Extensively verified that all functions have its return value

checked for any spurious error, this should make the core more safer :-)

--HG--
extra : convert_revision : xtraeme%40gmail.com-20091123094651-5prw0bkqmt3y8h23

lib/remove.c

@@ -101,7 +101,12 @@ files:
 			prop_object_iterator_release(iter);
 			return EINVAL;
 		}
-		prop_dictionary_get_cstring_nocopy(obj, "sha256", &sha256);
+		if (!prop_dictionary_get_cstring_nocopy(obj,
+		    "sha256", &sha256)) {
+			prop_object_iterator_release(iter);
+			free(path);
+			return errno;
+		}
 		rv = xbps_check_file_hash(path, sha256);
 		if (rv == ENOENT) {
 			printf("WARNING: '%s' doesn't exist!\n", file);