Restored relevant changes from #2850, PowerKiKi/default-values-with-backslashes

UPGRADE.md

 # Upgrade to 2.10
 
+## MINOR BC BREAK: escaped default values
+
+Default values will be automatically escaped. So default values must now be specified non-escaped.
+
+Before:
+
+    $column->setDefault('Foo\\\\Bar\\\\Baz');
+
+After:
+
+    $column->setDefault('Foo\\Bar\\Baz');
+
 ## Deprecated `Type::*` constants
 
 The constants for built-in types have been moved from `Doctrine\DBAL\Types\Type` to a separate class `Doctrine\DBAL\Types\Types`.

lib/Doctrine/DBAL/Platforms/AbstractPlatform.php

@@ -2311,7 +2311,7 @@ abstract class AbstractPlatform
             return " DEFAULT '" . $this->convertBooleans($default) . "'";
         }
 
-        return " DEFAULT '" . $default . "'";
+        return ' DEFAULT ' . $this->quoteStringLiteral($default);
     }
 
     /**

lib/Doctrine/DBAL/Schema/PostgreSqlSchemaManager.php

@@ -395,11 +395,12 @@ class PostgreSqlSchemaManager extends AbstractSchemaManager
                 $length = null;
                 break;
             case 'text':
+            case '_varchar':
+            case 'varchar':
+                $tableColumn['default'] = $this->parseDefaultExpression($tableColumn['default']);
                 $fixed                  = false;
                 break;
-            case 'varchar':
             case 'interval':
-            case '_varchar':
                 $fixed = false;
                 break;
             case 'char':
@@ -479,4 +480,16 @@ class PostgreSqlSchemaManager extends AbstractSchemaManager
 
         return $defaultValue;
     }
+
+    /**
+     * Parses a default value expression as given by PostgreSQL
+     */
+    private function parseDefaultExpression(?string $default) : ?string
+    {
+        if ($default === null) {
+            return $default;
+        }
+
+        return str_replace("''", "'", $default);
+    }
 }

lib/Doctrine/DBAL/Schema/SqliteSchemaManager.php

@@ -325,8 +325,9 @@ class SqliteSchemaManager extends AbstractSchemaManager
             $default = null;
         }
         if ($default !== null) {
-            // SQLite returns strings wrapped in single quotes, so we need to strip them
-            $default = preg_replace("/^'(.*)'$/", '\1', $default);
+            // SQLite returns strings wrapped in single quotes and escaped, so we need to strip them
+            $default = preg_replace("/^'(.*)'$/s", '\1', $default);
+            $default = str_replace("''", "'", $default);
         }
         $notnull = (bool) $tableColumn['notnull'];
 

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

@@ -1495,6 +1495,67 @@ abstract class SchemaManagerFunctionalTestCase extends DbalFunctionalTestCase
         self::assertEquals($sequence2InitialValue, $actualSequence2->getInitialValue());
     }
 
+    /**
+     * Returns potential escaped literals from all platforms combined.
+     *
+     * @see https://dev.mysql.com/doc/refman/5.7/en/string-literals.html
+     * @see http://www.sqlite.org/lang_expr.html
+     * @see https://www.postgresql.org/docs/9.6/static/sql-syntax-lexical.html#SQL-SYNTAX-STRINGS-ESCAPE
+     *
+     * @return mixed[][]
+     */
+    private function getEscapedLiterals() : iterable
+    {
+        return [
+            ['An ASCII NUL (X\'00\')', "foo\\0bar"],
+            ['Single quote, C-style', "foo\\'bar"],
+            ['Single quote, doubled-style', "foo''bar"],
+            ['Double quote, C-style', 'foo\\"bar'],
+            ['Double quote, double-style', 'foo""bar'],
+            ['Backspace', 'foo\\bbar'],
+            ['New-line', 'foo\\nbar'],
+            ['Carriage return', 'foo\\rbar'],
+            ['Tab', 'foo\\tbar'],
+            ['ASCII 26 (Control+Z)', 'foo\\Zbar'],
+            ['Backslash (\)', 'foo\\\\bar'],
+            ['Percent (%)', 'foo\\%bar'],
+            ['Underscore (_)', 'foo\\_bar'],
+        ];
+    }
+
+    private function createTableForDefaultValues() : void
+    {
+        $table = new Table('string_escaped_default_value');
+        foreach ($this->getEscapedLiterals() as $i => $literal) {
+            $table->addColumn('field' . $i, 'string', ['default' => $literal[1]]);
+        }
+
+        $table->addColumn('def_foo', 'string');
+        $this->schemaManager->dropAndCreateTable($table);
+    }
+
+    public function testEscapedDefaultValueCanBeIntrospected() : void
+    {
+        $this->createTableForDefaultValues();
+
+        $onlineTable = $this->schemaManager->listTableDetails('string_escaped_default_value');
+        foreach ($this->getEscapedLiterals() as $i => $literal) {
+            self::assertSame($literal[1], $onlineTable->getColumn('field' . $i)->getDefault(), 'should be able introspect the value of default for: ' . $literal[0]);
+        }
+    }
+
+    public function testEscapedDefaultValueCanBeInserted() : void
+    {
+        $this->createTableForDefaultValues();
+
+        $this->connection->insert('string_escaped_default_value', ['def_foo' => 'foo']);
+
+        foreach ($this->getEscapedLiterals() as $i => $literal) {
+            $value = $this->connection->fetchColumn('SELECT field' . $i . ' FROM string_escaped_default_value');
+            self::assertSame($literal[1], $value, 'inserted default value should be the configured default value for: ' . $literal[0]);
+        }
+    }
+
     /**
      * @group #3086
      */