Fix itext cursor trail on initDimensions (#3436)

* add clear context top for set

* fix cursor trail

src/shapes/itext.class.js

@@ -306,6 +306,21 @@
       fabric.util.object.extend(this._getStyleDeclaration(loc.lineIndex, loc.charIndex), styles);
     },
 
+    /**
+     * Initialize text dimensions. Render all text on given context
+     * or on a offscreen canvas to get the text width with measureText.
+     * Updates this.width and this.height with the proper values.
+     * Does not return dimensions.
+     * @param {CanvasRenderingContext2D} [ctx] Context to render on
+     * @private
+     */
+    _initDimensions: function(ctx) {
+      if (!ctx) {
+        this.clearContextTop();
+      }
+      this.callSuper('_initDimensions', ctx);
+    },
+
     /**
      * @private
      * @param {CanvasRenderingContext2D} ctx Context to render on

src/shapes/object.class.js

@@ -773,7 +773,7 @@
      * @type Boolean
      * @default
      */
-    statefullCache:            false,
+    statefullCache:            true,
 
     /**
      * When `true`, cache does not get updated during scaling. The picture will get blocky if scaled
@@ -851,10 +851,10 @@
           dim = this._getNonTransformedDimensions(),
           retina = this.canvas && this.canvas._isRetinaScaling() ? fabric.devicePixelRatio : 1,
           zoomX = objectScale.scaleX * zoom * retina,
-          zoomY = objectScale.scaleY * zoom * retina;
-      if (zoomX !== this.zoomX || zoomY !== this.zoomY) {
-        var width = dim.x * zoomX,
-            height = dim.y * zoomY;
+          zoomY = objectScale.scaleY * zoom * retina,
+          width = dim.x * zoomX,
+          height = dim.y * zoomY;
+      if (width !== this.cacheWidth || height !== this.cacheHeight) {
         this._cacheCanvas.width = width;
         this._cacheCanvas.height = height;
         this._cacheContext.translate(width / 2, height / 2);