Deprecate infrequently-used parser-related hooks

The following parser-related hooks have no users in deployed code:
- InternalParseBeforeSanitize
- ParserFetchTemplate
- ParserSectionCreate
- ParserPreSaveTransformComplete
- BeforeParserrenderImageGallery

Code search in WMF-deployed code:
https://codesearch.wmflabs.org/deployed/?q=%5Cb%28InternalParseBeforeSanitize%7CParserFetchTemplate%7CParserSectionCreate%7CParserPreSaveTransformComplete%7CBeforeParserrenderImageGallery%29%5Cb&i=nope&files=&repos=

Code search in all code:
https://codesearch.wmflabs.org/search/?q=%5Cb%28InternalParseBeforeSanitize%7CParserFetchTemplate%7CParserSectionCreate%7CParserPreSaveTransformComplete%7CBeforeParserrenderImageGallery%29%5Cb&i=nope&files=&repos=

Removing as many infrequently-used hooks as possible will aid our
transition from the legacy parser to alternative parsers.

Bug: T236809
Change-Id: I3a09fbe6436232ae0b417ad61b19f8df6d0485e0

RELEASE-NOTES-1.35

@@ -869,6 +869,18 @@ because of Phabricator reports.
   - ::$mRevisionSize
   - ::$mInputSize
   - ::$mInParse
+* The following parser-related hooks have been deprecated:
+  - InternalParseBeforeSanitize
+    * Use an alternative hook which doesn't expose internal half-parsed state,
+      like ParserBeforeInternalParse or ParserAfterTidy
+  - ParserFetchTemplate
+    * Use BeforeParserFetchTemplateAndTitle
+  - ParserSectionCreate
+    * No replacement; <section> tag wrapping will be done by core in future.
+  - ParserPreSaveTransformComplete
+    * No replacement; Content::preSaveTransform() provides for customizable PSTs
+  - BeforeParserrenderImageGallery
+    * No replacement; MediaHandler provides for customizable media rendering
 * The accessor/mutator methods Parser::Options(), Parser::OutputType(), and
   Parser::Title() have been deprecated; use the appropriate Parser::get*
   or Parser::set* methods instead.

docs/hooks.txt

@@ -854,7 +854,8 @@ $title: title of the template
 &$skip: skip this template and link it?
 &$id: the id of the revision being parsed
 
-'BeforeParserrenderImageGallery': Before an image gallery is rendered by Parser.
+'BeforeParserrenderImageGallery': DEPRECATED since 1.35!
+Before an image gallery is rendered by Parser.
 [&]$parser: Parser object
 [&]$ig: ImageGallery object
 
@@ -1900,7 +1901,8 @@ but after nowiki/noinclude/includeonly/onlyinclude and other processings.
 &$text: string containing partially parsed text
 [&]$stripState: Parser's internal StripState object
 
-'InternalParseBeforeSanitize': during Parser's internalParse method just before
+'InternalParseBeforeSanitize': DEPRECATED since 1.35!
+During Parser's internalParse method just before
 the parser removes unwanted/dangerous HTML tags and after nowiki/noinclude/
 includeonly/onlyinclude and other processings. Ideal for syntax-extensions after
 template/parser function execution which respect nowiki and HTML-comments.
@@ -2595,7 +2597,8 @@ $revId: ID of the revision that was parsed to create $parserOutput
 'ParserCloned': Called when the parser is cloned.
 $parser: Newly-cloned Parser object
 
-'ParserFetchTemplate': Called when the parser fetches a template
+'ParserFetchTemplate': DEPRECATED since 1.35!
+Called when the parser fetches a template
 $parser: Parser Parser object or false
 $title: Title object of the template to be fetched
 $rev: Revision object of the template
@@ -2666,13 +2669,15 @@ $parserOutput: The ParserOutput object.
 &$text: The text being transformed, before core transformations are done.
 &$options: The options array being used for the transformation.
 
-'ParserPreSaveTransformComplete': Called from Parser::preSaveTransform() after
+'ParserPreSaveTransformComplete': DEPRECATED since 1.35!
+Called from Parser::preSaveTransform() after
 processing is complete, giving the extension a chance to further modify the
 wikitext.
 $parser: the calling Parser instance
 &$text: The transformed text, which can be modified by the hook
 
-'ParserSectionCreate': Called each time the parser creates a document section
+'ParserSectionCreate': DEPRECATED since 1.35!
+Called each time the parser creates a document section
 from wikitext. Use this to apply per-section modifications to HTML (like
 wrapping the section in a DIV).  Caveat: DIVs are valid wikitext, and a DIV
 can begin in one section and end in another. Make sure your code can handle

includes/parser/Parser.php

@@ -1548,7 +1548,7 @@ class Parser {
 			$text = $this->replaceVariables( $text );
 		}
 
-		Hooks::run( 'InternalParseBeforeSanitize', [ &$parser, &$text, &$this->mStripState ] );
+		Hooks::run( 'InternalParseBeforeSanitize', [ &$parser, &$text, &$this->mStripState ], '1.35' );
 		$text = Sanitizer::removeHTMLtags(
 			$text,
 			// Callback from the Sanitizer for expanding items found in
@@ -3934,7 +3934,7 @@ class Parser {
 				$text = $content ? $content->getWikitextForTransclusion() : null;
 
 				Hooks::run( 'ParserFetchTemplate',
-					[ $parser, $title, $rev, &$text, &$deps ] );
+					[ $parser, $title, $rev, &$text, &$deps ], '1.35' );
 
 				if ( $text === false || $text === null ) {
 					$text = false;
@@ -4715,7 +4715,7 @@ class Parser {
 			 * &$sectionContent : ref to the content of the section
 			 * $maybeShowEditLinks : boolean describing whether this section has an edit link
 			 */
-			Hooks::run( 'ParserSectionCreate', [ $this, $i, &$sections[$i], $maybeShowEditLink ] );
+			Hooks::run( 'ParserSectionCreate', [ $this, $i, &$sections[$i], $maybeShowEditLink ], '1.35' );
 
 			$i++;
 		}
@@ -4769,7 +4769,7 @@ class Parser {
 		$text = $this->mStripState->unstripBoth( $text );
 
 		Hooks::run( 'ParserPreSaveTransformComplete',
-			[ $this, &$text ] );
+			[ $this, &$text ], '1.35' );
 
 		$this->setUser( null ); # Reset
 
@@ -5279,7 +5279,7 @@ class Parser {
 
 		// Avoid PHP 7.1 warning from passing $this by reference
 		$parser = $this;
-		Hooks::run( 'BeforeParserrenderImageGallery', [ &$parser, &$ig ] );
+		Hooks::run( 'BeforeParserrenderImageGallery', [ &$parser, &$ig ], '1.35' );
 
 		$lines = StringUtils::explode( "\n", $text );
 		foreach ( $lines as $line ) {