repository_workdir(repo2));
+
+	git_repository_free(repo2);
+#endif
+}
+
+void test_repo_open__failures(void)
+{
+	git_repository *base, *repo;
+	git_buf ceiling = GIT_BUF_INIT;
+
+	base = cl_git_sandbox_init("attr");
+	cl_git_pass(git_buf_sets(&ceiling, git_repository_workdir(base)));
+
+	/* fail with no searching */
+	cl_git_fail(git_repository_open(&repo, "attr/sub"));
+	cl_git_fail(git_repository_open_ext(
+		&repo, "attr/sub", GIT_REPOSITORY_OPEN_NO_SEARCH, NULL));
+
+	/* fail with ceiling too low */
+	cl_git_pass(git_buf_joinpath(&ceiling, ceiling.ptr, "sub"));
+	cl_git_fail(git_repository_open_ext(&repo, "attr/sub", 0, ceiling.ptr));
+
+	/* fail with no repo */
+	cl_git_pass(p_mkdir("alternate", 0777));
+	cl_git_pass(p_mkdir("alternate/.git", 0777));
+	cl_git_fail(git_repository_open_ext(&repo, "alternate", 0, NULL));
+	cl_git_fail(git_repository_open_ext(&repo, "alternate/.git", 0, NULL));
+
+	git_buf_free(&ceiling);
+}
+
+void test_repo_open__bad_gitlinks(void)
+{
+	git_repository *repo;
+	static const char *bad_links[] = {
+		"garbage\n", "gitdir", "gitdir:\n", "gitdir: foobar",
+		"gitdir: ../invalid", "gitdir: ../invalid2",
+		"gitdir: ../attr/.git with extra stuff",
+		NULL
+	};
+	const char **scan;
+
+	cl_git_sandbox_init("attr");
+
+	cl_git_pass(p_mkdir("alternate", 0777));
+	cl_git_pass(p_mkdir("invalid", 0777));
+	cl_git_pass(git_futils_mkdir_r("invalid2/.git", NULL, 0777));
+
+	for (scan = bad_links; *scan != NULL; scan++) {
+		cl_git_rewritefile("alternate/.git", *scan);
+		cl_git_fail(git_repository_open_ext(&repo, "alternate", 0, NULL));
+	}
+
+	git_futils_rmdir_r("invalid", 1);
+	git_futils_rmdir_r("invalid2", 1);
+}
+
+static void unposix_path(git_buf *path)
+{
+	char *src, *tgt;
+
+	src = tgt = path->ptr;
+
+	/* convert "/d/..." to "d:\..." */
+	if (src[0] == '/' && isalpha(src[1]) && src[2] == '/') {
+		*tgt++ = src[1];
+		*tgt++ = ':';
+		*tgt++ = '\\';
+		src += 3;
+	}
+
+	while (*src) {
+		*tgt++ = (*src == '/') ? '\\' : *src;
+		src++;
+	}
+
+	*tgt = '\0';
+}
+
+void test_repo_open__win32_path(void)
+{
+#ifdef GIT_WIN32
+	git_repository *repo = cl_git_sandbox_init("empty_standard_repo"), *repo2;
+	git_buf winpath = GIT_BUF_INIT;
+	char *src, *tgt;
+	static const char *repo_path = "empty_standard_repo/.git/";
+	static const char *repo_wd   = "empty_standard_repo/";
+
+	cl_assert(git__suffixcmp(git_repository_path(repo), repo_path) == 0);
+	cl_assert(git__suffixcmp(git_repository_workdir(repo), repo_wd) == 0);
+
+	cl_git_pass(git_buf_sets(&winpath, git_repository_path(repo)));
+	unposix_path(&winpath);
+	cl_git_pass(git_repository_open(&repo2, winpath.ptr));
+	cl_assert(git__suffixcmp(git_repository_path(repo2), repo_path) == 0);
+	cl_assert(git__suffixcmp(git_repository_workdir(repo2), repo_wd) == 0);
+	git_repository_free(repo2);
+
+	cl_git_pass(git_buf_sets(&winpath, git_repository_path(repo)));
+	git_buf_truncate(&winpath, winpath.size - 1); /* remove trailing '/' */
+	unposix_path(&winpath);
+	cl_git_pass(git_repository_open(&repo2, winpath.ptr));
+	cl_assert(git__suffixcmp(git_repository_path(repo2), repo_path) == 0);
+	cl_assert(git__suffixcmp(git_repository_workdir(repo2), repo_wd) == 0);
+	git_repository_free(repo2);
+
+	cl_git_pass(git_buf_sets(&winpath, git_repository_workdir(repo)));
+	unposix_path(&winpath);
+	cl_git_pass(git_repository_open(&repo2, winpath.ptr));
+	cl_assert(git__suffixcmp(git_repository_path(repo2), repo_path) == 0);
+	cl_assert(git__suffixcmp(git_repository_workdir(repo2), repo_wd) == 0);
+	git_repository_free(repo2);
+
+	cl_git_pass(git_buf_sets(&winpath, git_repository_workdir(repo)));
+	git_buf_truncate(&winpath, winpath.size - 1); /* remove trailing '/' */
+	unposix_path(&winpath);
+	cl_git_pass(git_repository_open(&repo2, winpath.ptr));
+	cl_assert(git__suffixcmp(git_repository_path(repo2), repo_path) == 0);
+	cl_assert(git__suffixcmp(git_repository_workdir(repo2), repo_wd) == 0);
+	git_repository_free(repo2);
 
-	cl_fixture_cleanup("empty_standard_repo");
+	git_buf_free(&winpath);
+#endif
 }