Add GIT_DIFF_FIND_DELETE_UNMODIFIED flag

When doing copy detection, it is often necessary to include
UNMODIFIED records in the git_diff so they are available as source
records for GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED.  Yet in the final
diff, often you will not want to have these UNMODIFIED records.
This adds a flag which marks these UNMODIFIED records for deletion
from the diff list so they will be removed after the rename detect
phase is over.

1 files changed, 48 insertions, 0 deletions

diff --git a/tests/diff/rename.c b/tests/diff/rename.c
index 7f033936e..e081d616f 100644
--- a/tests/diff/rename.c
+++ b/tests/diff/rename.c
@@ -1333,3 +1333,51 @@ void test_diff_rename__can_find_copy_to_split(void)
 
 	git_buf_free(&c1);
 }
+
+void test_diff_rename__can_delete_unmodified_deltas(void)
+{
+	git_buf c1 = GIT_BUF_INIT;
+	git_index *index;
+	git_tree *tree;
+	git_diff *diff;
+	git_diff_options diffopts = GIT_DIFF_OPTIONS_INIT;
+	git_diff_find_options opts = GIT_DIFF_FIND_OPTIONS_INIT;
+	diff_expects exp;
+
+	cl_git_pass(git_futils_readbuffer(&c1, "renames/songof7cities.txt"));
+	cl_git_pass(git_futils_writebuffer(&c1, "renames/untimely.txt", 0, 0));
+
+	cl_git_pass(
+		git_revparse_single((git_object **)&tree, g_repo, "HEAD^{tree}"));
+
+	cl_git_pass(git_repository_index(&index, g_repo));
+	cl_git_pass(git_index_read_tree(index, tree));
+	cl_git_pass(git_index_add_bypath(index, "untimely.txt"));
+
+	diffopts.flags = GIT_DIFF_INCLUDE_UNMODIFIED;
+
+	cl_git_pass(git_diff_tree_to_index(&diff, g_repo, tree, index, &diffopts));
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff, diff_file_cb, diff_hunk_cb, diff_line_cb, &exp));
+	cl_assert_equal_i(4, exp.files);
+	cl_assert_equal_i(1, exp.file_status[GIT_DELTA_MODIFIED]);
+	cl_assert_equal_i(3, exp.file_status[GIT_DELTA_UNMODIFIED]);
+
+	opts.flags = GIT_DIFF_FIND_ALL | GIT_DIFF_FIND_DELETE_UNMODIFIED;
+	cl_git_pass(git_diff_find_similar(diff, &opts));
+
+	memset(&exp, 0, sizeof(exp));
+	cl_git_pass(git_diff_foreach(
+		diff, diff_file_cb, diff_hunk_cb, diff_line_cb, &exp));
+	cl_assert_equal_i(2, exp.files);
+	cl_assert_equal_i(1, exp.file_status[GIT_DELTA_DELETED]);
+	cl_assert_equal_i(1, exp.file_status[GIT_DELTA_COPIED]);
+
+	git_diff_free(diff);
+	git_tree_free(tree);
+	git_index_free(index);
+
+	git_buf_free(&c1);
+}