Merge pull request #227 from Romain-Geissler/discovery-path-v2

Discovery path v2

5 files changed, 350 insertions, 49 deletions

diff --git a/src/filebuf.c b/src/filebuf.c
index 63f2897cb..97dec83f3 100644
--- a/src/filebuf.c
+++ b/src/filebuf.c
@@ -41,16 +41,14 @@ static int lock_file(git_filebuf *file, int flags)
 
 	/* create path to the file buffer is required */
 	if (flags & GIT_FILEBUF_FORCE) {
-		file->fd = gitfo_creat_force(file->path_lock, 0644);
+		file->fd = gitfo_creat_locked_force(file->path_lock, 0644);
 	} else {
-		file->fd = gitfo_creat(file->path_lock, 0644);
+		file->fd = gitfo_creat_locked(file->path_lock, 0644);
 	}
 
 	if (file->fd < 0)
 		return git__throw(GIT_EOSERR, "Failed to create lock");
 
-	/* TODO: do a flock() in the descriptor file_lock */
-
 	if ((flags & GIT_FILEBUF_APPEND) && gitfo_exists(file->path_original) == 0) {
 		git_file source;
 		char buffer[2048];
diff --git a/src/fileops.c b/src/fileops.c
index 73939349d..56bf2927f 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -66,6 +66,20 @@ int gitfo_creat_force(const char *path, int mode)
 	return gitfo_creat(path, mode);
 }
 
+int gitfo_creat_locked(const char *path, int mode)
+{
+	int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_EXCL, mode);
+	return fd >= 0 ? fd : git__throw(GIT_EOSERR, "Failed to create locked file. Could not open %s", path);
+}
+
+int gitfo_creat_locked_force(const char *path, int mode)
+{
+	if (gitfo_mkdir_2file(path) < GIT_SUCCESS)
+		return git__throw(GIT_EOSERR, "Failed to create locked file %s", path);
+
+	return gitfo_creat_locked(path, mode);
+}
+
 int gitfo_read(git_file fd, void *buf, size_t cnt)
 {
 	char *b = buf;
@@ -131,7 +145,26 @@ int gitfo_isdir(const char *path)
 		return git__throw(GIT_ENOTFOUND, "%s does not exist", path);
 
 	if (!S_ISDIR(st.st_mode))
-		return git__throw(GIT_ENOTFOUND, "%s is a file", path);
+		return git__throw(GIT_ENOTFOUND, "%s is not a directory", path);
+
+	return GIT_SUCCESS;
+}
+
+int gitfo_isfile(const char *path)
+{
+	struct stat st;
+	int stat_error;
+
+	if (!path)
+		return git__throw(GIT_ENOTFOUND, "No path given to gitfo_isfile");
+
+	stat_error = gitfo_stat(path, &st);
+
+	if (stat_error < GIT_SUCCESS)
+		return git__throw(GIT_ENOTFOUND, "%s does not exist", path);
+
+	if (!S_ISREG(st.st_mode))
+		return git__throw(GIT_ENOTFOUND, "%s is not a file", path);
 
 	return GIT_SUCCESS;
 }
@@ -301,8 +334,19 @@ int gitfo_dirent(
 	return GIT_SUCCESS;
 }
 
+void gitfo_posixify_path(char *path)
+{
+	#if GIT_PLATFORM_PATH_SEP != '/'
+		while (*path) {
+			if (*path == GIT_PLATFORM_PATH_SEP)
+				*path = '/';
 
-int retrieve_path_root_offset(const char *path)
+			path++;
+		}
+	#endif
+}
+
+int gitfo_retrieve_path_root_offset(const char *path)
 {
 	int offset = 0;
 
@@ -320,7 +364,6 @@ int retrieve_path_root_offset(const char *path)
 	return -1;	/* Not a real error. Rather a signal than the path is not rooted */
 }
 
-
 int gitfo_mkdir_recurs(const char *path, int mode)
 {
 	int error, root_path_offset;
@@ -333,7 +376,7 @@ int gitfo_mkdir_recurs(const char *path, int mode)
 	error = GIT_SUCCESS;
 	pp = path_copy;
 
