From 4088f2e70ac93d4669ff7b00717a2d4ac27cdd10 Mon Sep 17 00:00:00 2001
From: Bryan Housel <bryan@7thposition.com>
Date: Fri, 5 Dec 2014 11:15:45 -0500
Subject: [PATCH] properly load changed entities into altgraph and produce
 diffs.

---
 js/id/core/graph.js   |  5 +----
 js/id/core/history.js |  4 ++++
 js/id/id.js           |  2 +-
 js/id/modes/save.js   | 41 +++++++++++++++++++++++++++--------------
 4 files changed, 33 insertions(+), 19 deletions(-)

diff --git a/js/id/core/graph.js b/js/id/core/graph.js
index 7d0f1452a..8a514b21e 100644
--- a/js/id/core/graph.js
+++ b/js/id/core/graph.js
@@ -16,10 +16,7 @@ iD.Graph = function(other, mutable) {
 
     this.transients = {};
     this._childNodes = {};
-
-    if (!mutable) {
-        this.freeze();
-    }
+    this.frozen = !mutable;
 };
 
 iD.Graph.prototype = {
diff --git a/js/id/core/history.js b/js/id/core/history.js
index e6d948b90..b7b80fa6a 100644
--- a/js/id/core/history.js
+++ b/js/id/core/history.js
@@ -41,6 +41,10 @@ iD.History = function(context) {
             return stack[index].graph;
         },
 
+        base: function() {
+            return stack[0].graph;
+        },
+
         merge: function(entities, extent) {
             stack[0].graph.rebase(entities, _.pluck(stack, 'graph'), false);
             tree.rebase(entities, false);
diff --git a/js/id/id.js b/js/id/id.js
index b1147c2bb..2bea474aa 100644
--- a/js/id/id.js
+++ b/js/id/id.js
@@ -56,7 +56,7 @@ window.iD = function () {
 
     connection.on('load.context', function loadContext(err, result) {
         if (altGraph) {
-            altGraph.rebase(result.data, [altGraph], false);
+            _.each(result.data, function(entity) { altGraph.replace(entity); });
         } else {
             history.merge(result.data, result.extent);
         }
diff --git a/js/id/modes/save.js b/js/id/modes/save.js
index 44be0656a..3ab835a14 100644
--- a/js/id/modes/save.js
+++ b/js/id/modes/save.js
@@ -8,12 +8,13 @@ iD.modes.Save = function(context) {
     }
 
     function save(e) {
-        var altGraph = iD.Graph(),
+        var altGraph = iD.Graph(context.history().base(), true),
             history = context.history(),
             connection = context.connection(),
             changes = history.changes(iD.actions.DiscardTags(history.difference())),
-            toCheck = _.pluck(changes.modified, 'id'),
             loading = iD.ui.Loading(context).message(t('save.uploading')).blocking(true),
+            toCheck = _.pluck(changes.modified, 'id'),
+            toMerge = [];
             errors = [];
 
         context.container()
@@ -21,32 +22,44 @@ iD.modes.Save = function(context) {
 
         // check for version conflicts.. reload modified entities into an alternate graph.
         context.altGraph(altGraph);
+        _.each(toCheck, check);
 
-        _.each(toCheck, function(id) {
+        function check(id) {
             connection.loadEntity(id, function(err) {
-                var version = context.entity(id).version,
-                    altVersion = context.altGraph().entity(id).version;
-
                 toCheck = _.without(toCheck, id);
 
-                if (version !== altVersion) {
-                    errors.push('Version mismatch for ' + id + ': local=' + version + ', server=' + altVersion);
-                }
-
                 if (err) {
                     errors.push(err.responseText);
                 }
+                else {
+                    var entity = context.graph().entity(id),
+                        altEntity = context.altGraph().entity(id);
+
+                    if (entity.version !== altEntity.version) {
+                        toMerge.push(id);
+                        errors.push('Version mismatch for ' + id + ': local=' + entity.version + ', server=' + altEntity.version);
+                    }
+                }
 
                 if (!toCheck.length) {
                     finalize();
                 }
             });
-        });
+        }
 
+        function merge() {
+            var diff = context.history().difference(),
+                altDiff = iD.Difference(context.history().base(), context.altGraph());
+
+            // TODO
+            debugger;
+        }
 
         function finalize() {
+            if (toMerge.length) merge();
+
             if (errors.length) {
-                showErrors(errors);
+                showErrors();
             } else {
                 connection.putChangeset(
                     changes,
@@ -55,7 +68,7 @@ iD.modes.Save = function(context) {
                     function(err, changeset_id) {
                         if (err) {
                             errors.push(err.responseText);
-                            showErrors(errors);
+                            showErrors();
                         } else {
                             loading.close();
                             context.flush();
@@ -66,7 +79,7 @@ iD.modes.Save = function(context) {
         }
 
 
-        function showErrors(errors) {
+        function showErrors() {
             var confirm = iD.ui.confirm(context.container());
 
             context.altGraph(undefined);