commit 9f5da0913af47a525ab2a2422c7911cdb08866d0
from: Tom Jones <thj@freebsd.org>
via: tj <tj@enoti.me>
date: Mon Oct 10 12:44:37 2022 UTC

diff: Add API for consumers to check if diff is printable

Programs using the libdiff API they can need to know if the diff
contained anything that would be printed, or would be empty.

Expose the same check that the output functions do as a function call.

ok stsp@

commit - e1595dc1c75393361878450cc70fcefee131810a
commit + 9f5da0913af47a525ab2a2422c7911cdb08866d0
blob - 5e816ae10b5948c0aeacd27365a91f3147b96baf
blob + fa9dc982956eab298f65b4b9ffca114a46b50b76
--- include/diff_main.h
+++ include/diff_main.h
@@ -251,3 +251,4 @@ struct diff_result *diff_main(const struct diff_config
 			      struct diff_data *left,
 			      struct diff_data *right);
 void diff_result_free(struct diff_result *result);
+int diff_result_contains_printable_chunks(struct diff_result *result);
blob - c531ad29bc45c650dd4e3dbc4773479aafd7676b
blob + 325830b65763ecd28f365b69cfc7091b6445971f
--- lib/diff_main.c
+++ lib/diff_main.c
@@ -627,4 +627,20 @@ diff_result_free(struct diff_result *result)
 		return;
 	ARRAYLIST_FREE(result->chunks);
 	free(result);
+}
+
+int
+diff_result_contains_printable_chunks(struct diff_result *result)
+{
+	struct diff_chunk *c;
+	enum diff_chunk_type t;
+
+	for (int i = 0; i < result->chunks.len; i++) {
+		c = &result->chunks.head[i];
+		t = diff_chunk_type(c);
+		if (t == CHUNK_MINUS || t == CHUNK_PLUS)
+			return 1;
+	}
+
+	return 0;
 }