From 81f1cace4ca31334fb7c68d2bd9a4ba16061b8b7 Mon Sep 17 00:00:00 2001
From: Daniel Friesen <pub-github@nadir-seen-fire.com>
Date: Thu, 16 Aug 2012 00:37:56 -0700
Subject: [PATCH] Fix broken value="" stripping for HTML5

The default value for value="" on <input> elements is not always an
empty string.

In particular the default value for type="radio" is "on" and by
stripping value="" out of the attributes a "" becomes "on" and our
cleanup code ends up breaking forms.

Change-Id: Ibe5a3be3f45a2f93ef95dbe42729b8f8c94a41cb
---
 includes/Html.php                   | 24 ++++++++++++++-
 tests/phpunit/includes/HtmlTest.php | 46 +++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/includes/Html.php b/includes/Html.php
index 7b79146054..35aa2c01c8 100644
--- a/includes/Html.php
+++ b/includes/Html.php
@@ -323,7 +323,6 @@ class Html {
 			'input' => array(
 				'formaction' => 'GET',
 				'type' => 'text',
-				'value' => '',
 			),
 			'keygen' => array( 'keytype' => 'rsa' ),
 			'link' => array( 'media' => 'all' ),
@@ -364,6 +363,29 @@ class Html {
 		&& strval( $attribs['type'] ) == 'text/css' ) {
 			unset( $attribs['type'] );
 		}
+		if ( $element === 'input' ) {
+			$type = isset( $attribs['type'] ) ? $attribs['type'] : null;
+			$value = isset( $attribs['value'] ) ? $attribs['value'] : null;
+			if ( $type === 'checkbox' || $type === 'radio' ) {
+				// The default value for checkboxes and radio buttons is 'on'
+				// not ''. By stripping value="" we break radio boxes that
+				// actually wants empty values.
+				if ( $value === 'on' ) {
+					unset( $attribs['value'] );
+				}
+			} elseif ( $type === 'submit' ) {
+				// The default value for submit appears to be "Submit" but
+				// let's not bother stripping out localized text that matches
+				// that.
+			} else {
+				// The default value for nearly every other field type is ''
+				// The 'range' and 'color' types use different defaults but
+				// stripping a value="" does not hurt them.
+				if ( $value === '' ) {
+					unset( $attribs['value'] );
+				}
+			}
+		}
 		if ( $element === 'select' && isset( $attribs['size'] ) ) {
 			if ( in_array( 'multiple', $attribs )
 				|| ( isset( $attribs['multiple'] ) && $attribs['multiple'] !== false )
diff --git a/tests/phpunit/includes/HtmlTest.php b/tests/phpunit/includes/HtmlTest.php
index 02a83282ea..a4ddf85cee 100644
--- a/tests/phpunit/includes/HtmlTest.php
+++ b/tests/phpunit/includes/HtmlTest.php
@@ -403,4 +403,50 @@ class HtmlTest extends MediaWikiTestCase {
 		}
 		return $cases;
 	}
+
+	/**
+	 * Test out Html::element drops default value
+	 * @cover Html::dropDefaults
+	 * @dataProvider provideElementsWithAttributesHavingDefaultValues
+	 */
+	function testDropDefaults( $expected, $element, $message = '' ) {
+		$this->enableHTML5();
+		$this->assertEquals( $expected, $element, $message );
+	}
+
+	function provideElementsWithAttributesHavingDefaultValues() {
+		# Use cases in a concise format:
+		# <expected>, <element name>, <array of attributes> [, <message>]
+		# Will be mapped to Html::element()
+		$cases = array();
+		$cases[] = array( '<input type="checkbox" />',
+			'input', array( 'type' => 'checkbox', 'value' => 'on' ),
+			'Default value "on" is stripped of checkboxes',
+		);
+		$cases[] = array( '<input type="radio" />',
+			'input', array( 'type' => 'radio', 'value' => 'on' ),
+			'Default value "on" is stripped of radio buttons',
+		);
+		$cases[] = array( '<input type="submit" value="Submit" />',
+			'input', array( 'type' => 'submit', 'value' => 'Submit' ),
+			'Default value "Submit" is kept on submit buttons (for possible l10n issues)',
+		);
+		$cases[] = array( '<input type="color" />',
+			'input', array( 'type' => 'color', 'value' => '' ),
+		);
+		$cases[] = array( '<input type="range" />',
+			'input', array( 'type' => 'range', 'value' => '' ),
+		);
+
+		# Craft the Html elements
+		$ret = array();
+		foreach( $cases as $case ) {
+			$ret[] = array(
+				$case[0],
+				Html::element( $case[1], $case[2] )
+			);
+		}
+		return $ret;
+	}
+
 }
-- 
2.20.1