CDRIVER-3773 Remove support for canonical regular expressions with no options (#754)

Author: benjirewis

src/libbson/src/bson/bson-json.c

@@ -1393,6 +1393,10 @@ _bson_json_read_append_regex (bson_json_reader_t *reader,    /* IN */
       _bson_json_read_set_error (
          reader, "Missing \"pattern\" after \"options\" in regular expression");
       return;
+   } else if (!data->regex.has_options) {
+      _bson_json_read_set_error (
+         reader, "Missing \"options\" after \"pattern\" in regular expression");
+      return;
    }
 
    if (!bson_append_regex (STACK_BSON_CHILD,

src/libbson/tests/test-json.c

@@ -1090,24 +1090,6 @@ test_bson_json_read_legacy_regex (void)
                           "Missing \"$regex\" after \"$options\"");
 }
 
-static void
-test_bson_json_read_regex_no_options (void)
-{
-   bson_t b;
-   bson_error_t error;
-   bool r;
-   const char *pattern;
-   const char *flags;
-
-   r = bson_init_from_json (
-      &b, "{\"a\": {\"$regularExpression\": { \"pattern\": \"abc\"}}}", -1, &error);
-   ASSERT_OR_PRINT (r, error);
-   BCON_EXTRACT (&b, "a", BCONE_REGEX (pattern, flags));
-   ASSERT_CMPSTR (pattern, "abc");
-   ASSERT_CMPSTR (flags, "");
-
-   bson_destroy (&b);
-}
 
 static void
 test_bson_json_read_regex_options_order (void)
@@ -3468,8 +3450,6 @@ test_json_install (TestSuite *suite)
       suite, "/bson/json/read/dbpointer", test_bson_json_read_dbpointer);
    TestSuite_Add (
       suite, "/bson/json/read/legacy_regex", test_bson_json_read_legacy_regex);
-   TestSuite_Add (
-      suite, "/bson/json/read/regex_no_options", test_bson_json_read_regex_no_options);
    TestSuite_Add (suite,
                   "/bson/json/read/regex_options_order",
                   test_bson_json_read_regex_options_order);