-	root_path_offset = retrieve_path_root_offset(pp);
+	root_path_offset = gitfo_retrieve_path_root_offset(pp);
 	if (root_path_offset > 0)
 		pp += root_path_offset; /* On Windows, will skip the drive name (eg. C: or D:) */
 
@@ -367,7 +410,7 @@ static int retrieve_previous_path_component_start(const char *path)
 {
 	int offset, len, root_offset, start = 0;
 
-	root_offset = retrieve_path_root_offset(path);
+	root_offset = gitfo_retrieve_path_root_offset(path);
 	if (root_offset > -1)
 		start += root_offset;
 
@@ -392,7 +435,7 @@ static int retrieve_previous_path_component_start(const char *path)
 	return offset;
 }
 
-int gitfo_prettify_dir_path(char *buffer_out, size_t size, const char *path)
+int gitfo_prettify_dir_path(char *buffer_out, size_t size, const char *path, const char *base_path)
 {
 	int len = 0, segment_len, only_dots, root_path_offset, error = GIT_SUCCESS;
 	char *current;
@@ -402,11 +445,20 @@ int gitfo_prettify_dir_path(char *buffer_out, size_t size, const char *path)
 	buffer_end = path + strlen(path);
 	buffer_out_start = buffer_out;
 
-	root_path_offset = retrieve_path_root_offset(path);
+	root_path_offset = gitfo_retrieve_path_root_offset(path);
 	if (root_path_offset < 0) {
-		error = gitfo_getcwd(buffer_out, size);
-		if (error < GIT_SUCCESS)
-			return error;	/* The callee already takes care of setting the correct error message. */
+		if (base_path == NULL) {
+			error = gitfo_getcwd(buffer_out, size);
+			if (error < GIT_SUCCESS)
+				return error;	/* The callee already takes care of setting the correct error message. */
+		} else {
+			if (size < (strlen(base_path) + 1) * sizeof(char))
+				return git__throw(GIT_EOVERFLOW, "Failed to prettify dir path: the base path is too long for the buffer.");
+
+			strcpy(buffer_out, base_path);
+			gitfo_posixify_path(buffer_out);
+			git__joinpath(buffer_out, buffer_out, "");
+		}
 
 		len = strlen(buffer_out);
 		buffer_out += len;
@@ -470,9 +522,9 @@ int gitfo_prettify_dir_path(char *buffer_out, size_t size, const char *path)
 	return GIT_SUCCESS;
 }
 
-int gitfo_prettify_file_path(char *buffer_out, size_t size, const char *path)
+int gitfo_prettify_file_path(char *buffer_out, size_t size, const char *path, const char *base_path)
 {
-	int error, path_len, i;
+	int error, path_len, i, root_offset;
 	const char* pattern = "/..";
 
 	path_len = strlen(path);
@@ -487,12 +539,13 @@ int gitfo_prettify_file_path(char *buffer_out, size_t size, const char *path)
 			return git__throw(GIT_EINVALIDPATH, "Failed to normalize file path `%s`. The path points to a folder", path);
 	}
 
-	error =  gitfo_prettify_dir_path(buffer_out, size, path);
+	error =  gitfo_prettify_dir_path(buffer_out, size, path, base_path);
 	if (error < GIT_SUCCESS)
 		return error;	/* The callee already takes care of setting the correct error message. */
 
 	path_len = strlen(buffer_out);
-	if (path_len < 2)	/* TODO: Fixme. We should also take of detecting Windows rooted path (probably through usage of retrieve_path_root_offset) */
+	root_offset = gitfo_retrieve_path_root_offset(buffer_out) + 1;
+	if (path_len == root_offset)
 		return git__throw(GIT_EINVALIDPATH, "Failed to normalize file path `%s`. The path points to a folder", path);
 
 	/* Remove the trailing slash */
@@ -519,16 +572,6 @@ int gitfo_cmp_path(const char *name1, int len1, int isdir1,
 	return 0;
 }
 
-static void posixify_path(char *path)
-{
-	while (*path) {
-		if (*path == '\\')
-			*path = '/';
-
-		path++;
-	}
-}
-
 int gitfo_getcwd(char *buffer_out, size_t size)
 {
 	char *cwd_buffer;
@@ -544,7 +587,7 @@ int gitfo_getcwd(char *buffer_out, size_t size)
 	if (cwd_buffer == NULL)
 		return git__throw(GIT_EOSERR, "Failed to retrieve current working directory");
 
