Support for IE hack parsing in lenient mode

lib/Sabberworm/CSS/Parser.php

@@ -255,6 +255,10 @@ private function parseStringValue() {
 
 	private function parseCharacter($bIsForIdentifier) {
 		if ($this->peek() === '\\') {
+			if ($bIsForIdentifier && $this->oParserSettings->bLenientParsing && ($this->comes('\0') || $this->comes('\9'))) {
+				// Non-strings can contain \0 or \9 which is an IE hack supported in lenient parsing.
+				return null;
+			}
 			$this->consume('\\');
 			if ($this->comes('\n') || $this->comes('\r')) {
 				return '';
@@ -350,6 +354,13 @@ private function parseRule() {
 		$this->consume(':');
 		$oValue = $this->parseValue(self::listDelimiterForRule($oRule->getRule()));
 		$oRule->setValue($oValue);
+		if ($this->oParserSettings->bLenientParsing) {
+			while ($this->comes('\\')) {
+				$this->consume('\\');
+				$oRule->addIeHack($this->consume());
+				$this->consumeWhiteSpace();
+			}
+		}
 		if ($this->comes('!')) {
 			$this->consume('!');
 			$this->consumeWhiteSpace();
@@ -367,7 +378,7 @@ private function parseValue($aListDelimiters) {
 		$aStack = array();
 		$this->consumeWhiteSpace();
 		//Build a list of delimiters and parsed values
-		while (!($this->comes('}') || $this->comes(';') || $this->comes('!') || $this->comes(')'))) {
+		while (!($this->comes('}') || $this->comes(';') || $this->comes('!') || $this->comes(')') || $this->comes('\\'))) {
 			if (count($aStack) > 0) {
 				$bFoundDelimiter = false;
 				foreach ($aListDelimiters as $sDelimiter) {

lib/Sabberworm/CSS/Rule/Rule.php

@@ -15,12 +15,14 @@ class Rule implements Renderable {
 	private $sRule;
 	private $mValue;
 	private $bIsImportant;
+	private $aIeHack;
 	protected $iLineNo;
 
 	public function __construct($sRule, $iLineNo = 0) {
 		$this->sRule = $sRule;
 		$this->mValue = null;
 		$this->bIsImportant = false;
+		$this->aIeHack = array();
 		$this->iLineNo = $iLineNo;
 	}
 
@@ -127,6 +129,18 @@ public function addValue($mValue, $sType = ' ') {
 		}
 	}
 
+	public function addIeHack($iModifier) {
+		$this->aIeHack[] = $iModifier;
+	}
+
+	public function setIeHack(array $aModifiers) {
+		$this->aIeHack = $aModifiers;
+	}
+
+	public function getIeHack() {
+		return $this->aIeHack;
+	}
+
 	public function setIsImportant($bIsImportant) {
 		$this->bIsImportant = $bIsImportant;
 	}
@@ -146,6 +160,9 @@ public function render(\Sabberworm\CSS\OutputFormat $oOutputFormat) {
 		} else {
 			$sResult .= $this->mValue;
 		}
+		if (!empty($this->aIeHack)) {
+			$sResult .= ' \\' . implode('\\', $this->aIeHack);
+		}
 		if ($this->bIsImportant) {
 			$sResult .= ' !important';
 		}

tests/Sabberworm/CSS/ParserTest.php

@@ -505,4 +505,18 @@ function testUnexpectedTokenExceptionLineNo() {
 			throw $e;
 		}
 	}
+
+	/**
+	* @expectedException Sabberworm\CSS\Parsing\UnexpectedTokenException
+	*/
+	function testIeHacksStrictParsing() {
+		// We can't strictly parse IE hacks.
+		$this->parsedStructureForFile('ie-hacks', Settings::create()->beStrict());
+	}
+
+	function testIeHacksParsing() {
+		$oDoc = $this->parsedStructureForFile('ie-hacks', Settings::create()->withLenientParsing(true));
+		$sExpected = 'p {padding-right: .75rem \9;background-image: none \9;color: red \9\0;background-color: red \9\0;background-color: red \9\0 !important;content: "red 	\0";content: "red઼";}';
+		$this->assertEquals($sExpected, $oDoc->render());
+	}
 }

tests/files/ie-hacks.css

@@ -0,0 +1,9 @@
+p {
+    padding-right: .75rem \9;
+    background-image: none \9;
+    color:red\9\0;
+    background-color:red \9 \0;
+    background-color:red \9 \0 !important;
+    content: "red \9\0";
+    content: "red\0abc";
+}