fix(dia.LinkView): fix missing arrowheads in Safari (#2677)

packages/joint-core/src/dia/LinkView.mjs

@@ -5,7 +5,7 @@ import { addClassNamePrefix, merge, assign, isObject, isFunction, clone, isPerce
 import { Point, Line, Path, normalizeAngle, Rect, Polyline } from '../g/index.mjs';
 import * as routers from '../routers/index.mjs';
 import * as connectors from '../connectors/index.mjs';
-
+import { env } from '../env/index.mjs';
 
 const Flags = {
     TOOLS: CellView.Flags.TOOLS,
@@ -99,6 +99,11 @@ export const LinkView = CellView.extend({
             this.updateHighlighters(true);
             this.updateTools(opt);
             flags = this.removeFlag(flags, [Flags.RENDER, Flags.UPDATE, Flags.LABELS, Flags.TOOLS, Flags.CONNECTOR]);
+
+            if (env.test('isSafari')) {
+                this.__fixSafariBug268376();
+            }
+
             return flags;
         }
 
@@ -151,6 +156,19 @@ export const LinkView = CellView.extend({
         return flags;
     },
 
+    __fixSafariBug268376: function() {
+        // Safari has a bug where any change after the first render is not reflected in the DOM.
+        // https://bugs.webkit.org/show_bug.cgi?id=268376
+        const { el } = this;
+        const childNodes = Array.from(el.childNodes);
+        const fragment = document.createDocumentFragment();
+        for (let i = 0, n = childNodes.length; i < n; i++) {
+            el.removeChild(childNodes[i]);
+            fragment.appendChild(childNodes[i]);
+        }
+        el.appendChild(fragment);
+    },
+
     requestConnectionUpdate: function(opt) {
         this.requestUpdate(this.getFlag(Flags.UPDATE), opt);
     },

packages/joint-core/src/env/index.mjs

@@ -7,6 +7,11 @@ export const env = {
         svgforeignobject: function() {
             return !!document.createElementNS &&
                 /SVGForeignObject/.test(({}).toString.call(document.createElementNS('http://www.w3.org/2000/svg', 'foreignObject')));
+        },
+
+        // works for iOS browsers too
+        isSafari: function() {
+            return /Safari/.test(navigator.userAgent) && /Apple Computer/.test(navigator.vendor);
         }
     },