-	posixify_path(buffer_out);
+	gitfo_posixify_path(buffer_out);
 
 	git__joinpath(buffer_out, buffer_out, "");	//Ensure the path ends with a trailing slash
 
diff --git a/src/fileops.h b/src/fileops.h
index d0381b675..4a86e1c63 100644
--- a/src/fileops.h
+++ b/src/fileops.h
@@ -12,6 +12,14 @@
 #include <fcntl.h>
 #include <time.h>
 
+#define GIT_PATH_LIST_SEPARATOR ':'
+
+#ifdef GIT_WIN32
+#define GIT_PLATFORM_PATH_SEP '\\'
+#else
+#define GIT_PLATFORM_PATH_SEP '/'
+#endif
+
 #ifdef GIT_WIN32
 GIT_INLINE(int) link(const char *GIT_UNUSED(old), const char *GIT_UNUSED(new))
 {
@@ -57,8 +65,11 @@ extern int gitfo_exists(const char *path);
 extern int gitfo_open(const char *path, int flags);
 extern int gitfo_creat(const char *path, int mode);
 extern int gitfo_creat_force(const char *path, int mode);
+extern int gitfo_creat_locked(const char *path, int mode);
+extern int gitfo_creat_locked_force(const char *path, int mode);
 extern int gitfo_mktemp(char *path_out, const char *filename);
 extern int gitfo_isdir(const char *path);
+extern int gitfo_isfile(const char *path);
 extern int gitfo_mkdir_recurs(const char *path, int mode);
 extern int gitfo_mkdir_2file(const char *path);
 #define gitfo_close(fd) close(fd)
@@ -162,7 +173,7 @@ extern int gitfo_getcwd(char *buffer_out, size_t size);
  * - GIT_SUCCESS on success;
  * - GIT_ERROR when the input path is invalid or escapes the current directory.
  */
-int gitfo_prettify_dir_path(char *buffer_out, size_t size, const char *path);
+int gitfo_prettify_dir_path(char *buffer_out, size_t size, const char *path, const char *base_path);
 
 /**
  * Clean up a provided absolute or relative file path.
@@ -185,7 +196,10 @@ int gitfo_prettify_dir_path(char *buffer_out, size_t size, const char *path);
  * - GIT_SUCCESS on success;
  * - GIT_ERROR when the input path is invalid or escapes the current directory.
  */
-int gitfo_prettify_file_path(char *buffer_out, size_t size, const char *path);
+int gitfo_prettify_file_path(char *buffer_out, size_t size, const char *path, const char *base_path);
+
+void gitfo_posixify_path(char *path);
+
+int gitfo_retrieve_path_root_offset(const char *path);
 
-int retrieve_path_root_offset(const char *path);
 #endif /* INCLUDE_fileops_h__ */
diff --git a/src/repository.c b/src/repository.c
index 32ca8dd79..0b67d144c 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -38,6 +38,9 @@
 #define GIT_OBJECTS_INFO_DIR GIT_OBJECTS_DIR "info/"
 #define GIT_OBJECTS_PACK_DIR GIT_OBJECTS_DIR "pack/"
 
+#define GIT_FILE_CONTENT_PREFIX "gitdir: "
+#define GIT_FILE_CONTENT_PREFIX_LENGTH 8
+
 #define GIT_BRANCH_MASTER "master"
 
 typedef struct {
@@ -65,7 +68,7 @@ static int assign_repository_dirs(
 	if (git_dir == NULL)
 		return git__throw(GIT_ENOTFOUND, "Failed to open repository. Git dir not found");
 
-	error = gitfo_prettify_dir_path(path_aux, sizeof(path_aux), git_dir);
+	error = gitfo_prettify_dir_path(path_aux, sizeof(path_aux), git_dir, NULL);
 	if (error < GIT_SUCCESS)
 		return git__rethrow(error, "Failed to open repository");
 
