Core: Throw an error on $("#") rather than returning 0-length collection

dmethvin · dmethvin · commit 93f95c966355 · 2014-12-03T14:55:33.000-05:00
Closes gh-1682 Thanks @goob for the issue report! (cherry picked from commit 80022c8)
diff --git a/src/core/init.js b/src/core/init.js
@@ -14,7 +14,8 @@ var rootjQuery,
 	// A simple way to check for HTML strings
 	// Prioritize #id over <tag> to avoid XSS via location.hash (#9521)
 	// Strict HTML recognition (#11290: must start with <)
-	rquickExpr = /^(?:\s*(<[\w\W]+>)[^>]*|#([\w-]*))$/,
+	// Shortcut simple #id case for speed
+	rquickExpr = /^(?:\s*(<[\w\W]+>)[^>]*|#([\w-]+))$/,
 
 	init = jQuery.fn.init = function( selector, context ) {
 		var match, elem;
diff --git a/test/unit/core.js b/test/unit/core.js
@@ -57,10 +57,15 @@ test("jQuery()", function() {
 	equal( jQuery(undefined).length, 0, "jQuery(undefined) === jQuery([])" );
 	equal( jQuery(null).length, 0, "jQuery(null) === jQuery([])" );
 	equal( jQuery("").length, 0, "jQuery('') === jQuery([])" );
-	equal( jQuery("#").length, 0, "jQuery('#') === jQuery([])" );
-
 	equal( jQuery(obj).selector, "div", "jQuery(jQueryObj) == jQueryObj" );
 
+	// Invalid #id goes to Sizzle which will throw an error (gh-1682)
+	try {
+		jQuery( "#" );
+	} catch ( e ) {
+		ok( true, "Threw an error on #id with no id" );
+	}
+
 	// can actually yield more than one, when iframes are included, the window is an array as well
 	equal( jQuery(window).length, 1, "Correct number of elements generated for jQuery(window)" );
 
