Fix iterator reset and add reset ranges

The `git_iterator_reset` command has not been working in all cases
particularly when there is a start and end range.  This fixes it
and adds tests for it, and also extends it with the ability to
update the start/end range strings when an iterator is reset.

src/iterator.h

@@ -37,7 +37,7 @@ struct git_iterator {
 	int (*at_end)(git_iterator *);
 	int (*advance)(git_iterator *, const git_index_entry **);
 	int (*seek)(git_iterator *, const char *prefix);
-	int (*reset)(git_iterator *);
+	int (*reset)(git_iterator *, const char *start, const char *end);
 	void (*free)(git_iterator *);
 };
 
@@ -126,9 +126,10 @@ GIT_INLINE(int) git_iterator_seek(
 	return iter->seek(iter, prefix);
 }
 
-GIT_INLINE(int) git_iterator_reset(git_iterator *iter)
+GIT_INLINE(int) git_iterator_reset(
+	git_iterator *iter, const char *start, const char *end)
 {
-	return iter->reset(iter);
+	return iter->reset(iter, start, end);
 }
 
 GIT_INLINE(void) git_iterator_free(git_iterator *iter)

src/path.c

@@ -770,18 +770,30 @@ int git_path_dirload(
 int git_path_with_stat_cmp(const void *a, const void *b)
 {
 	const git_path_with_stat *psa = a, *psb = b;
-	return git__strcmp_cb(psa->path, psb->path);
+	return strcmp(psa->path, psb->path);
+}
+
+int git_path_with_stat_cmp_icase(const void *a, const void *b)
+{
+	const git_path_with_stat *psa = a, *psb = b;
+	return strcasecmp(psa->path, psb->path);
 }
 
 int git_path_dirload_with_stat(
 	const char *path,
 	size_t prefix_len,
+	bool ignore_case,
+	const char *start_stat,
+	const char *end_stat,
 	git_vector *contents)
 {
 	int error;
 	unsigned int i;
 	git_path_with_stat *ps;
 	git_buf full = GIT_BUF_INIT;
+	int (*strncomp)(const char *a, const char *b, size_t sz);
+	size_t start_len = start_stat ? strlen(start_stat) : 0;
+	size_t end_len = end_stat ? strlen(end_stat) : 0, cmp_len;
 
 	if (git_buf_set(&full, path, prefix_len) < 0)
 		return -1;
@@ -793,11 +805,23 @@ int git_path_dirload_with_stat(
 		return error;
 	}
 
+	strncomp = ignore_case ? git__strncasecmp : git__strncmp;
+
+	/* stat struct at start of git_path_with_stat, so shift path text */
 	git_vector_foreach(contents, i, ps) {
 		size_t path_len = strlen((char *)ps);
-
 		memmove(ps->path, ps, path_len + 1);
 		ps->path_len = path_len;
+	}
+
+	git_vector_foreach(contents, i, ps) {
+		/* skip if before start_stat or after end_stat */
+		cmp_len = min(start_len, ps->path_len);
+		if (cmp_len && strncomp(ps->path, start_stat, cmp_len) < 0)
+			continue;
+		cmp_len = min(end_len, ps->path_len);
+		if (cmp_len && strncomp(ps->path, end_stat, cmp_len) > 0)
+			continue;
 
 		if ((error = git_buf_joinpath(&full, full.ptr, ps->path)) < 0 ||
 			(error = git_path_lstat(full.ptr, &ps->st)) < 0)
@@ -806,11 +830,14 @@ int git_path_dirload_with_stat(
 		git_buf_truncate(&full, prefix_len);
 
 		if (S_ISDIR(ps->st.st_mode)) {
-			ps->path[path_len] = '/';
-			ps->path[path_len + 1] = '\0';
+			ps->path[ps->path_len++] = '/';
+			ps->path[ps->path_len] = '\0';
 		}
 	}
 
+	/* sort now that directory suffix is added */
+	git_vector_sort(contents);
+
 	git_buf_free(&full);
 
 	return error;

src/path.h

@@ -321,18 +321,33 @@ typedef struct {
 } git_path_with_stat;
 
 extern int git_path_with_stat_cmp(const void *a, const void *b);
+extern int git_path_with_stat_cmp_icase(const void *a, const void *b);
 
 /**
  * Load all directory entries along with stat info into a vector.
  *
- * This is just like git_path_dirload except that each entry in the
- * vector is a git_path_with_stat structure that contains both the
- * path and the stat info, plus directories will have a / suffixed
- * to their path name.
+ * This adds four things on top of plain `git_path_dirload`:
+ *
+ * 1. Each entry in the vector is a `git_path_with_stat` struct that
+ *    contains both the path and the stat info
+ * 2. The entries will be sorted alphabetically
+ * 3. Entries that are directories will be suffixed with a '/'
+ * 4. Optionally, you can be a start and end prefix and only elements
+ *    after the start and before the end (inclusively) will be stat'ed.
+ *
+ * @param path The directory to read from
+ * @param prefix_len The trailing part of path to prefix to entry paths
+ * @param ignore_case How to sort and compare paths with start/end limits
+ * @param start_stat As optimization, only stat values after this prefix
+ * @param end_stat As optimization, only stat values before this prefix
+ * @param contents Vector to fill with git_path_with_stat structures
  */
 extern int git_path_dirload_with_stat(
 	const char *path,
 	size_t prefix_len,
+	bool ignore_case,
+	const char *start_stat,
+	const char *end_stat,
 	git_vector *contents);
 
