From 0d36e565a954d57fe033f533f2a68e5450b0298a Mon Sep 17 00:00:00 2001
From: Andrea Bogazzi <andreabogazzi79@gmail.com>
Date: Thu, 7 Sep 2017 09:39:00 +0200
Subject: [PATCH] improved docs, fixed dirty on group destroy (#4293)

---
 src/mixins/collection.mixin.js | 6 ++++++
 src/shapes/group.class.js      | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/src/mixins/collection.mixin.js b/src/mixins/collection.mixin.js
index 48fa7319c85..df7752c87c6 100644
--- a/src/mixins/collection.mixin.js
+++ b/src/mixins/collection.mixin.js
@@ -10,6 +10,9 @@ fabric.Collection = {
    * (if `renderOnAddRemove` is not `false`).
    * in case of Group no changes to bounding box are made.
    * Objects should be instances of (or inherit from) fabric.Object
+   * Use of this function is highly discouraged for groups.
+   * you can add a bunch of objects with the add method but then you NEED
+   * to run a addWithUpdate call for the Group class or position/bbox will be wrong.
    * @param {...fabric.Object} object Zero or more fabric instances
    * @return {Self} thisArg
    * @chainable
@@ -28,6 +31,9 @@ fabric.Collection = {
   /**
    * Inserts an object into collection at specified index, then renders canvas (if `renderOnAddRemove` is not `false`)
    * An object should be an instance of (or inherit from) fabric.Object
+   * Use of this function is highly discouraged for groups.
+   * you can add a bunch of objects with the insertAt method but then you NEED
+   * to run a addWithUpdate call for the Group class or position/bbox will be wrong.
    * @param {Object} object Object to insert
    * @param {Number} index Index to insert object at
    * @param {Boolean} nonSplicing When `true`, no splicing (shifting) of objects occurs
diff --git a/src/shapes/group.class.js b/src/shapes/group.class.js
index 29cb2d16243..6408646b40d 100644
--- a/src/shapes/group.class.js
+++ b/src/shapes/group.class.js
@@ -393,6 +393,11 @@
      * @chainable
      */
     destroy: function() {
+      // when group is destroyed objects needs to get a repaint to be eventually
+      // displayed on canvas.
+      this._objects.forEach(function(object) {
+        object.set('dirty', true);
+      });
       return this._restoreObjectsState();
     },