@@ -78,7 +81,7 @@ static int assign_repository_dirs(
 	if (git_object_directory == NULL)
 		git__joinpath(path_aux, repo->path_repository, GIT_OBJECTS_DIR);
 	else {
-		error = gitfo_prettify_dir_path(path_aux, sizeof(path_aux), git_object_directory);
+		error = gitfo_prettify_dir_path(path_aux, sizeof(path_aux), git_object_directory, NULL);
 		if (error < GIT_SUCCESS)
 			return git__rethrow(error, "Failed to open repository");
 	}
@@ -92,7 +95,7 @@ static int assign_repository_dirs(
 	if (git_work_tree == NULL)
 		repo->is_bare = 1;
 	else {
-		error = gitfo_prettify_dir_path(path_aux, sizeof(path_aux), git_work_tree);
+		error = gitfo_prettify_dir_path(path_aux, sizeof(path_aux), git_work_tree, NULL);
 		if (error < GIT_SUCCESS)
 			return git__rethrow(error, "Failed to open repository");
 
@@ -105,7 +108,7 @@ static int assign_repository_dirs(
 		if (git_index_file == NULL)
 			git__joinpath(path_aux, repo->path_repository, GIT_INDEX_FILE);
 		else {
-			error = gitfo_prettify_file_path(path_aux, sizeof(path_aux), git_index_file);
+			error = gitfo_prettify_file_path(path_aux, sizeof(path_aux), git_index_file, NULL);
 			if (error < GIT_SUCCESS)
 				return git__rethrow(error, "Failed to open repository");
 		}
@@ -268,6 +271,21 @@ cleanup:
 	return git__rethrow(error, "Failed to open repository");
 }
 
+static int discover_repository_dirs(git_repository *repo, const char *path)
+{
+	int error;
+
+	error = guess_repository_dirs(repo, path);
+	if (error < GIT_SUCCESS)
+		return error;
+
+	error = check_repository_dirs(repo);
+	if (error < GIT_SUCCESS)
+		return error;
+
+	return GIT_SUCCESS;
+}
+
 int git_repository_open(git_repository **repo_out, const char *path)
 {
 	git_repository *repo;
@@ -279,11 +297,7 @@ int git_repository_open(git_repository **repo_out, const char *path)
 	if (repo == NULL)
 		return GIT_ENOMEM;
 
-	error = guess_repository_dirs(repo, path);
-	if (error < GIT_SUCCESS)
-		goto cleanup;
-
-	error = check_repository_dirs(repo);
+	error = discover_repository_dirs(repo, path);
 	if (error < GIT_SUCCESS)
 		goto cleanup;
 
@@ -299,18 +313,137 @@ cleanup:
 	return git__rethrow(error, "Failed to open repository");
 }
 
-void git_repository_free(git_repository *repo)
+static int abspath(char *buffer_out, size_t size, const char *path)
 {
-	if (repo == NULL)
-		return;
+	assert(buffer_out && size >= GIT_PATH_MAX);
 
