Use \u{00A0} instead of   or  

Directly use the UTF-8 encoding of the 'NO-BREAK SPACE' (U+00A0) instead of
the HTML/XML entities   or   or  .

With the UTF-8 character the generated HTML is shorter and better to read.

Also change the special value for the label in HTMLForm from   to
U+00A0 but also support   for backward compability.

Bug: T154300
Change-Id: I882599ac1120789bb4e524c4394870680caca4f4

includes/CategoryViewer.php

@@ -581,7 +581,7 @@ class CategoryViewer extends ContextSource {
 
 		foreach ( $colContents as $char => $articles ) {
 			# Change space to non-breaking space to keep headers aligned
-			$h3char = $char === ' ' ? ' ' : htmlspecialchars( $char );
+			$h3char = $char === ' ' ? "\u{00A0}" : htmlspecialchars( $char );
 
 			$ret .= '<div class="mw-category-group"><h3>' . $h3char;
 			$ret .= "</h3>\n";

includes/Html.php

@@ -927,7 +927,7 @@ class Html {
 				'label', [
 					'for' => $selectAttribs['id'] ?? null,
 				], $params['label']
-			) . ' ';
+			) . "\u{00A0}";
 		}
 
 		// Wrap options in a <select>

includes/Xml.php

@@ -382,7 +382,7 @@ class Xml {
 		$value = false, $attribs = []
 	) {
 		list( $label, $input ) = self::inputLabelSep( $label, $name, $id, $size, $value, $attribs );
-		return $label . ' ' . $input;
+		return $label . "\u{00A0}" . $input;
 	}
 
 	/**
@@ -420,7 +420,7 @@ class Xml {
 	public static function checkLabel( $label, $name, $id, $checked = false, $attribs = [] ) {
 		global $wgUseMediaWikiUIEverywhere;
 		$chkLabel = self::check( $name, $checked, [ 'id' => $id ] + $attribs ) .
-			' ' .
+			"\u{00A0}" .
 			self::label( $label, $id, $attribs );
 
 		if ( $wgUseMediaWikiUIEverywhere ) {
@@ -446,7 +446,7 @@ class Xml {
 		$checked = false, $attribs = []
 	) {
 		return self::radio( $name, $value, $checked, [ 'id' => $id ] + $attribs ) .
-			' ' .
+			"\u{00A0}" .
 			self::label( $label, $id, $attribs );
 	}
 

includes/actions/HistoryAction.php

@@ -197,8 +197,8 @@ class HistoryAction extends FormlessAction {
 		$content .= Xml::dateMenu(
 			( $year == null ? MWTimestamp::getLocalInstance()->format( 'Y' ) : $year ),
 			$month
-		) . ' ';
-		$content .= $tagSelector ? ( implode( ' ', $tagSelector ) . ' ' ) : '';
+		) . "\u{00A0}";
+		$content .= $tagSelector ? ( implode( "\u{00A0}", $tagSelector ) . "\u{00A0}" ) : '';
 		$content .= $checkDeleted . Html::submitButton(
 			$this->msg( 'historyaction-submit' )->text(),
 			[],

includes/changes/ChangesList.php

@@ -152,7 +152,7 @@ class ChangesList extends ContextSource {
 	 * @param string $nothing To use for empty space
 	 * @return string
 	 */
-	public function recentChangesFlags( $flags, $nothing = ' ' ) {
+	public function recentChangesFlags( $flags, $nothing = "\u{00A0}" ) {
 		$f = '';
 		foreach ( array_keys( $this->getConfig()->get( 'RecentChangesFlags' ) ) as $flag ) {
 			$f .= isset( $flags[$flag] ) && $flags[$flag]

includes/changes/EnhancedChangesList.php

@@ -715,10 +715,10 @@ class EnhancedChangesList extends ChangesList {
 		}
 
 		if ( isset( $data['timestampLink'] ) ) {
-			$line .= ' ' . $data['timestampLink'];
+			$line .= "\u{00A0}" . $data['timestampLink'];
 			unset( $data['timestampLink'] );
 		}
-		$line .= '&#160;</td>';
+		$line .= "\u{00A0}</td>";
 		$line .= Html::openElement( 'td', [
 			'class' => 'mw-changeslist-line-inner',
 			// Used for reliable determination of the affiliated page

