Fix iterators based on pull request feedback

This update addresses all of the feedback in pull request #570.

The biggest change was to create actual linked list stacks for
storing the tree and workdir iterator state.  This cleaned up
the code a ton.  Additionally, all of the static functions had
their 'git_' prefix removed, and a lot of other unnecessary
changes were removed from the original patch.

src/ignore.c

@@ -147,7 +147,7 @@ int git_ignore__pop_dir(git_ignores *ign)
 	if (ign->ign_path.length > 0) {
 		git_attr_file *file = git_vector_last(&ign->ign_path);
 		if (git__suffixcmp(ign->dir.ptr, file->path) == 0)
-			git_vector_pop(&ign->ign_path, NULL);
+			git_vector_pop(&ign->ign_path);
 		git_buf_rtruncate_at_char(&ign->dir, '/');
 	}
 	return GIT_SUCCESS;

src/path.c

@@ -398,42 +398,38 @@ int git_path_isfile(const char *path)
 static int _check_dir_contents(
 	git_buf *dir,
 	const char *sub,
-	int append_on_success,
 	int (*predicate)(const char *))
 {
 	int error = GIT_SUCCESS;
 	size_t dir_size = dir->size;
 	size_t sub_size = strlen(sub);
 
-	/* leave base valid even if we could not make space for subdir */
+	/* separate allocation and join, so we can always leave git_buf valid */
 	if ((error = git_buf_try_grow(dir, dir_size + sub_size + 2)) < GIT_SUCCESS)
 		return error;
-
-	/* save excursion */
 	git_buf_joinpath(dir, dir->ptr, sub);
 
 	error = (*predicate)(dir->ptr);
 
-	/* restore excursion */
-	if (!append_on_success || error != GIT_SUCCESS)
-		git_buf_truncate(dir, dir_size);
+	/* restore path */
+	git_buf_truncate(dir, dir_size);
 
 	return error;
 }
 
 int git_path_contains(git_buf *dir, const char *item)
 {
-	return _check_dir_contents(dir, item, 0, &git_path_exists);
+	return _check_dir_contents(dir, item, &git_path_exists);
 }
 
-int git_path_contains_dir(git_buf *base, const char *subdir, int append_if_exists)
+int git_path_contains_dir(git_buf *base, const char *subdir)
 {
-	return _check_dir_contents(base, subdir, append_if_exists, &git_path_isdir);
+	return _check_dir_contents(base, subdir, &git_path_isdir);
 }
 
-int git_path_contains_file(git_buf *base, const char *file, int append_if_exists)
+int git_path_contains_file(git_buf *base, const char *file)
 {
-	return _check_dir_contents(base, file, append_if_exists, &git_path_isfile);
+	return _check_dir_contents(base, file, &git_path_isfile);
 }
 
 int git_path_find_dir(git_buf *dir, const char *path, const char *base)

src/path.h

@@ -143,20 +143,18 @@ extern int git_path_contains(git_buf *dir, const char *item);
  *
  * @param parent Directory path that might contain subdir
  * @param subdir Subdirectory name to look for in parent
- * @param append_if_exists If true, then subdir will be appended to the parent path if it does exist
  * @return GIT_SUCCESS if subdirectory exists, < 0 otherwise.
  */
-extern int git_path_contains_dir(git_buf *parent, const char *subdir, int append_if_exists);
+extern int git_path_contains_dir(git_buf *parent, const char *subdir);
 
 /**
  * Check if the given path contains the given file.
  *
  * @param dir Directory path that might contain file
  * @param file File name to look for in parent
- * @param append_if_exists If true, then file will be appended to the path if it does exist
  * @return GIT_SUCCESS if file exists, < 0 otherwise.
  */
-extern int git_path_contains_file(git_buf *dir, const char *file, int append_if_exists);
+extern int git_path_contains_file(git_buf *dir, const char *file);
 
 /**
  * Clean up path, prepending base if it is not already rooted.

