commit cb63de52eb578c78c4c4cff41b6494019e3b5c3f
from: James Cook <falsifian@falsifian.org>
via: Thomas Adam <thomas@xteddy.org>
date: Thu Sep 21 14:53:04 2023 UTC

in diff error message, say what was being diffed

When trying to run "got ci" adding a large file, this changes the
following error message:
	got: diff_atomize_file: Cannot allocate memory
into:
	got: /dev/null vs /path/to/the/really/big/file: diff_atomize_file: Cannot allocate memory

ok stsp@

commit - 4fca09464de0b3459fa7942804c07e4064481fa0
commit + cb63de52eb578c78c4c4cff41b6494019e3b5c3f
blob - 96736bcee618adc7c0693f929dd038909bdeda1d
blob + aa67f591fb351d377bca13b28e1dc0b7296e8a96
--- lib/diff.c
+++ lib/diff.c
@@ -378,8 +378,15 @@ diff_blob_file(struct got_diffreg_result **resultp,
 
 	err = got_diffreg(&result, f1, f2, diff_algo, ignore_whitespace,
 	    force_text_diff);
-	if (err)
+	if (err) {
+		char msg[GOT_ERR_MAX_MSG_SIZE];
+		if (snprintf(msg, sizeof(msg), "%s vs %s: %s",
+		             label1 ? label1 : idstr1,
+		             f2_exists ? label2 : "/dev/null", err->msg) >= 0) {
+			err = got_error_msg(err->code, msg);
+		}
 		goto done;
+	}
 
 	if (outfile) {
 		err = got_diffreg_output(NULL, NULL, result,