+/*
+ * Call fn for each reference in the union of array1 and array2, in
+ * order by refname. If an entry appears in both array1 and array2,
+ * then only process the version that is in array2. The input arrays
+ * must already be sorted.
+ */
+static int do_for_each_ref_in_arrays(struct ref_array *array1,
+ struct ref_array *array2,
+ const char *base, each_ref_fn fn, int trim,
+ int flags, void *cb_data)
+{
+ int retval;
+ int i1 = 0, i2 = 0;
+
+ assert(array1->sorted == array1->nr);
+ assert(array2->sorted == array2->nr);
+ while (i1 < array1->nr && i2 < array2->nr) {
+ struct ref_entry *e1 = array1->refs[i1];
+ struct ref_entry *e2 = array2->refs[i2];
+ int cmp = strcmp(e1->name, e2->name);
+ if (cmp < 0) {
+ retval = do_one_ref(base, fn, trim, flags, cb_data, e1);
+ i1++;
+ } else {
+ retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
+ i2++;
+ if (cmp == 0) {
+ /*
+ * There was a ref in array1 with the
+ * same name; ignore it.
+ */
+ i1++;
+ }
+ }
+ if (retval)
+ return retval;
+ }
+ if (i1 < array1->nr)
+ return do_for_each_ref_in_array(array1, i1,
+ base, fn, trim, flags, cb_data);
+ if (i2 < array2->nr)
+ return do_for_each_ref_in_array(array2, i2,
+ base, fn, trim, flags, cb_data);
+ return 0;
+}
+