 #endif

src/tree.c

@@ -301,6 +301,9 @@ int git_tree__prefix_position(git_tree *tree, const char *path)
 	struct tree_key_search ksearch;
 	size_t at_pos;
 
+	if (!path)
+		return 0;
+
 	ksearch.filename = path;
 	ksearch.filename_len = strlen(path);
 

src/tree.h

@@ -29,6 +29,10 @@ struct git_treebuilder {
 	git_vector entries;
 };
 
+GIT_INLINE(int) git_tree__dup(git_tree **dest, git_tree *source)
+{
+	return git_object__dup((git_object **)dest, (git_object *)source);
+}
 
 GIT_INLINE(bool) git_tree_entry__is_tree(const struct git_tree_entry *e)
 {

src/util.c

@@ -199,9 +199,17 @@ int git__strncmp(const char *a, const char *b, size_t sz)
 
 int git__strncasecmp(const char *a, const char *b, size_t sz)
 {
-	while (sz && *a && *b && tolower(*a) == tolower(*b))
+	int al, bl;
+
+	while (sz && *a && *b) {
+		al = (unsigned char)tolower(*a);
+		bl = (unsigned char)tolower(*b);
+		if (al != bl)
+			break;
 		--sz, ++a, ++b;
-	return !sz ? 0 : (tolower(*a) - tolower(*b));
+	}
+
+	return !sz ? 0 : al - bl;
 }
 
 void git__strntolower(char *str, size_t len)

tests-clar/diff/iterator.c

@@ -31,25 +31,35 @@ static void tree_iterator_test(
 	git_tree *t;
 	git_iterator *i;
 	const git_index_entry *entry;
-	int count = 0;
+	int count = 0, count_post_reset = 0;
 	git_repository *repo = cl_git_sandbox_init(sandbox);
 
 	cl_assert(t = resolve_commit_oid_to_tree(repo, treeish));
 	cl_git_pass(git_iterator_for_tree_range(&i, t, start, end));
-	cl_git_pass(git_iterator_current(i, &entry));
 
+	/* test loop */
+	cl_git_pass(git_iterator_current(i, &entry));
 	while (entry != NULL) {
 		if (expected_values != NULL)
 			cl_assert_equal_s(expected_values[count], entry->path);
-
 		count++;
+		cl_git_pass(git_iterator_advance(i, &entry));
+	}
 
+	/* test reset */
+	cl_git_pass(git_iterator_reset(i, NULL, NULL));
+	cl_git_pass(git_iterator_current(i, &entry));
+	while (entry != NULL) {
+		if (expected_values != NULL)
+			cl_assert_equal_s(expected_values[count_post_reset], entry->path);
+		count_post_reset++;
 		cl_git_pass(git_iterator_advance(i, &entry));
 	}
 
 	git_iterator_free(i);
 
-	cl_assert(expected_count == count);
+	cl_assert_equal_i(expected_count, count);
+	cl_assert_equal_i(count, count_post_reset);
 
 	git_tree_free(t);
 }
@@ -520,7 +530,7 @@ static void workdir_iterator_test(
 {
 	git_iterator *i;
 	const git_index_entry *entry;
-	int count = 0, count_all = 0;
+	int count = 0, count_all = 0, count_all_post_reset = 0;
 	git_repository *repo = cl_git_sandbox_init(sandbox);
 
 	cl_git_pass(git_iterator_for_workdir_range(&i, repo, start, end));
@@ -547,10 +557,26 @@ static void workdir_iterator_test(
 		cl_git_pass(git_iterator_advance(i, &entry));
 	}
 
+	cl_git_pass(git_iterator_reset(i, NULL, NULL));
+	cl_git_pass(git_iterator_current(i, &entry));
+
+	while (entry != NULL) {
+		if (S_ISDIR(entry->mode)) {
+			cl_git_pass(git_iterator_advance_into_directory(i, &entry));
+			continue;
+		}
+		if (expected_names != NULL)
+			cl_assert_equal_s(
+				expected_names[count_all_post_reset], entry->path);
+		count_all_post_reset++;
+		cl_git_pass(git_iterator_advance(i, &entry));
+	}
+
 	git_iterator_free(i);
 
-	cl_assert_equal_i(expected_count,count);
+	cl_assert_equal_i(expected_count, count);
 	cl_assert_equal_i(expected_count + expected_ignores, count_all);
+	cl_assert_equal_i(count_all, count_all_post_reset);
 }
 
 void test_diff_iterator__workdir_0(void)