bus-error: verify additional error maps during installation

Go over the entries in the map and check that they make sense.
Tests are added. In the future we might want to do additional
checks, e.g. verifying that the error names are in the expected
format.

diff --git a/src/libelogind/sd-bus/bus-error.c b/src/libelogind/sd-bus/bus-error.c
index a99d55c47ab9db585fef4aff2aa2c574a2dacc82..c77eb5fd0381517f94d566cc663a5d50df9c4848 100644 (file)
--- a/src/libelogind/sd-bus/bus-error.c
+++ b/src/libelogind/sd-bus/bus-error.c
@@ -579,27 +579,29 @@ const char *bus_error_message(const sd_bus_error *e, int error) {
         return strerror(error);
 }
 
+static bool map_ok(const sd_bus_error_map *map) {
+        for (; map->code != BUS_ERROR_MAP_END_MARKER; map++)
+                if (!map->name || map->code <=0)
+                        return false;
+        return true;
+}
+
 _public_ int sd_bus_error_add_map(const sd_bus_error_map *map) {
         const sd_bus_error_map **maps = NULL;
         unsigned n = 0;
 
         assert_return(map, -EINVAL);
+        assert_return(map_ok(map), -EINVAL);
 
-        if (additional_error_maps) {
-                for (;; n++) {
-                        if (additional_error_maps[n] == NULL)
-                                break;
-
+        if (additional_error_maps)
+                for (; additional_error_maps[n] != NULL; n++)
                         if (additional_error_maps[n] == map)
                                 return 0;
-                }
-        }
 
         maps = realloc_multiply(additional_error_maps, sizeof(struct sd_bus_error_map*), n + 2);
         if (!maps)
                 return -ENOMEM;
 
-
         maps[n] = map;
         maps[n+1] = NULL;