includes/diff/DifferenceEngine.php

@@ -312,7 +312,7 @@ class DifferenceEngine extends ContextSource {
 					$rollbackLink = Linker::generateRollback( $this->mNewRev, $this->getContext() );
 					if ( $rollbackLink ) {
 						$out->preventClickjacking();
-						$rollback = '   ' . $rollbackLink;
+						$rollback = "\u{00A0}\u{00A0}\u{00A0}" . $rollbackLink;
 					}
 				}
 
@@ -342,7 +342,7 @@ class DifferenceEngine extends ContextSource {
 					[ 'diff' => 'prev', 'oldid' => $this->mOldid ] + $query
 				);
 			} else {
-				$prevlink = ' ';
+				$prevlink = "\u{00A0}";
 			}
 
 			if ( $this->mOldRev->isMinor() ) {
@@ -395,7 +395,7 @@ class DifferenceEngine extends ContextSource {
 				[ 'diff' => 'next', 'oldid' => $this->mNewid ] + $query
 			);
 		} else {
-			$nextlink = ' ';
+			$nextlink = "\u{00A0}";
 		}
 
 		if ( $this->mNewRev->isMinor() ) {
@@ -586,7 +586,7 @@ class DifferenceEngine extends ContextSource {
 	protected function revisionDeleteLink( $rev ) {
 		$link = Linker::getRevDeleteLink( $this->getUser(), $rev, $rev->getTitle() );
 		if ( $link !== '' ) {
-			$link = '   ' . $link . ' ';
+			$link = "\u{00A0}\u{00A0}\u{00A0}" . $link . ' ';
 		}
 
 		return $link;

includes/diff/TableDiffFormatter.php

@@ -43,9 +43,9 @@ class TableDiffFormatter extends DiffFormatter {
 	 * @return mixed
 	 */
 	public static function escapeWhiteSpace( $msg ) {
-		$msg = preg_replace( '/^ /m', '  ', $msg );
-		$msg = preg_replace( '/ $/m', '  ', $msg );
-		$msg = preg_replace( '/  /', '  ', $msg );
+		$msg = preg_replace( '/^ /m', "\u{00A0} ", $msg );
+		$msg = preg_replace( '/ $/m', " \u{00A0}", $msg );
+		$msg = preg_replace( '/  /', "\u{00A0} ", $msg );
 
 		return $msg;
 	}
@@ -123,7 +123,7 @@ class TableDiffFormatter extends DiffFormatter {
 	 * @return string
 	 */
 	protected function contextLine( $line ) {
-		return $this->wrapLine( ' ', 'diff-context', $line );
+		return $this->wrapLine( "\u{00A0}", 'diff-context', $line );
 	}
 
 	/**
@@ -146,7 +146,7 @@ class TableDiffFormatter extends DiffFormatter {
 	 * @return string
 	 */
 	protected function emptyLine() {
-		return '<td colspan="2">&#160;</td>';
+		return "<td colspan=\"2\">\u{00A0}</td>";
 	}
 
 	/**

includes/diff/WordAccumulator.php

@@ -66,7 +66,7 @@ class WordAccumulator {
 			array_push( $this->lines, $this->line );
 		} else {
 			# make empty lines visible by inserting an NBSP
-			array_push( $this->lines, ' ' );
+			array_push( $this->lines, "\u{00A0}" );
 		}
 		$this->line = '';
 	}

includes/htmlform/HTMLForm.php

@@ -1662,7 +1662,7 @@ class HTMLForm extends ContextSource {
 					$html[] = $retval;
 
