From 5e8d48b3314c417cd5244e9698dfeabfc12521bf Mon Sep 17 00:00:00 2001
From: Adam Wight <adam.wight@wikimedia.de>
Date: Thu, 24 Oct 2019 11:23:44 +0200
Subject: [PATCH] Minimal support for bookreferencing tag

Allows the "refines" attribute when the feature flag is set, but doesn't
render.  This is part of our rollback strategy, so that we aren't left
with invalid wikitext in case of undeployment.

Bug: T236257
Change-Id: I936be0e62dccb46caeb84162d2c5166956fd9916
---
 includes/Cite.php                | 14 +++++++++++++
 tests/parser/citeParserTests.txt | 35 ++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/includes/Cite.php b/includes/Cite.php
index d8af7d34d..b12545203 100644
--- a/includes/Cite.php
+++ b/includes/Cite.php
@@ -61,6 +61,12 @@ class Cite {
 	 */
 	private const CACHE_DURATION_ONFETCH = 18000;
 
+	/**
+	 * Wikitext attribute name for Book Referencing.
+	 * TODO: Still under discussion.
+	 */
+	public const REFINES_ATTRIBUTE = 'refines';
+
 	/**
 	 * Datastructure representing <ref> input, in the format of:
 	 * <code>
@@ -391,6 +397,7 @@ class Cite {
 	 *  "group" : Group to which it belongs. Needs to be passed to <references /> too.
 	 *  "follow" : If the current reference is the continuation of another, key of that reference.
 	 *  "dir" : set direction of text (ltr/rtl)
+	 *  "refines": Points to a named reference which serves as the context for this reference.
 	 *
 	 * @param string[] $argv The argument vector
 	 * @return (string|false|null)[] An array with exactly four elements, where each is a string on
@@ -398,6 +405,8 @@ class Cite {
 	 * @return-taint tainted
 	 */
 	private function refArg( array $argv ) {
+		global $wgCiteBookReferencing;
+
 		$group = null;
 		$key = null;
 		$follow = null;
@@ -438,6 +447,11 @@ class Cite {
 			$group = $argv['group'];
 			unset( $argv['group'] );
 		}
+		if ( $wgCiteBookReferencing && isset( $argv[self::REFINES_ATTRIBUTE] ) ) {
+			// TODO: Extract the name and return it.
+			// $refines = trim( $argv[self::REFINES_ATTRIBUTE] );
+			unset( $argv[self::REFINES_ATTRIBUTE] );
+		}
 
 		if ( $argv !== [] ) {
 			// Invalid key
diff --git a/tests/parser/citeParserTests.txt b/tests/parser/citeParserTests.txt
index db689c4fb..d5dd509f9 100644
--- a/tests/parser/citeParserTests.txt
+++ b/tests/parser/citeParserTests.txt
@@ -1709,3 +1709,38 @@ wgFragmentMode=['legacy']
 <p><sup about="#mwt2" class="mw-ref" id="cite_ref-füllen_1-0" rel="dc:references" typeof="mw:Extension/ref" data-mw='{"name":"ref","attrs":{"name":"füllen"},"body":{"id":"mw-reference-text-cite_note-füllen-1"}}'><a href="./Parser_test#cite_note-füllen_1-1" style="counter-reset: mw-Ref 1;"><span class="mw-reflink-text">[1]</span></a></sup></p>
 <ol class="mw-references references" typeof="mw:Extension/references" about="#mwt3" data-mw='{"name":"references","attrs":{}}'><li about="#cite_note-füllen-1" id="cite_note-füllen-1"><a href="./Parser_test#cite_ref-füllen-0" rel="mw:referencedBy"><span class="mw-linkback-text">↑ </span></a> <span id="mw-reference-text-cite_note-füllen-1" class="mw-reference-text" data-parsoid="{}">[bar]</span></li></ol>
 !! end
+
+!! test
+Refines tag rejected by default
+!! config
+wgCiteBookReferencing=false
+!! wikitext
+<ref name="parent">[foo]</ref>
+<ref refines="parent">[bar]</ref>
+!! html/php
+<p><sup id="cite_ref-parent_1-0" class="reference"><a href="#cite_note-parent-1">&#91;1&#93;</a></sup>
+<span class="error mw-ext-cite-error" lang="en" dir="ltr">Cite error: Invalid <code>&lt;ref&gt;</code> tag;
+</p>
+invalid names, e.g. too many</span><div class="mw-references-wrap"><ol class="references">
+<li id="cite_note-parent-1"><span class="mw-cite-backlink"><a href="#cite_ref-parent_1-0">↑</a></span> <span class="reference-text">[foo]</span>
+</li>
+</ol></div>
+!! end
+
+!! test
+Refines tag allowed with feature flag set
+!! config
+wgCiteBookReferencing=true
+!! wikitext
+<ref name="parent">[foo]</ref>
+<ref refines="parent">[bar]</ref>
+!! html/php
+<p><sup id="cite_ref-parent_1-0" class="reference"><a href="#cite_note-parent-1">&#91;1&#93;</a></sup>
+</p>
+<sup id="cite_ref-2" class="reference"><a href="#cite_note-2">&#91;2&#93;</a></sup><div class="mw-references-wrap"><ol class="references">
+<li id="cite_note-parent-1"><span class="mw-cite-backlink"><a href="#cite_ref-parent_1-0">↑</a></span> <span class="reference-text">[foo]</span>
+</li>
+<li id="cite_note-2"><span class="mw-cite-backlink"><a href="#cite_ref-2">↑</a></span> <span class="reference-text">[bar]</span>
+</li>
+</ol></div>
+!! end