MDL-52060 phpunit: Prevent querying database metadata

lib/dml/moodle_database.php

@@ -577,6 +577,11 @@ protected function print_debug_time() {
     protected function where_clause($table, array $conditions=null) {
         // We accept nulls in conditions
         $conditions = is_null($conditions) ? array() : $conditions;
+
+        if (empty($conditions)) {
+            return array('', array());
+        }
+
         // Some checks performed under debugging only
         if (debugging()) {
             $columns = $this->get_columns($table);
@@ -600,9 +605,6 @@ protected function where_clause($table, array $conditions=null) {
         }
 
         $allowed_types = $this->allowed_param_types();
-        if (empty($conditions)) {
-            return array('', array());
-        }
         $where = array();
         $params = array();
 

lib/dml/tests/dml_test.php

@@ -1432,9 +1432,9 @@ public function test_get_records() {
                 $this->assertSame('ddltablenotexist', $e->errorcode);
             }
         }
-        // And without params.
+
         try {
-            $records = $DB->get_records('xxxx', array());
+            $records = $DB->get_records('xxxx', array('id' => '1'));
             $this->fail('An Exception is missing, expected due to query against non-existing table');
         } catch (moodle_exception $e) {
             $this->assertInstanceOf('dml_exception', $e);
@@ -5347,7 +5347,7 @@ public function test_queries_counter() {
 
         // The get_records() method generates 2 queries the first time is called
         // as it is fetching the table structure.
-        $whatever = $DB->get_records($tablename);
+        $whatever = $DB->get_records($tablename, array('id' => '1'));
         $this->assertEquals($initreads + 3, $DB->perf_get_reads());
         $this->assertEquals($initwrites, $DB->perf_get_writes());