 					$labelValue = trim( $value->getLabel() );
-					if ( $labelValue !== ' ' && $labelValue !== '' ) {
+					if ( $labelValue !== "\u{00A0}" && $labelValue !== '' ) {
 						$hasLabel = true;
 					}
 

includes/htmlform/HTMLFormField.php

@@ -397,9 +397,9 @@ abstract class HTMLFormField {
 		if ( isset( $params['label-message'] ) ) {
 			$this->mLabel = $this->getMessage( $params['label-message'] )->parse();
 		} elseif ( isset( $params['label'] ) ) {
-			if ( $params['label'] === ' ' ) {
+			if ( $params['label'] === ' ' || $params['label'] === "\u{00A0}" ) {
 				// Apparently some things set &nbsp directly and in an odd format
-				$this->mLabel = ' ';
+				$this->mLabel = "\u{00A0}";
 			} else {
 				$this->mLabel = htmlspecialchars( $params['label'] );
 			}
@@ -546,7 +546,7 @@ abstract class HTMLFormField {
 		$horizontalLabel = $this->mParams['horizontal-label'] ?? false;
 
 		if ( $horizontalLabel ) {
-			$field = ' ' . $inputHtml . "\n$errors";
+			$field = "\u{00A0}" . $inputHtml . "\n$errors";
 		} else {
 			$field = Html::rawElement(
 				'div',
@@ -630,7 +630,7 @@ abstract class HTMLFormField {
 
 		// the element could specify, that the label doesn't need to be added
 		$label = $this->getLabel();
-		if ( $label && $label !== ' ' ) {
+		if ( $label && $label !== "\u{00A0}" ) {
 			$config['label'] = new OOUI\HtmlSnippet( $label );
 		}
 
@@ -745,7 +745,7 @@ abstract class HTMLFormField {
 		$label = $this->getLabelHtml( $cellAttributes );
 
 		$html = "\n" . $errors .
-			$label . ' ' .
+			$label . "\u{00A0}" .
 			$inputHtml .
 			$helptext;
 
@@ -926,7 +926,13 @@ abstract class HTMLFormField {
 	 * @return string HTML
 	 */
 	public function getLabel() {
-		return is_null( $this->mLabel ) ? '' : $this->mLabel;
+		if ( is_null( $this->mLabel ) ) {
+			return '';
+		}
+		if ( $this->mLabel === ' ' ) {
+			return "\u{00A0}";
+		}
+		return $this->mLabel;
 	}
 
 	public function getLabelHtml( $cellAttributes = [] ) {
@@ -940,7 +946,7 @@ abstract class HTMLFormField {
 
 		$labelValue = trim( $this->getLabel() );
 		$hasLabel = false;
-		if ( $labelValue !== ' ' && $labelValue !== '' ) {
+		if ( $labelValue !== "\u{00A0}" && $labelValue !== '' ) {
 			$hasLabel = true;
 		}
 

includes/htmlform/fields/HTMLButtonField.php

@@ -46,9 +46,9 @@ class HTMLButtonField extends HTMLFormField {
 		if ( isset( $info['buttonlabel-message'] ) ) {
 			$this->buttonLabel = $this->getMessage( $info['buttonlabel-message'] )->parse();
 		} elseif ( isset( $info['buttonlabel'] ) ) {
-			if ( $info['buttonlabel'] === ' ' ) {
+			if ( $info['buttonlabel'] === ' ' || $info['buttonlabel'] === "\u{00A0}" ) {
 				// Apparently some things set &nbsp directly and in an odd format
-				$this->buttonLabel = ' ';
+				$this->buttonLabel = "\u{00A0}";
 			} else {
 				$this->buttonLabel = htmlspecialchars( $info['buttonlabel'] );
 			}

includes/htmlform/fields/HTMLCheckField.php

@@ -27,7 +27,7 @@ class HTMLCheckField extends HTMLFormField {
 		}
 
 		$chkLabel = Xml::check( $this->mName, $value, $attr ) .
-			' ' .
+			"\u{00A0}" .
 			Html::rawElement( 'label', $attrLabel, $this->mLabel );
 
 		if ( $wgUseMediaWikiUIEverywhere || $this->mParent instanceof VFormHTMLForm ) {
@@ -88,7 +88,7 @@ class HTMLCheckField extends HTMLFormField {
 		) {
 			return '';
 		} else {
-			return ' ';
+			return "\u{00A0}";
 		}
 	}
 

includes/htmlform/fields/HTMLCheckMatrix.php

@@ -88,7 +88,7 @@ class HTMLCheckMatrix extends HTMLFormField implements HTMLNestedFilterable {
 		$attribs = $this->getAttributes( [ 'disabled', 'tabindex' ] );
 
