Index: wp-testcase/test_includes_formatting.php
===================================================================
--- wp-testcase/test_includes_formatting.php	(revision 480)
+++ wp-testcase/test_includes_formatting.php	(working copy)
@@ -452,6 +452,26 @@
 		$this->assertEquals('14×24', wptexturize("14x24"));
 	}
 
+	// WP Ticket #19308
+	// Hex numbers of 0x1234 format should not be texturized as a "x [times] y" equation
+	function test_hex_numbers() {
+		$this->knownWPBug(19308);
+
+		// Hex numbers - these should display without a mathematical multiplaction sign
+		$this->assertEquals('0x70', wptexturize('0x70'));
+		$this->assertEquals('-0x70', wptexturize('-0x70'));
+		$this->assertEquals('0xABCDEF00', wptexturize('0xABCDEF00'));
+		$this->assertEquals('-0xABCDEF00', wptexturize('-0xABCDEF00'));
+		$this->assertEquals('0x3366ff', wptexturize('0x3366ff'));
+		
+		// Nonsense pattern, shouldn't be touched
+		$this->assertEquals('0x1x2x3', wptexturize('0x1x2x3'));
+
+		// Simple equations with a comma and negative operands
+		$this->assertEquals('-123×1=-123', wptexturize('-123x1=-123'));
+		$this->assertEquals('0.675×1=0.675', wptexturize('0.675x1=0.675'));
+	}
+	
 	function test_minutes_seconds() {
 		$this->assertEquals('9′', wptexturize('9\''));
 		$this->assertEquals('9″', wptexturize("9\""));