Add git_diff_options_init helper

Sometimes the static initializer for git_diff_options cannot be
used and since setting them to all zeroes doesn't actually work
quite right, this adds a new helper for that situation.

This also adds an explicit new value to the submodule settings
options to be used when those enums need static initialization.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/diff.c b/src/diff.c
index 5c89b6e59..d94fb2c74 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -1311,6 +1311,19 @@ int git_diff_tree_to_workdir_with_index(
 	return error;
 }
 
+int git_diff_options_init(git_diff_options *options, unsigned int version)
+{
+	git_diff_options template = GIT_DIFF_OPTIONS_INIT;
+
+	if (version != template.version) {
+		giterr_set(GITERR_INVALID,
+			"Invalid version %d for git_diff_options", (int)version);
+		return -1;
+	}
+
+	memcpy(options, &template, sizeof(*options));
+	return 0;
+}
 
 size_t git_diff_num_deltas(const git_diff *diff)
 {