Improve endpoint for checking if restorable changes exist (re: b4ef0862978ae79a5cb741ac49370ed678857b1f)

modules/core/history.js

@@ -16,6 +16,10 @@ import {
 export function coreHistory(context) {
     var dispatch = d3_dispatch('change', 'merge', 'restore', 'undone', 'redone');
     var lock = utilSessionMutex('lock');
+
+    // restorable if iD not open in another window/tab and a saved history exists in localStorage
+    var _hasUnresolvedRestorableChanges = lock.lock() && !!context.storage(getKey('saved_history'));
+
     var duration = 150;
     var _imageryUsed = [];
     var _photoOverlaysUsed = [];
@@ -635,15 +639,32 @@ export function coreHistory(context) {
         },
 
 
+        lock: function() {
+            return lock.lock();
+        },
+
+
+        unlock: function() {
+            lock.unlock();
+        },
+
+
         save: function() {
-            if (lock.locked()) context.storage(getKey('saved_history'), history.toJSON() || null);
+            if (lock.locked() &&
+                // don't overwrite existing, unresolved changes
+                !_hasUnresolvedRestorableChanges) {
+
+                context.storage(getKey('saved_history'), history.toJSON() || null);
+            }
             return history;
         },
 
 
+        // delete the history version saved in localStorage
         clearSaved: function() {
             context.debouncedSave.cancel();
             if (lock.locked()) {
+                _hasUnresolvedRestorableChanges = false;
                 context.storage(getKey('saved_history'), null);
 
                 // clear the changeset metadata associated with the saved history
@@ -655,29 +676,18 @@ export function coreHistory(context) {
         },
 
 
-        lock: function() {
-            return lock.lock();
-        },
-
-
-        unlock: function() {
-            lock.unlock();
-        },
-
-
-        // is iD not open in another window and it detects that
-        // there's a history stored in localStorage that's recoverable?
-        restorableChanges: function() {
-            return lock.locked() && !!context.storage(getKey('saved_history'));
+        hasRestorableChanges: function() {
+            return _hasUnresolvedRestorableChanges;
         },
 
 
         // load history from a version stored in localStorage
         restore: function() {
-            if (!lock.locked()) return;
-
-            var json = context.storage(getKey('saved_history'));
-            if (json) history.fromJSON(json, true);
+            if (lock.locked()) {
+                _hasUnresolvedRestorableChanges = false;
+                var json = context.storage(getKey('saved_history'));
+                if (json) history.fromJSON(json, true);
+            }
         },
 
 

modules/ui/restore.js

@@ -4,7 +4,7 @@ import { uiModal } from './modal';
 
 export function uiRestore(context) {
   return function(selection) {
-    if (!context.history().lock() || !context.history().restorableChanges()) return;
+    if (!context.history().hasRestorableChanges()) return;
 
     let modalSelection = uiModal(selection, true);
 

modules/ui/splash.js

@@ -8,7 +8,7 @@ export function uiSplash(context) {
     // Exception - if there are restorable changes, skip this splash screen.
     // This is because we currently only support one `uiModal` at a time
     //  and we need to show them `uiRestore`` instead of this one.
-    if (context.history().lock() && context.history().restorableChanges()) return;
+    if (context.history().hasRestorableChanges()) return;
 
     // If user has not seen this version of the privacy policy, show the splash again.
     let updateMessage = '';