Diff iterators

This refactors the diff output code so that an iterator object
can be used to traverse and generate the diffs, instead of just
the `foreach()` style with callbacks.  The code has been rearranged
so that the two styles can still share most functions.

This also replaces `GIT_REVWALKOVER` with `GIT_ITEROVER` and uses
that as a common error code for marking the end of iteration when
using a iterator style of object.

1 files changed, 116 insertions, 0 deletions

diff --git a/tests-clar/diff/diffiter.c b/tests-clar/diff/diffiter.c
new file mode 100644
index 00000000..56c25474
--- /dev/null
+++ b/tests-clar/diff/diffiter.c
@@ -0,0 +1,116 @@
+#include "clar_libgit2.h"
+#include "diff_helpers.h"
+
+void test_diff_diffiter__initialize(void)
+{
+}
+
+void test_diff_diffiter__cleanup(void)
+{
+	cl_git_sandbox_cleanup();
+}
+
+void test_diff_diffiter__create(void)
+{
+	git_repository *repo = cl_git_sandbox_init("attr");
+	git_diff_list *diff;
+	git_diff_iterator *iter;
+
+	cl_git_pass(git_diff_workdir_to_index(repo, NULL, &diff));
+	cl_git_pass(git_diff_iterator_new(&iter, diff));
+	git_diff_iterator_free(iter);
+	git_diff_list_free(diff);
+}
+
+void test_diff_diffiter__iterate_files(void)
+{
+	git_repository *repo = cl_git_sandbox_init("attr");
+	git_diff_list *diff;
+	git_diff_iterator *iter;
+	git_diff_delta *delta;
+	int error, count = 0;
+
+	cl_git_pass(git_diff_workdir_to_index(repo, NULL, &diff));
+	cl_git_pass(git_diff_iterator_new(&iter, diff));
+
+	while ((error = git_diff_iterator_next_file(&delta, iter)) != GIT_ITEROVER) {
+		cl_assert_equal_i(0, error);
+		cl_assert(delta != NULL);
+		count++;
+	}
+
+	cl_assert_equal_i(GIT_ITEROVER, error);
+	cl_assert(delta == NULL);
+	cl_assert_equal_i(6, count);
+
+	git_diff_iterator_free(iter);
+	git_diff_list_free(diff);
+}
+
+void test_diff_diffiter__iterate_files_2(void)
+{
+	git_repository *repo = cl_git_sandbox_init("status");
+	git_diff_list *diff;
+	git_diff_iterator *iter;
+	git_diff_delta *delta;
+	int error, count = 0;
+
+	cl_git_pass(git_diff_workdir_to_index(repo, NULL, &diff));
+	cl_git_pass(git_diff_iterator_new(&iter, diff));
+
+	while ((error = git_diff_iterator_next_file(&delta, iter)) != GIT_ITEROVER) {
+		cl_assert_equal_i(0, error);
+		cl_assert(delta != NULL);
+		count++;
+	}
+
+	cl_assert_equal_i(GIT_ITEROVER, error);
+	cl_assert(delta == NULL);
+	cl_assert_equal_i(8, count);
+
+	git_diff_iterator_free(iter);
+	git_diff_list_free(diff);
+}
+
+void test_diff_diffiter__iterate_files_and_hunks(void)
+{
+	git_repository *repo = cl_git_sandbox_init("status");
+	git_diff_options opts = {0};
+	git_diff_list *diff = NULL;
+	git_diff_iterator *iter;
+	git_diff_delta *delta;
+	git_diff_range *range;
+	const char *header;
+	size_t header_len;
+	int error, file_count = 0, hunk_count = 0;
+
+	opts.context_lines = 3;
+	opts.interhunk_lines = 1;
+	opts.flags |= GIT_DIFF_INCLUDE_IGNORED | GIT_DIFF_INCLUDE_UNTRACKED;
+
+	cl_git_pass(git_diff_workdir_to_index(repo, &opts, &diff));
+
+	cl_git_pass(git_diff_iterator_new(&iter, diff));
+
+	while ((error = git_diff_iterator_next_file(&delta, iter)) != GIT_ITEROVER) {
+		cl_assert_equal_i(0, error);
+		cl_assert(delta);
+
+		file_count++;
+
+		while ((error = git_diff_iterator_next_hunk(
+				&range, &header, &header_len, iter)) != GIT_ITEROVER) {
+			cl_assert_equal_i(0, error);
+			cl_assert(range);
+			hunk_count++;
+		}
+	}
+
+	cl_assert_equal_i(GIT_ITEROVER, error);
+	cl_assert(delta == NULL);
+	cl_assert_equal_i(13, file_count);
+	cl_assert_equal_i(8, hunk_count);
+
+	git_diff_iterator_free(iter);
+	git_diff_list_free(diff);
+}