src/repository.c

@@ -81,14 +81,14 @@ void git_repository_free(git_repository *repo)
 static int quickcheck_repository_dir(git_buf *repository_path)
 {
 	/* Check OBJECTS_DIR first, since it will generate the longest path name */
-	if (git_path_contains_dir(repository_path, GIT_OBJECTS_DIR, 0) < 0)
+	if (git_path_contains_dir(repository_path, GIT_OBJECTS_DIR) < 0)
 		return GIT_ERROR;
 
 	/* Ensure HEAD file exists */
-	if (git_path_contains_file(repository_path, GIT_HEAD_FILE, 0) < 0)
+	if (git_path_contains_file(repository_path, GIT_HEAD_FILE) < 0)
 		return GIT_ERROR;
 
-	if (git_path_contains_dir(repository_path, GIT_REFS_DIR, 0) < 0)
+	if (git_path_contains_dir(repository_path, GIT_REFS_DIR) < 0)
 		return GIT_ERROR;
 
 	return GIT_SUCCESS;
@@ -166,8 +166,8 @@ int git_repository_open(git_repository **repo_out, const char *path)
 	 * of the working dir, by testing if it contains a `.git`
 	 * folder inside of it.
 	 */
-	git_path_contains_dir(&path_buf, GIT_DIR, 1); /* append on success */
-	/* ignore error, since it just means `path/.git` doesn't exist */
+	if (git_path_contains_dir(&path_buf, GIT_DIR) == GIT_SUCCESS)
+		git_buf_joinpath(&path_buf, path_buf.ptr, GIT_DIR);
 
 	if (quickcheck_repository_dir(&path_buf) < GIT_SUCCESS) {
 		error = git__throw(GIT_ENOTAREPO,

src/vector.c

@@ -25,24 +25,6 @@ static int resize_vector(git_vector *v)
 	return GIT_SUCCESS;
 }
 
-int git_vector_alloc(
-	git_vector **vptr, unsigned int initial_size, git_vector_cmp cmp)
-{
-	int error;
-	git_vector *v = git__malloc(sizeof(git_vector));
-	if (!v) {
-		*vptr = NULL;
-		return GIT_ENOMEM;
-	}
-
-	if ((error = git_vector_init(v, initial_size, cmp)) < GIT_SUCCESS) {
-		git__free(v);
-		v = NULL;
-	}
-	*vptr = v;
-	return error;
-}
-
 void git_vector_free(git_vector *v)
 {
 	assert(v);
@@ -205,19 +187,10 @@ int git_vector_remove(git_vector *v, unsigned int idx)
 	return GIT_SUCCESS;
 }
 
-int git_vector_pop(git_vector *v, void **element)
+void git_vector_pop(git_vector *v)
 {
-	assert(v);
-
-	if (v->length == 0)
-		return git__throw(GIT_ENOTFOUND, "Can't remove element from empty list");
-
-	if (element != NULL)
-		*element = v->contents[v->length - 1];
-
-	v->length--;
-
-	return GIT_SUCCESS;
+	if (v->length > 0)
+		v->length--;
 }
 
 void git_vector_uniq(git_vector *v)

src/vector.h

@@ -22,7 +22,6 @@ typedef struct git_vector {
 #define GIT_VECTOR_INIT {0}
 
 int git_vector_init(git_vector *v, unsigned int initial_size, git_vector_cmp cmp);
-int git_vector_alloc(git_vector **v, unsigned int initial_size, git_vector_cmp cmp);
 void git_vector_free(git_vector *v);
 void git_vector_clear(git_vector *v);
 
@@ -54,7 +53,7 @@ int git_vector_insert(git_vector *v, void *element);
 int git_vector_insert_sorted(git_vector *v, void *element,
 	int (*on_dup)(void **old, void *new));
 int git_vector_remove(git_vector *v, unsigned int idx);
-int git_vector_pop(git_vector *v, void **element);
+void git_vector_pop(git_vector *v);
 void git_vector_uniq(git_vector *v);
 
 #endif