fix dropping primary key with autoincrement column in MySQL

lib/Doctrine/DBAL/Platforms/MySqlPlatform.php

@@ -598,6 +598,19 @@ class MySqlPlatform extends AbstractPlatform
         $table = $diff->name;
 
         foreach ($diff->removedIndexes as $remKey => $remIndex) {
+            // Dropping primary keys requires to unset autoincrement attribute on the particular column first.
+            if ($remIndex->isPrimary() && $diff->fromTable instanceof Table) {
+                foreach ($remIndex->getColumns() as $columnName) {
+                    $column = $diff->fromTable->getColumn($columnName);
+
+                    if ($column->getAutoincrement() === true) {
+                        $column->setAutoincrement(false);
+
+                        $sql[] = 'ALTER TABLE ' . $table . ' MODIFY ' .
+                            $this->getColumnDeclarationSQL($column->getQuotedName($this), $column->toArray());
+                    }
+                }
+            }
 
             foreach ($diff->addedIndexes as $addKey => $addIndex) {
                 if ($remIndex->getColumns() == $addIndex->getColumns()) {

tests/Doctrine/Tests/DBAL/Functional/Schema/MySqlSchemaManagerTest.php

@@ -91,4 +91,25 @@ class MySqlSchemaManagerTest extends SchemaManagerFunctionalTestCase
         $this->assertFalse($table->hasIndex('idx_id'));
         $this->assertTrue($table->hasPrimaryKey());
     }
+
+    /**
+     * @group 464
+     */
+    public function testDropPrimaryKeyWithAutoincrementColumn()
+    {
+        $table = new Table("drop_primary_key");
+        $table->addColumn('id', 'integer', array('primary' => true, 'autoincrement' => true));
+        $table->addColumn('foo', 'integer', array('primary' => true));
+        $table->setPrimaryKey(array('id', 'foo'));
+
+        $this->_sm->dropAndCreateTable($table);
+
+        $diffTable = clone $table;
+
+        $diffTable->dropPrimaryKey();
+
+        $comparator = new Comparator();
+
+        $this->_sm->alterTable($comparator->diffTable($table, $diffTable));
+    }
 }

tests/Doctrine/Tests/DBAL/Platforms/MySqlPlatformTest.php

@@ -318,4 +318,29 @@ class MySqlPlatformTest extends AbstractPlatformTestCase
             $this->_platform->getAlterTableSQL($comparator->diffTable($table, $diffTable))
         );
     }
+
+    /**
+     * @group 464
+     */
+    public function testDropPrimaryKeyWithAutoincrementColumn()
+    {
+        $table = new Table("drop_primary_key");
+        $table->addColumn('id', 'integer', array('primary' => true, 'autoincrement' => true));
+        $table->addColumn('foo', 'integer', array('primary' => true));
+        $table->addColumn('bar', 'integer');
+        $table->setPrimaryKey(array('id', 'foo'));
+
+        $comparator = new Comparator();
+        $diffTable = clone $table;
+
+        $diffTable->dropPrimaryKey();
+
+        $this->assertEquals(
+            array(
+                'ALTER TABLE drop_primary_key MODIFY id INT NOT NULL',
+                'ALTER TABLE drop_primary_key DROP PRIMARY KEY'
+            ),
+            $this->_platform->getAlterTableSQL($comparator->diffTable($table, $diffTable))
+        );
+    }
 }