when touch overflow scrolling is supported and enabled, user scaling …

…can create serious usability issues where it's difficult to get zoomed back out. This disables user scaling when that overflow scrolling is enabled (currently only projected for ios5 support)

js/jquery.mobile.fixHeaderFooter.native.js

@@ -7,8 +7,12 @@
 
 (function( $, undefined ) {
 
+// Enable touch overflow scrolling when it's natively supported
 $.mobile.touchOverflowEnabled = true;
 
+// Enabled zoom when touch overflow is enabled. Can cause usability issues, unfortunately
+$.mobile.touchOverflowZoomEnabled = false;
+
 $( document ).bind( "pagecreate", function( event ) {
 	if( $.support.touchOverflow && $.mobile.touchOverflowEnabled ){
 

js/jquery.mobile.init.js

@@ -103,6 +103,24 @@
 			}
 		}
 	});
+
+	// This function injects a meta viewport tag to prevent scaling. Off by default, on by default when touchOverflow scrolling is enabled
+	function disableZoom() {
+		var cont = "user-scalable=no",
+			meta = $( "meta[name='viewport']" );
+
+		if( meta.length ){
+			meta.attr( "content", meta.attr( "content" ) + ", " + cont );
+		}
+		else{
+			$( "head" ).prepend( "<meta>", { "name": "viewport", "content": cont } );
+		}
+	}
+
+	// if touch-overflow is enabled, disable user scaling, as it creates usability issues
+	if( $.support.touchOverflow && $.mobile.touchOverflowEnabled && !$.mobile.touchOverflowZoomEnabled ){
+		disableZoom();
+	}
 
 	// initialize events now, after mobileinit has occurred
 	$.mobile._registerInternalEvents();