fixed a couple bugs, local storage perist menu item

index.html

@@ -64,7 +64,9 @@ if (window.location.host.endsWith('8bitworkshop.com')) {
           <hr>
           <li><a class="dropdown-item" href="#" id="item_addfile_include">Add Include File...</a></li>
           <li><a class="dropdown-item" href="#" id="item_addfile_link">Add Linked File...</a></li>
+          <hr>
           <li><a class="dropdown-item" href="#" id="item_switch_https" style="display:none">Switch to HTTPS...</a></li>
+          <li><a class="dropdown-item" href="#" id="item_request_persist">Request Local Storage Permissions</a></li>
         </ul>
       </li>
       <li class="dropdown dropdown-submenu">

src/audio.ts

@@ -396,7 +396,7 @@ export var SampleAudio = function(clockfreq) {
       console.log("no web audio context");
       return;
     }
-    var ctx = new AudioContext();
+    var ctx : AudioContext = new AudioContext();
     self.context = ctx;
     self.sr=self.context.sampleRate;
     self.bufferlen=2048;
@@ -451,7 +451,7 @@ export var SampleAudio = function(clockfreq) {
   }
   
   this.stop = function() {
-    this.context && this.context.suspend();
+    this.context && this.context.suspend && this.context.suspend();
     clearBuffers(); // just in case it doesn't stop immediately
   }
 

src/ui.ts

@@ -1,4 +1,3 @@
-"use strict";
 
 // 8bitworkshop IDE user interface
 
@@ -114,6 +113,19 @@ var hasLocalStorage : boolean = function() {
   }
 }();
 
+// https://developers.google.com/web/updates/2016/06/persistent-storage
+function requestPersistPermission() {
+  if (navigator.storage && navigator.storage.persist) {
+    navigator.storage.persist().then(persistent=>{
+      if (persistent) {
+        alertInfo("We asked your browser to persist local data, and it said yes.");
+      } else {
+        alertInfo("This browser may not persist local data. Are you in a private window?");
+      }
+    });
+  }
+}
+
 function getCurrentPresetTitle() : string {
   if (!current_preset)
     return current_project.mainPath || "ROM";
@@ -1518,6 +1530,7 @@ function setupDebugControls() {
   }
   $("#item_addfile_include").click(_addIncludeFile);
   $("#item_addfile_link").click(_addLinkFile);
+  $("#item_request_persist").click(requestPersistPermission);
   updateDebugWindows();
   // show help button?
   if (platform.showHelp) {

src/views.ts

@@ -569,8 +569,10 @@ export class MemoryView implements ProjectView {
   }
 
   scrollToAddress(addr : number) {
+    if (this.dumplines) {
       this.memorylist.scrollToItem(this.findMemoryWindowLine(addr));
     }
+  }
 
   refresh() {
     this.dumplines = null;