Merge branch 'na/notes-displayref-is-not-boolean'

Config parser fix for "git notes".

* na/notes-displayref-is-not-boolean:
  t3301: test proper exit response to no-value notes.displayRef.
  notes.c: fix a segfault in notes_display_config()

notes.c

@@ -970,7 +970,7 @@ static int notes_display_config(const char *k, const char *v, void *cb)
 
 	if (*load_refs && !strcmp(k, "notes.displayref")) {
 		if (!v)
-			config_error_nonbool(k);
+			return config_error_nonbool(k);
 		string_list_add_refs_by_glob(&display_notes_refs, v);
 	}
 

t/t3301-notes.sh

@@ -672,6 +672,11 @@ test_expect_success 'notes.displayRef respects order' '
 	test_cmp expect-both-reversed actual
 '
 
+test_expect_success 'notes.displayRef with no value handled gracefully' '
+	test_must_fail git -c notes.displayRef log -0 --notes &&
+	test_must_fail git -c notes.displayRef diff-tree --notes HEAD
+'
+
 test_expect_success 'GIT_NOTES_DISPLAY_REF works' '
 	GIT_NOTES_DISPLAY_REF=refs/notes/commits:refs/notes/other \
 		git log -2 >actual &&