From 61591f6a2ed5bc1659dfe913daf787b859e103df Mon Sep 17 00:00:00 2001
From: JFH <jfh@JFH-MacBook-Air.local>
Date: Sun, 28 Jun 2020 21:52:27 +0200
Subject: [PATCH] fix issue with undo because this.elem was overwritten with
 node.remove()

---
 cypress/integration/ui/issues/issue-359.js | 26 ++++++++++++++++++++++
 editor/extensions/ext-connector.js         |  7 +++---
 editor/history.js                          |  4 ++--
 editor/svgcanvas.js                        |  2 +-
 4 files changed, 33 insertions(+), 6 deletions(-)
 create mode 100644 cypress/integration/ui/issues/issue-359.js

diff --git a/cypress/integration/ui/issues/issue-359.js b/cypress/integration/ui/issues/issue-359.js
new file mode 100644
index 00000000..a07749ca
--- /dev/null
+++ b/cypress/integration/ui/issues/issue-359.js
@@ -0,0 +1,26 @@
+import {
+  visitAndApproveStorage
+} from '../../../support/ui-test-helper.js';
+
+// See https://github.com/SVG-Edit/svgedit/issues/359
+describe('Fix issue 359', function () {
+  beforeEach(() => {
+    visitAndApproveStorage();
+  });
+
+  it('can undo without throwing', function () {
+    cy.get('#tool_source').click();
+    cy.get('#svg_source_textarea')
+      .type('{selectall}')
+      .type(`<svg width="640" height="480" xmlns="http://www.w3.org/2000/svg">
+      <g class="layer">
+       <title>Layer 1</title>
+        <rect fill="#ffff00" height="70" width="165" x="179.5" y="146.5"/>
+      </g>
+     </svg>`, {parseSpecialCharSequences: false});
+    cy.get('#tool_source_save').click();
+    cy.get('#tool_undo').click();
+    cy.get('#tool_redo').click(); // test also redo to make the test more comprehensive
+    // if the undo throws an error to the console, the test will fail
+  });
+});
diff --git a/editor/extensions/ext-connector.js b/editor/extensions/ext-connector.js
index 48284e6f..7cd1f70a 100644
--- a/editor/extensions/ext-connector.js
+++ b/editor/extensions/ext-connector.js
@@ -573,18 +573,19 @@ export default {
       },
       elementChanged (opts) {
         let elem = opts.elems[0];
-        if (elem && elem.tagName === 'svg' && elem.id === 'svgcontent') {
+        if (!elem) return;
+        if (elem.tagName === 'svg' && elem.id === 'svgcontent') {
           // Update svgcontent (can change on import)
           svgcontent = elem;
           init();
         }
 
         // Has marker, so change offset
-        if (elem && (
+        if (
           elem.getAttribute('marker-start') ||
           elem.getAttribute('marker-mid') ||
           elem.getAttribute('marker-end')
-        )) {
+        ) {
           const start = elem.getAttribute('marker-start');
           const mid = elem.getAttribute('marker-mid');
           const end = elem.getAttribute('marker-end');
diff --git a/editor/history.js b/editor/history.js
index 40f0064a..00acda69 100644
--- a/editor/history.js
+++ b/editor/history.js
@@ -223,7 +223,7 @@ export class InsertElementCommand extends Command {
     }
 
     this.parent = this.elem.parentNode;
-    this.elem = this.elem.remove();
+    this.elem.remove();
 
     if (handler) {
       handler.handleHistoryEvent(HistoryEventTypes.AFTER_UNAPPLY, this);
@@ -280,7 +280,7 @@ export class RemoveElementCommand extends Command {
 
     removeElementFromListMap(this.elem);
     this.parent = this.elem.parentNode;
-    this.elem = this.elem.remove();
+    this.elem.remove();
 
     if (handler) {
       handler.handleHistoryEvent(HistoryEventTypes.AFTER_APPLY, this);
diff --git a/editor/svgcanvas.js b/editor/svgcanvas.js
index 4c9d7804..8ac7b4af 100644
--- a/editor/svgcanvas.js
+++ b/editor/svgcanvas.js
@@ -516,7 +516,7 @@ const undoMgr = canvas.undoMgr = new UndoManager({
         } else if (!isApply) {
           restoreRefElems(cmd.elem);
         }
-        if (cmd.elem.tagName === 'use') {
+        if (cmd.elem && cmd.elem.tagName === 'use') {
           setUseData(cmd.elem);
         }
       } else if (cmdType === ChangeElementCommand.type()) {