Revert "Ajax: Always use script injection in globalEval"

This reverts commit bbdfbb4ee859fe9319b348d88120ddc2c9efbd63.

1 files changed, 20 insertions, 6 deletions

diff --git a/src/core.js b/src/core.js
index 72f4de2a0..d3c08c636 100644
--- a/src/core.js
+++ b/src/core.js
@@ -262,12 +262,26 @@ jQuery.extend( {
 	},
 
 	// Evaluates a script in a global context
-	globalEval: function( code, context ) {
-		context = context || document;
-		var script = context.createElement( "script" );
-
-		script.text = code;
-		context.head.appendChild( script ).parentNode.removeChild( script );
+	globalEval: function( code ) {
+		var script,
+			indirect = eval;
+
+		code = jQuery.trim( code );
+
+		if ( code ) {
+			// If the code includes a valid, prologue position
+			// strict mode pragma, execute code by injecting a
+			// script tag into the document.
+			if ( code.indexOf("use strict") === 1 ) {
+				script = document.createElement("script");
+				script.text = code;
+				document.head.appendChild( script ).parentNode.removeChild( script );
+			} else {
+			// Otherwise, avoid the DOM node creation, insertion
+			// and removal by using an indirect global eval
+				indirect( code );
+			}
+		}
 	},
 
 	// Convert dashed to camelCase; used by the css and data modules