Alter table with TEXT DEFAULT '' misbehaves

[patsib]

Changing the default value of a field with type TEXT to nothing (empty string), adds two quotes as a new default.

Given a table 'test' with a field 'content' as TEXT.

Reproduce v1:

• open table structure view
• click on CHANGE for field 'content'
• change field settings to DEFAULT 'As defined' and leave default value blank.

Reproduce v2:

• go to SQL and
• ALTER TABLE `test` CHANGE `content` `content` TEXT NOT NULL DEFAULT '';

Expected:

• In the structure view, the default value should be empty and not show '' (compare to type varchar).
• INSERT form should not add '' to the text field but rather leave it empty.

Environment:

• Operating system: Win10
• Web server: Apache/2.4.39 (Win64) OpenSSL/1.1.1c
• Database version: 10.3.15-MariaDB
• PHP version: PHP/7.3.6
• phpMyAdmin version: 4.9.0.1
• Browser: Any
• Operating system: Any

Verified the problem with a completely different linux environment, but i don't have the specs right now.

[patsib]

[nunoperalta]

Just reproduced this and I was going to open an issue!

[williamdes]

Test table:

CREATE TABLE `issue-15363` (
  `id` int(11) DEFAULT NULL,
  `empty text` text DEFAULT '',
  `empty varchar` varchar(25) NOT NULL DEFAULT '',
  `really empty string` varchar(25) NOT NULL DEFAULT '''''',
  `really empty text` text NOT NULL DEFAULT '\'\'',
  `l'eau dans un varchar` varchar(25) NOT NULL DEFAULT 'l''eau ',
  `l'eau 2` text NOT NULL DEFAULT 'l\'eau',
  `l'eau dans un texte` text NOT NULL DEFAULT 'l\'eau',
  `l'eau` varchar(25) NOT NULL DEFAULT 'l''eau \\n \\n \\t l''eau',
  `l'eau 3` text NOT NULL DEFAULT 'l\'eau \\n \\n \\t l\'eau'
) ENGINE=InnoDB;