-	git_cache_free(&repo->objects);
-	git_repository__refcache_free(&repo->references);
+	#ifdef GIT_WIN32
+		if (_fullpath(buffer_out, path, size) == NULL)
+			return git__throw(GIT_EOSERR, "Failed to retrieve real path: %s causing errors", buffer_out);
+	#else
+		if (realpath(path, buffer_out) == NULL)
+			return git__throw(GIT_EOSERR, "Failed to retrieve real path: %s causing errors", buffer_out);
+	#endif
+
+	gitfo_posixify_path(buffer_out);
+
+	return GIT_SUCCESS;
+}
+
+static dev_t retrieve_device(dev_t *device_out, const char *path)
+{
+	struct stat path_info;
+
+	assert(device_out);
+
+	if (gitfo_stat(path, &path_info))
+		return git__throw(GIT_EOSERR, "Failed to get file informations: %s", path);
+
+	*device_out = path_info.st_dev;
+
+	return GIT_SUCCESS;
+}
+
+static int retrieve_ceiling_directories_offset(const char *path, const char *ceiling_directories)
+{
+	char buf[GIT_PATH_MAX + 1];
+	char buf2[GIT_PATH_MAX + 1];
+	const char *ceil, *sep;
+	int len, max_len = -1;
+	int min_len;
+
+	assert(path);
+
+	min_len = gitfo_retrieve_path_root_offset(path) + 1;
+
+	if (ceiling_directories == NULL || min_len == 0)
+		return min_len;
+
+	for (sep = ceil = ceiling_directories; *sep; ceil = sep + 1) {
+		for (sep = ceil; *sep && *sep != GIT_PATH_LIST_SEPARATOR; sep++);
+		len = sep - ceil;
+
+		if (len == 0 || len > GIT_PATH_MAX || gitfo_retrieve_path_root_offset(ceil) == -1)
+			continue;
+
+		strncpy(buf, ceil, len);
+		buf[len] = '\0';
+
+		gitfo_posixify_path(buf);
+		if (gitfo_prettify_dir_path(buf2, sizeof(buf2), buf, NULL) < GIT_SUCCESS)
+			continue;
+
+		len = strlen(buf2);
+		if (len > 0 && buf2[len-1] == '/')
+			buf[--len] = '\0';
+
+		if (!strncmp(path, buf2, len) &&
+			path[len] == '/' &&
+			len > max_len)
+		{
+			max_len = len;
+		}
+	}
+
+	return max_len <= min_len ? min_len : max_len;
+}
+
+static int read_gitfile(char *path_out, size_t size, const char *file_path, const char *base_path)
+{
+	gitfo_buf file;
+	int error, end_offset;
+	char *data;
+
+	assert(file_path && path_out && size > 0);
+
+	error = gitfo_read_file(&file, file_path);
+
+	if (error < GIT_SUCCESS)
+		return error;
+
+	data = (char*)(file.data);
+
+	if (git__prefixcmp(data, GIT_FILE_CONTENT_PREFIX)) {
+		gitfo_free_buf(&file);
+		return git__throw(GIT_ENOTFOUND, "Invalid gitfile format `%s`", file_path);
+	}
+
+	end_offset = strlen(data) - 1;
 
+	for (;data[end_offset] != '\r' && data[end_offset] != '\n'; --end_offset);
+	data[end_offset] = '\0';
+
+	if (GIT_FILE_CONTENT_PREFIX_LENGTH == end_offset) {
+		gitfo_free_buf(&file);
+		return git__throw(GIT_ENOTFOUND, "No path in git file `%s`", file_path);
+	}
+
+	error = gitfo_prettify_dir_path(path_out, size, data + GIT_FILE_CONTENT_PREFIX_LENGTH, base_path);
+	gitfo_free_buf(&file);
+
+	return error;
+}
+
+static void git_repository__free_dirs(git_repository *repo)
+{
 	free(repo->path_workdir);
+	repo->path_workdir = NULL;
 	free(repo->path_index);
+	repo->path_index = NULL;
 	free(repo->path_repository);
+	repo->path_repository = NULL;
 	free(repo->path_odb);
+	repo->path_odb = NULL;
+}
+
+void git_repository_free(git_repository *repo)
+{
+	if (repo == NULL)
+		return;
+
+	git_cache_free(&repo->objects);
+	git_repository__refcache_free(&repo->references);
+	git_repository__free_dirs(repo);
 
 	if (repo->db != NULL)
 		git_odb_close(repo->db);
@@ -318,6 +451,119 @@ void git_repository_free(git_repository *repo)
 	free(repo);
 }
 