 		// Build the column headers
-		$headerContents = Html::rawElement( 'td', [], ' ' );
+		$headerContents = Html::rawElement( 'td', [], "\u{00A0}" );
 		foreach ( $columns as $columnLabel => $columnTag ) {
 			$headerContents .= Html::rawElement( 'td', [], $columnLabel );
 		}

includes/htmlform/fields/HTMLFormFieldCloner.php

@@ -296,7 +296,7 @@ class HTMLFormFieldCloner extends HTMLFormField {
 				$html .= $field->$getFieldHtmlMethod( $v );
 
 				$labelValue = trim( $field->getLabel() );
-				if ( $labelValue != ' ' && $labelValue !== '' ) {
+				if ( $labelValue != "\u{00A0}" && $labelValue !== '' ) {
 					$hasLabel = true;
 				}
 			}

includes/htmlform/fields/HTMLFormFieldWithButton.php

@@ -70,6 +70,6 @@ class HTMLFormFieldWithButton extends HTMLFormField {
 	 * @return String
 	 */
 	public function getElement( $element ) {
-		return $element . ' ' . $this->getInputHTML( '' );
+		return $element . "\u{00A0}" . $this->getInputHTML( '' );
 	}
 }

includes/htmlform/fields/HTMLMultiSelectField.php

@@ -105,7 +105,7 @@ class HTMLMultiSelectField extends HTMLFormField implements HTMLNestedFilterable
 			$elementFunc = [ Html::class, $this->mOptionsLabelsNotFromMessage ? 'rawElement' : 'element' ];
 			$checkbox =
 				Xml::check( "{$this->mName}[]", $checked, $attribs ) .
-				' ' .
+				"\u{00A0}" .
 				call_user_func( $elementFunc,
 					'label',
 					[ 'for' => $attribs['id'] ],

includes/htmlform/fields/HTMLRadioField.php

@@ -92,7 +92,7 @@ class HTMLRadioField extends HTMLFormField {
 					$classes[] = 'mw-ui-radio';
 				}
 				$radio = Xml::radio( $this->mName, $info, $info === $value, $attribs + [ 'id' => $id ] );
-				$radio .= ' ' . call_user_func( $elementFunc, 'label', [ 'for' => $id ], $label );
+				$radio .= "\u{00A0}" . call_user_func( $elementFunc, 'label', [ 'for' => $id ], $label );
 
 				$html .= ' ' . Html::rawElement(
 					'div',

includes/htmlform/fields/HTMLSizeFilterField.php

@@ -27,7 +27,7 @@ class HTMLSizeFilterField extends HTMLIntField {
 			$value >= 0,
 			$attribs
 		);
-		$html .= ' ' . Xml::radioLabel(
+		$html .= "\u{00A0}" . Xml::radioLabel(
 			$this->msg( 'maximum-size' )->text(),
 			$this->mName . '-mode',
 			'max',
@@ -35,8 +35,8 @@ class HTMLSizeFilterField extends HTMLIntField {
 			$value < 0,
 			$attribs
 		);
-		$html .= '&#160;' . parent::getInputHTML( $value ? abs( $value ) : '' );
-		$html .= '&#160;' . $this->msg( 'pagesize' )->parse();
+		$html .= "\u{00A0}" . parent::getInputHTML( $value ? abs( $value ) : '' );
+		$html .= "\u{00A0}" . $this->msg( 'pagesize' )->parse();
 
 		return $html;
 	}

includes/installer/WebInstaller.php

@@ -758,7 +758,7 @@ class WebInstaller extends Installer {
 	 */
 	public function label( $msg, $forId, $contents, $helpData = "" ) {
 		if ( strval( $msg ) == '' ) {
-			$labelText = ' ';
+			$labelText = '\u{00A0}';
 		} else {
 			$labelText = wfMessage( $msg )->escaped();
 		}
@@ -1047,7 +1047,7 @@ class WebInstaller extends Installer {
 
