Core: use different ready code when Deferred is excluded

Fixes jquerygh-1778

Gruntfile.js

@@ -75,6 +75,7 @@ module.exports = function( grunt ) {
 					callbacks: [ "deferred" ],
 					css: [ "effects", "dimensions", "offset" ],
 					"css/showHide": [ "effects" ],
+					deferred: [ "ajax", "effects" ],
 					sizzle: [ "css/hiddenVisibleSelectors", "effects/animatedSelector" ]
 				}
 			}

src/core/ready-no-deferred.js

@@ -0,0 +1,116 @@
+define( [
+	"../core",
+	"../var/document"
+], function( jQuery, document ) {
+
+var readyCallbacks = [],
+	readyFiring = false,
+	whenReady = function( fn ) {
+		readyCallbacks.push( fn );
+	};
+
+jQuery.fn.ready = function( fn ) {
+	whenReady( fn );
+	return this;
+};
+
+jQuery.extend( {
+
+	// Is the DOM ready to be used? Set to true once it occurs.
+	isReady: false,
+
+	// A counter to track how many items to wait for before
+	// the ready event fires. See #6781
+	readyWait: 1,
+
+	// Hold (or release) the ready event
+	holdReady: function( hold ) {
+		if ( hold ) {
+			jQuery.readyWait++;
+		} else {
+			jQuery.ready( true );
+		}
+	},
+
+	ready: function( wait ) {
+
+		// Abort if there are pending holds or we're already ready
+		if ( wait === true ? --jQuery.readyWait : jQuery.isReady ) {
+			return;
+		}
+
+		// Remember that the DOM is ready
+		jQuery.isReady = true;
+
+		// If a normal DOM Ready event fired, decrement, and wait if need be
+		if ( wait !== true && --jQuery.readyWait > 0 ) {
+			return;
+		}
+
+		whenReady = function( fn ) {
+			readyCallbacks.push( fn );
+
+			if ( !readyFiring ) {
+				readyFiring = true;
+
+				// Prevent errors from freezing future callback execution (gh-1823)
+				try {
+					while ( readyCallbacks.length ) {
+						fn = readyCallbacks.shift();
+						if ( jQuery.isFunction( fn ) ) {
+
+							// For backwards compatibility,
+							// invoke synchronously and with document context
+							fn.call( document, jQuery );
+						}
+					}
+				} finally {
+					readyFiring = false;
+
+					// If there was an error in a ready callback,
+					// continue with the rest (gh-1823)
+					if ( readyCallbacks.length ) {
+
+						// Retry async to allow the error to propagate to console
+						window.setTimeout( whenReady );
+					}
+				}
+			}
+		};
+
+		whenReady();
+	}
+} );
+
+// Make jQuery.ready Promise consumable (gh-1778)
+jQuery.ready.then = jQuery.fn.ready;
+
+/**
+ * The ready event handler and self cleanup method
+ */
+function completed() {
+	document.removeEventListener( "DOMContentLoaded", completed );
+	window.removeEventListener( "load", completed );
+	jQuery.ready();
+}
+
+// Catch cases where $(document).ready() is called
+// after the browser event has already occurred.
+// Support: IE9-10 only
+// Older IE sometimes signals "interactive" too soon
+if ( document.readyState === "complete" ||
+	( document.readyState !== "loading" && !document.documentElement.doScroll ) ) {
+
+	// Handle it asynchronously to allow scripts the opportunity to delay ready
+	window.setTimeout( jQuery.ready );
+
+} else {
+
+	// Use the handy event callback
+	document.addEventListener( "DOMContentLoaded", completed );
+
+	// A fallback to window.onload, that will always work
+	window.addEventListener( "load", completed );
+}
+
+} );

src/core/ready.js

@@ -1,16 +1,18 @@
 define( [
 	"../core",
-	"../var/document"
+	"../var/document",
+	"../deferred"
 ], function( jQuery, document ) {
 
-var readyCallbacks = [],
-	readyFiring = false,
-	whenReady = function( fn ) {
-		readyCallbacks.push( fn );
-	};
+// The deferred used on DOM ready
+var readyList = jQuery.Deferred(),
+	readyPromise = readyList.promise();
 
 jQuery.fn.ready = function( fn ) {
-	whenReady( fn );
+
+	// Add the callback
+	readyPromise.done( fn );
+
 	return this;
 };
 
@@ -32,6 +34,7 @@ jQuery.extend( {
 		}
 	},
 
+	// Handle when the DOM is ready
 	ready: function( wait ) {
 
 		// Abort if there are pending holds or we're already ready
@@ -47,47 +50,14 @@ jQuery.extend( {
 			return;
 		}
 
-		whenReady = function( fn ) {
-			readyCallbacks.push( fn );
-
-			if ( !readyFiring ) {
-				readyFiring = true;
-
-				// Prevent errors from freezing future callback execution (gh-1823)
-				try {
-					while ( readyCallbacks.length ) {
-						fn = readyCallbacks.shift();
-						if ( jQuery.isFunction( fn ) ) {
-
-							// For backwards compatibility,
-							// invoke synchronously and with document context
-							fn.call( document, jQuery );
-						}
-					}
-				} finally {
-					readyFiring = false;
-
-					// If there was an error in a ready callback,
-					// continue with the rest (gh-1823)
-					if ( readyCallbacks.length ) {
-
-						// Retry async to allow the error to propagate to console
-						window.setTimeout( whenReady );
-					}
-				}
-			}
-		};
-
-		whenReady();
+		// If there are functions bound, to execute
+		readyList.resolveWith( document, [ jQuery ] );
 	}
 } );
 
-// Make jQuery.ready Promise consumable (gh-1778)
-jQuery.ready.then = jQuery.fn.ready;
+jQuery.ready.then = readyPromise.then;
 
-/**
- * The ready event handler and self cleanup method
- */
+// The ready event handler and self cleanup method
 function completed() {
 	document.removeEventListener( "DOMContentLoaded", completed );
 	window.removeEventListener( "load", completed );