+int git_repository_discover(char *repository_path, size_t size, const char *start_path, int across_fs, const char *ceiling_dirs)
+{
+	git_repository repo;
+	int error, ceiling_offset;
+	char bare_path[GIT_PATH_MAX];
+	char normal_path[GIT_PATH_MAX];
+	char *found_path;
+	dev_t current_device;
+
+	assert(start_path && repository_path);
+	memset(&repo, 0x0, sizeof(git_repository));
+
+	error = abspath(bare_path, sizeof(bare_path), start_path);
+
+	if (error < GIT_SUCCESS)
+		goto cleanup;
+
+	if (!across_fs) {
+		error = retrieve_device(&current_device, bare_path);
+
+		if (error < GIT_SUCCESS)
+			goto cleanup;
+	}
+
+	ceiling_offset = retrieve_ceiling_directories_offset(bare_path, ceiling_dirs);
+	git__joinpath(normal_path, bare_path, DOT_GIT);
+
+	while(1){
+		//look for .git file
+		if (gitfo_isfile(normal_path) == GIT_SUCCESS) {
+			error = read_gitfile(repository_path, size, normal_path, bare_path);
+
+			if (error < GIT_SUCCESS) {
+				git__rethrow(error, "Unable to read git file `%s`", normal_path);
+				goto cleanup;
+			}
+
+			error = discover_repository_dirs(&repo, repository_path);
+			if (error < GIT_SUCCESS)
+				goto cleanup;
+
+			git_repository__free_dirs(&repo);
+
+			return GIT_SUCCESS;
+		}
+
+		//look for .git repository
+		error = discover_repository_dirs(&repo, normal_path);
+		if (error < GIT_SUCCESS && error != GIT_ENOTAREPO)
+			goto cleanup;
+
+		if (error == GIT_SUCCESS) {
+			found_path = normal_path;
+			break;
+		}
+
+		git_repository__free_dirs(&repo);
+
+		//look for bare repository in current directory
+		error = discover_repository_dirs(&repo, bare_path);
+		if (error < GIT_SUCCESS && error != GIT_ENOTAREPO)
+			goto cleanup;
+
+		if (error == GIT_SUCCESS) {
+			found_path = bare_path;
+			break;
+		}
+
+		git_repository__free_dirs(&repo);
+
+		//nothing has been found, lets try the parent directory
+		if (bare_path[ceiling_offset] == '\0') {
+			error = git__throw(GIT_ENOTAREPO,"Not a git repository (or any of the parent directories): %s", start_path);
+			goto cleanup;
+		}
+
+		if (git__dirname_r(normal_path, sizeof(normal_path), bare_path) < GIT_SUCCESS)
+			goto cleanup;
+
+		if (!across_fs) {
+			dev_t new_device;
+			error = retrieve_device(&new_device, normal_path);
+
+			if (error < GIT_SUCCESS)
+				goto cleanup;
+
+			if (current_device != new_device) {
+				error = git__throw(GIT_ENOTAREPO,"Not a git repository (or any parent up to mount parent %s)\n"
+					"Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM_ENVIRONMENT not set).", bare_path);
+				goto cleanup;
+			}
+			current_device = new_device;
+		}
+
+		strcpy(bare_path, normal_path);
+		git__joinpath(normal_path, bare_path, DOT_GIT);
+	}
+
+	if (size < (strlen(found_path) + 1) * sizeof(char)) {
+		error = git__throw(GIT_EOVERFLOW, "The repository buffer is not long enough to handle the repository path `%s`", found_path);
+		goto cleanup;
+	}
+
+	strcpy(repository_path, found_path);
+	git_repository__free_dirs(&repo);
+
+	return GIT_SUCCESS;
+
+	cleanup:
+		git_repository__free_dirs(&repo);
+		return git__rethrow(error, "Failed to discover repository");
+}
+
 git_odb *git_repository_database(git_repository *repo)
 {
 	assert(repo);
@@ -390,7 +636,7 @@ static int repo_init_find_dir(repo_init *results, const char* path)
 	char temp_path[GIT_PATH_MAX];
 	int error = GIT_SUCCESS;
 
-	error = gitfo_prettify_dir_path(temp_path, sizeof(temp_path), path);
+	error = gitfo_prettify_dir_path(temp_path, sizeof(temp_path), path, NULL);
 	if (error < GIT_SUCCESS)
 		return git__rethrow(error, "Failed to find directory to initialize repository");
 
diff --git a/src/sha1_lookup.c b/src/sha1_lookup.c
index f4a3c42cc..6ac00c5aa 100644
--- a/src/sha1_lookup.c
+++ b/src/sha1_lookup.c
@@ -97,7 +97,7 @@ int sha1_entry_pos(const void *table,
 		   unsigned lo, unsigned hi, unsigned nr,
 		   const unsigned char *key)
 {
-	const unsigned char *base = table;
+	const unsigned char *base = (const unsigned char*)table;
 	const unsigned char *hi_key, *lo_key;
 	unsigned ofs_0;
 
@@ -192,5 +192,5 @@ int sha1_entry_pos(const void *table,
 			lo_key = mi_key + elem_size;
 		}
 	} while (lo < hi);
-	return -lo-1;
+	return -((int)lo)-1;
 }