 			$items[$value] =
 				Xml::radio( $params['controlName'], $value, $checked, $itemAttribs ) .
-				' ' .
+				'\u{00A0}' .
 				Xml::tags( 'label', [ 'for' => $id ], $this->parse(
 					isset( $params['itemLabels'] ) ?
 						wfMessage( $params['itemLabels'][$value] )->plain() :

includes/installer/WebInstallerOptions.php

@@ -412,7 +412,7 @@ class WebInstallerOptions extends WebInstallerPage {
 
 		return '<p>' .
 			Html::element( 'img', [ 'src' => $this->getVar( 'wgRightsIcon' ) ] ) .
-			'&#160;&#160;' .
+			'\u{00A0}\u{00A0}' .
 			htmlspecialchars( $this->getVar( 'wgRightsText' ) ) .
 			"</p>\n" .
 			"<p style=\"text-align: center;\">" .

includes/logging/LogEventsList.php

@@ -135,7 +135,7 @@ class LogEventsList extends ContextSource {
 
 		// Tag filter
 		if ( $tagSelector ) {
-			$html .= Xml::tags( 'p', null, implode( ' ', $tagSelector ) );
+			$html .= Xml::tags( 'p', null, implode( "\u{00A0}", $tagSelector ) );
 		}
 
 		// Filter links

includes/pager/TablePager.php

@@ -119,7 +119,7 @@ abstract class TablePager extends IndexPager {
 		// Make table header
 		foreach ( $fields as $field => $name ) {
 			if ( strval( $name ) == '' ) {
-				$s .= Html::rawElement( 'th', [], ' ' ) . "\n";
+				$s .= Html::rawElement( 'th', [], "\u{00A0}" ) . "\n";
 			} elseif ( $this->isFieldSortable( $field ) ) {
 				$query = [ 'sort' => $field, 'limit' => $this->mLimit ];
 				$linkType = null;
@@ -192,7 +192,7 @@ abstract class TablePager extends IndexPager {
 			$formatted = strval( $this->formatValue( $field, $value ) );
 
 			if ( $formatted == '' ) {
-				$formatted = ' ';
+				$formatted = "\u{00A0}";
 			}
 
 			$s .= Html::rawElement( 'td', $this->getCellAttrs( $field, $value ), $formatted ) . "\n";

includes/specials/SpecialContributions.php

@@ -556,7 +556,7 @@ class SpecialContributions extends IncludableSpecialPage {
 			$filterSelection = Html::rawElement(
 				'div',
 				[],
-				implode( ' ', $tagFilter )
+				implode( "\u{00A0}", $tagFilter )
 			);
 		} else {
 			$filterSelection = Html::rawElement( 'div', [], '' );
@@ -609,7 +609,7 @@ class SpecialContributions extends IncludableSpecialPage {
 				$this->msg( 'namespace' )->text(),
 				'namespace',
 				''
-			) . ' ' .
+			) . "\u{00A0}" .
 			Html::namespaceSelector(
 				[ 'selected' => $this->opts['namespace'], 'all' => '' ],
 				[
@@ -617,7 +617,7 @@ class SpecialContributions extends IncludableSpecialPage {
 					'id' => 'namespace',
 					'class' => 'namespaceselector',
 				]
-			) . ' ' .
+			) . "\u{00A0}" .
 				Html::rawElement(
 					'span',
 					[ 'class' => 'mw-input-with-label' ],
@@ -630,7 +630,7 @@ class SpecialContributions extends IncludableSpecialPage {
 							'title' => $this->msg( 'tooltip-invert' )->text(),
 							'class' => 'mw-input'
 						]
-					) . ' '
+					) . "\u{00A0}"
 				) .
 				Html::rawElement( 'span', [ 'class' => 'mw-input-with-label' ],
 					Xml::checkLabel(
@@ -642,7 +642,7 @@ class SpecialContributions extends IncludableSpecialPage {
 							'title' => $this->msg( 'tooltip-namespace_association' )->text(),
 							'class' => 'mw-input'
 						]
-					) . ' '
+					) . "\u{00A0}"
 				)
 		);
 

