Issue #2976493 by tstoeckler, daffie: Creating a table with an explicitly...

Issue #2976493 by tstoeckler, daffie: Creating a table with an explicitly empty primary key is broken on PostgreSQL

core/lib/Drupal/Core/Database/Driver/pgsql/Schema.php

@@ -249,7 +249,7 @@ protected function createTableSql($name, $table) {
     }
 
     $sql_keys = [];
-    if (isset($table['primary key']) && is_array($table['primary key'])) {
+    if (!empty($table['primary key']) && is_array($table['primary key'])) {
       $sql_keys[] = 'CONSTRAINT ' . $this->ensureIdentifiersLength($name, '', 'pkey') . ' PRIMARY KEY (' . $this->createPrimaryKeySql($table['primary key']) . ')';
     }
     if (isset($table['unique keys']) && is_array($table['unique keys'])) {

core/tests/Drupal/KernelTests/Core/Database/SchemaTest.php

@@ -1009,7 +1009,7 @@ public function testFindPrimaryKeyColumns() {
     $this->assertSame(['id3', 'test_field_2', 'id4'], $method->invoke($schema, 'table_with_pk_3'));
 
     // Test with table without a primary key.
-    $schema->createTable('table_without_pk', [
+    $schema->createTable('table_without_pk_1', [
       'description' => 'Table without primary key.',
       'fields' => [
         'id'  => [
@@ -1022,7 +1022,24 @@ public function testFindPrimaryKeyColumns() {
         ],
       ],
     ]);
-    $this->assertSame([], $method->invoke($schema, 'table_without_pk'));
+    $this->assertSame([], $method->invoke($schema, 'table_without_pk_1'));
+
+    // Test with table with an empty primary key.
+    $schema->createTable('table_without_pk_2', [
+      'description' => 'Table without primary key.',
+      'fields' => [
+        'id'  => [
+          'type' => 'int',
+          'not null' => TRUE,
+        ],
+        'test_field'  => [
+          'type' => 'int',
+          'not null' => TRUE,
+        ],
+      ],
+      'primary key' => [],
+    ]);
+    $this->assertSame([], $method->invoke($schema, 'table_without_pk_2'));
 
     // Test with non existing table.
     $this->assertFalse($method->invoke($schema, 'non_existing_table'));