apply test: apply with non-conflicting changes

Ensure that we can apply to the working directory or the index when the
application target is modified, so long as there are not conflicting
changes to the items.

tests/apply/index.c

@@ -226,3 +226,46 @@ void test_apply_index__application_failure_leaves_index_unmodified(void)
 
 	git_diff_free(diff);
 }
+
+void test_apply_index__keeps_nonconflicting_changes(void)
+{
+	git_diff *diff;
+	git_index *index;
+	git_index_entry idx_entry;
+	git_apply_options opts = GIT_APPLY_OPTIONS_INIT;
+
+	const char *diff_file = DIFF_MODIFY_TWO_FILES;
+
+	struct merge_index_entry index_expected[] = {
+		{ 0100644, "ffb36e513f5fdf8a6ba850a20142676a2ac4807d", 0, "asparagus.txt" },
+		{ 0100644, "898d12687fb35be271c27c795a6b32c8b51da79e", 0, "beef.txt" },
+		{ 0100644, "c4e6cca3ec6ae0148ed231f97257df8c311e015f", 0, "gravy.txt" },
+		{ 0100644, "68af1fc7407fd9addf1701a87eb1c95c7494c598", 0, "oyster.txt" },
+		{ 0100644, "a7b066537e6be7109abfe4ff97b675d4e077da20", 0, "veal.txt" },
+	};
+	size_t index_expected_cnt = sizeof(index_expected) /
+		sizeof(struct merge_index_entry);
+
+	/* mutate the index */
+	cl_git_pass(git_repository_index(&index, repo));
+
+	memset(&idx_entry, 0, sizeof(git_index_entry));
+	idx_entry.mode = 0100644;
+	idx_entry.path = "beef.txt";
+	cl_git_pass(git_oid_fromstr(&idx_entry.id, "898d12687fb35be271c27c795a6b32c8b51da79e"));
+	cl_git_pass(git_index_add(index, &idx_entry));
+
+	cl_git_pass(git_index_remove(index, "bouilli.txt", 0));
+	cl_git_pass(git_index_write(index));
+	git_index_free(index);
+
+	cl_git_pass(git_diff_from_buffer(&diff, diff_file, strlen(diff_file)));
+
+	opts.location = GIT_APPLY_LOCATION_INDEX;
+	cl_git_pass(git_apply(repo, diff, &opts));
+
+	validate_apply_index(repo, index_expected, index_expected_cnt);
+	validate_workdir_unchanged(repo);
+
+	git_diff_free(diff);
+}

tests/apply/workdir.c

@@ -216,3 +216,30 @@ void test_apply_workdir__application_failure_leaves_workdir_unmodified(void)
 
 	git_diff_free(diff);
 }
+
+void test_apply_workdir__keeps_nonconflicting_changes(void)
+{
+	git_diff *diff;
+
+	struct merge_index_entry workdir_expected[] = {
+		{ 0100644, "ffb36e513f5fdf8a6ba850a20142676a2ac4807d", 0, "asparagus.txt" },
+		{ 0100644, "68f6182f4c85d39e1309d97c7e456156dc9c0096", 0, "beef.txt" },
+		{ 0100644, "4b7c5650008b2e747fe1809eeb5a1dde0e80850a", 0, "bouilli.txt" },
+		{ 0100644, "f75ba05f340c51065cbea2e1fdbfe5fe13144c97", 0, "gravy.txt" },
+		{ 0100644, "a7b066537e6be7109abfe4ff97b675d4e077da20", 0, "veal.txt" },
+	};
+	size_t workdir_expected_cnt = sizeof(workdir_expected) /
+	    sizeof(struct merge_index_entry);
+
+	cl_git_rmfile("merge-recursive/oyster.txt");
+	cl_git_rewritefile("merge-recursive/gravy.txt", "Hello, world.\n");
+
+	cl_git_pass(git_diff_from_buffer(&diff,
+		DIFF_MODIFY_TWO_FILES, strlen(DIFF_MODIFY_TWO_FILES)));
+	cl_git_pass(git_apply(repo, diff, NULL));
+
+	validate_index_unchanged(repo);
+	validate_apply_workdir(repo, workdir_expected, workdir_expected_cnt);
+
+	git_diff_free(diff);
+}