Sync operation doesn't remove pattern when source is empty

[cottsay]

When performing a --sync operation from another repository, there's a "shortcut" in the logic which returns early if there were no packages found in the source repository matching the sync pattern. While this makes some sense, the result is that the pattern-based invalidation which would have removed all packages from the downstream repository matching the pattern doesn't occur.

createrepo-agent/src/createrepo-agent/command.c

Lines 390 to 403 in 70fffe4

	if (pattern) {
	g_hash_table_iter_init(&iter, packages);
	while (g_hash_table_iter_next(&iter, NULL, (gpointer *)&package)) {
	if (!g_regex_match(pattern, package->name, 0, NULL)) {
	g_hash_table_iter_remove(&iter);
	}
	}
	}
	if (!g_hash_table_size(packages)) {
	g_string_free(url, TRUE);
	cr_metadata_free(md);
	return CRE_OK;
	}