Fix parse error when opacity is set to zero to alpha() function

Bug was as a result of matchReg returning "0" (zero string) when opacity is set to zero. PHP sees this as false and ends up throwing a Less_Exception_Parser. Bug: T371606 Change-Id: I75704789eac249e48336898730a573ed1cddafef
wikimedia · Aug 6, 2024 · 0d80730 · 0d80730
1 parent c28be8d
commit 0d80730
Show file tree

Hide file tree

Showing 3 changed files with 7 additions and 1 deletion.
diff --git a/lib/Less/Parser.php b/lib/Less/Parser.php
@@ -2134,7 +2134,7 @@ private function parseAlpha() {
 		}
 
 		$value = $this->matchReg( '/\\G[0-9]+/' );
-		if ( !$value ) {
+		if ( $value === null ) {
 			$value = $this->expect( 'parseEntitiesVariable', 'Could not parse alpha' );
 		}
 

diff --git a/test/Fixtures/less.php/css/T371606-alpha-zero-error.css b/test/Fixtures/less.php/css/T371606-alpha-zero-error.css
@@ -0,0 +1,3 @@
+.alpha {
+  filter: alpha(opacity=0);
+}
diff --git a/test/Fixtures/less.php/less/T371606-alpha-zero-error.less b/test/Fixtures/less.php/less/T371606-alpha-zero-error.less
@@ -0,0 +1,3 @@
+.alpha {
+	filter: alpha(opacity=0);
+  }