SchemaEditor.quote_value is very fragile.

[loic84]

• Quotes in a default value will break SQLite and MySQL. (​https://github.com/django/django/blob/master/django/db/backends/sqlite3/schema.py#L28)
• Oracle doesn't support bytes and breaks on BinaryField.
• Oracle uses repr to quote six.string_types, which will probably result in an extra u prefix. (​https://github.com/django/django/blob/master/django/db/backends/oracle/schema.py#L24)

The PR for #22424 (​https://github.com/django/django/pull/2634) contains tests failing in various configurations.

[Andrew Godwin <andrew@…>]

In 125b3d440761efca8fa808a4b815384ece847d6a:

Fixed #22649: Beefed up quote_value

[Tim Graham <timograham@…>]

In d8c532036a33feacd1420706e0365cf146b9e4b9:

[1.7.x] Fixed #22649: Beefed up quote_value

Backport of 125b3d4407 from master