Remove use of explodeMarkup

* At that point, element attributes are already escaped so it serves no
   purpose. Before `doTableStuff` is called, `Sanitizer::removeHTMLtags`
   has been invoked which calls `Sanitizer::fixTagAttributes` which
   calls `Sanitizer::safeEncodeTagAttributes` and finally gets down to
   `Sanitizer::safeEncodeAttribute`, with the goal of "extra armoring
   against further wiki processing."

Change-Id: Ieeb9b21148c2909eb839d13195d7d10012b48e3b

includes/parser/Parser.php

@@ -1113,15 +1113,15 @@ class Parser {
 					$line = substr( $line, 1 );
 				}
 
+				// Implies both are valid for table headings.
 				if ( $first_character === '!' ) {
 					$line = str_replace( '!!', '||', $line );
 				}
 
 				# Split up multiple cells on the same line.
 				# FIXME : This can result in improper nesting of tags processed
-				# by earlier parser steps, but should avoid splitting up eg
-				# attribute values containing literal "||".
-				$cells = StringUtils::explodeMarkup( '||', $line );
+				# by earlier parser steps.
+				$cells = explode( '||', $line );
 
 				$outLine = '';
 

tests/parser/parserTests.txt

@@ -6334,6 +6334,24 @@ parsoid=wt2html,html2html
 <td data-parsoid='{"startTagSrc":"| ","attrSepSrc":"|","autoInsertedEnd":true}'><a rel="mw:ExtLink" href="ftp://|x||"></a>" onmouseover="alert(document.cookie)">test</td></tr></tbody></table>
 !! end
 
+!! test
+! and || in element attributes should not be parsed as <th>/<td>
+!! wikitext
+{|
+| <div style="color: red !important;" data-contrived="put this here ||">hi</div>
+|}
+!! html/php
+<table>
+<tr>
+<td> <div style="color: red !important;" data-contrived="put this here &#124;&#124;">hi</div>
+</td></tr></table>
+
+!! html/parsoid
+<table>
+<tbody><tr><td> <div style="color: red !important;" data-contrived="put this here ||" data-parsoid='{"stx":"html"}'>hi</div></td></tr>
+</tbody></table>
+!! end
+
 # FIXME: The output seems broken. Filed as T110268.
 !! test
 ! and || in td attributes should not be parsed as <th>/<td>