From 3e87c8f9d556351bd0e6ead91078ded4e485ced3 Mon Sep 17 00:00:00 2001
From: David Greenspan <dgreenspan@alum.mit.edu>
Date: Fri, 27 Sep 2013 17:53:06 -0700
Subject: [PATCH] finish optimistic retry code detect collision

---
 packages/mongo-livedata/mongo_driver.js       | 16 +++++++++---
 .../mongo-livedata/mongo_livedata_tests.js    | 26 +++++++++++++++++++
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/packages/mongo-livedata/mongo_driver.js b/packages/mongo-livedata/mongo_driver.js
index e680b1cd79..f0a5bcc8df 100644
--- a/packages/mongo-livedata/mongo_driver.js
+++ b/packages/mongo-livedata/mongo_driver.js
@@ -373,6 +373,13 @@ var numberAffectedCallback = function (callback) {
 
 var NUM_OPTIMISTIC_TRIES = 3;
 
+// exposed for testing
+MongoConnection._isCannotChangeIdError = function (err) {
+  // either of these checks should work, but just to be safe...
+  return (err.code === 13596 ||
+          err.err.indexOf("cannot change _id of a document") === 0);
+};
+
 var simulateUpsertWithInsertedId = function (collection, selector, mod,
                                              isModify, options, callback) {
   var insertedId = options.insertedId; // must exist
@@ -445,11 +452,14 @@ var simulateUpsertWithInsertedId = function (collection, selector, mod,
     collection.update(selector, replacementWithId, mongoOptsForInsert,
                       numberAffectedCallback(function (err, result) {
                         if (err) {
-                          // XXX figure out if this is a
+                          // figure out if this is a
                           // "cannot change _id of document" error, and
                           // if so, try doUpdate() again, up to 3 times.
-                          Meteor._debug(err);
-                          callback(err);
+                          if (MongoConnection._isCannotChangeIdError(err)) {
+                            doUpdate();
+                          } else {
+                            callback(err);
+                          }
                         } else {
                           callback(null, _.extend(result, { insertedId: insertedId }));
                         }
diff --git a/packages/mongo-livedata/mongo_livedata_tests.js b/packages/mongo-livedata/mongo_livedata_tests.js
index e473b1cc0c..0f9f5da7d9 100644
--- a/packages/mongo-livedata/mongo_livedata_tests.js
+++ b/packages/mongo-livedata/mongo_livedata_tests.js
@@ -913,6 +913,32 @@ if (Meteor.isServer) {
     onComplete();
   });
 
+  Tinytest.addAsync("mongo-livedata - upsert error parse, " + idGeneration, function (test, onComplete) {
+    var run = test.runId();
+    var coll = new Meteor.Collection("livedata_upsert_errorparse_collection_"+run, collectionOptions);
+
+    coll.insert({_id: 'foobar'});
+    var err;
+    try {
+      coll.update({_id: 'foobar'}, {_id: 'cowbar'});
+    } catch (e) {
+      err = e;
+    }
+    test.isTrue(err);
+    test.isTrue(MongoInternals.Connection._isCannotChangeIdError(err));
+
+    try {
+      coll.insert({_id: 'foobar'});
+    } catch (e) {
+      err = e;
+    }
+    test.isTrue(err);
+    // duplicate id error is not same as change id error
+    test.isFalse(MongoInternals.Connection._isCannotChangeIdError(err));
+
+    onComplete();
+  });
+
 } // end Meteor.isServer
 
 _.each(Meteor.isServer ? [true, false] : [true], function (minimongo) {