includes/specials/SpecialEmailuser.php

@@ -332,7 +332,7 @@ class SpecialEmailUser extends UnlistedSpecialPage {
 			Html::label(
 				$this->msg( 'emailusername' )->text(),
 				'emailusertarget'
-			) . ' ' .
+			) . "\u{00A0}" .
 			Html::input(
 				'target',
 				$name,

includes/specials/SpecialMergeHistory.php

@@ -224,11 +224,11 @@ class SpecialMergeHistory extends SpecialPage {
 					'</td>
 					<td class="mw-input">' .
 					Xml::input( 'wpComment', 50, $this->mComment, [ 'id' => 'wpComment' ] ) .
-					'</td>
+					"</td>
 					</tr>
 					<tr>
-						<td>&#160;</td>
-						<td class="mw-submit">' .
+						<td>\u{00A0}</td>
+						<td class=\"mw-submit\">" .
 					Xml::submitButton(
 						$this->msg( 'mergehistory-submit' )->text(),
 						[ 'name' => 'merge', 'id' => 'mw-merge-submit' ]

includes/specials/SpecialWatchlist.php

@@ -526,7 +526,7 @@ class SpecialWatchlist extends ChangesListSpecialPage {
 								$this->msg( 'watchlist-unwatch' )->text(), [
 									'class' => 'mw-unwatch-link',
 									'title' => $this->msg( 'tooltip-ca-unwatch' )->text()
-								], [ 'action' => 'unwatch' ] ) . ' ';
+								], [ 'action' => 'unwatch' ] ) . "\u{00A0}";
 				}
 			} );
 		}

includes/specials/SpecialWhatlinkshere.php

@@ -523,7 +523,7 @@ class SpecialWhatLinksHere extends IncludableSpecialPage {
 			]
 		);
 
-		$f .= ' ' .
+		$f .= "\u{00A0}" .
 			Xml::checkLabel(
 				$this->msg( 'invert' )->text(),
 				'invert',

includes/specials/pagers/AllMessagesTablePager.php

@@ -357,7 +357,7 @@ class AllMessagesTablePager extends TablePager {
 			$formatted = strval( $this->formatValue( 'am_actual', $row->am_actual ) );
 
 			if ( $formatted === '' ) {
-				$formatted = ' ';
+				$formatted = "\u{00A0}";
 			}
 
 			$s .= Xml::tags( 'td', $this->getCellAttrs( 'am_actual', $row->am_actual ), $formatted )

tests/phpunit/includes/HtmlTest.php

@@ -331,7 +331,7 @@ class HtmlTest extends MediaWikiTestCase {
 		);
 
 		$this->assertEquals(
-			'<label for="mw-test-namespace">Select a namespace:</label>&#160;' .
+			'<label for="mw-test-namespace">Select a namespace:</label>' . "\u{00A0}" .
 				'<select id="mw-test-namespace" name="wpNamespace">' . "\n" .
 				'<option value="all">all</option>' . "\n" .
 				'<option value="0">(Main)</option>' . "\n" .
@@ -359,7 +359,7 @@ class HtmlTest extends MediaWikiTestCase {
 		);
 
 		$this->assertEquals(
-			'<label for="namespace">Select a namespace:</label>&#160;' .
+			'<label for="namespace">Select a namespace:</label>' . "\u{00A0}" .
 				'<select id="namespace" name="namespace">' . "\n" .
 				'<option value="0">(Main)</option>' . "\n" .
 				'<option value="1">Talk</option>' . "\n" .

tests/phpunit/includes/api/ApiOptionsTest.php

@@ -66,7 +66,7 @@ class ApiOptionsTest extends MediaWikiLangTestCase {
 			$preferences[$k] = [
 				'type' => 'text',
 				'section' => 'test',
-				'label' => ' ',
+				'label' => "\u{00A0}",
 			];
 		}
 
@@ -81,7 +81,7 @@ class ApiOptionsTest extends MediaWikiLangTestCase {
 				],
 			],
 			'section' => 'test',
-			'label' => ' ',
+			'label' => "\u{00A0}",
 			'prefix' => 'testmultiselect-',
 			'default' => [],
 		];