From c499f7c9dae9c3ab19bcfdbcff3dc49ff68469dc Mon Sep 17 00:00:00 2001
From: Avital Oliver <avital@thewe.net>
Date: Mon, 20 Aug 2012 15:07:32 -0700
Subject: [PATCH] Fixes #126 -- minimingo fails on dotted queries if undefined
 is seen

---
 packages/minimongo/minimongo_tests.js | 8 ++++++++
 packages/minimongo/selector.js        | 8 +++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/packages/minimongo/minimongo_tests.js b/packages/minimongo/minimongo_tests.js
index 13aaaf471a..b27de3a4a5 100644
--- a/packages/minimongo/minimongo_tests.js
+++ b/packages/minimongo/minimongo_tests.js
@@ -532,6 +532,14 @@ Tinytest.add("minimongo - selector_compiler", function (test) {
   match({"a.b": /a/}, {a: {b: "cat"}});
   nomatch({"a.b": /a/}, {a: {b: "dog"}});
 
+  // trying to access a dotted field that is undefined at some point
+  // down the chain
+  nomatch({"a.b": 1}, {x: 2});
+  nomatch({"a.b.c": 1}, {a: {x: 2}});
+  nomatch({"a.b.c": 1}, {a: {b: {x: 2}}});
+  nomatch({"a.b.c": 1}, {a: {b: 1}});
+  nomatch({"a.b.c": 1}, {a: {b: 0}});
+
   // dotted keypaths: literal objects
   match({"a.b": {c: 1}}, {a: {b: {c: 1}}});
   nomatch({"a.b": {c: 1}}, {a: {b: {c: 2}}});
diff --git a/packages/minimongo/selector.js b/packages/minimongo/selector.js
index 90fb8b3e87..00f2c3828f 100644
--- a/packages/minimongo/selector.js
+++ b/packages/minimongo/selector.js
@@ -384,20 +384,22 @@ LocalCollection._exprForKeypathPredicate = function (keypath, value, literals) {
   }
 
   // now, deal with the orthogonal concern of dotted.key.paths and the
-  // (potentially multi-level) array searching they require
+  // (potentially multi-level) array searching they require.
+  // while at it, make sure to not throw an exception if we hit undefined while
+  // drilling down through the dotted parts
   var ret = '';
   var innermost = true;
   while (keyparts.length) {
     var part = keyparts.pop();
     var formal = keyparts.length ? "x" : "doc";
     if (innermost) {
-      ret = '(function(x){return ' + predcode + ';})(' + formal + '[' +
+      ret = '(function(x){return ' + predcode + ';})(' + formal + '&&' + formal + '[' +
         JSON.stringify(part) + '])';
       innermost = false;
     } else {
       // for all but the innermost level of a dotted expression,
       // if the runtime type is an array, search it
-      ret = 'f._matches(' + formal + '[' + JSON.stringify(part) +
+      ret = 'f._matches(' + formal + '&&' + formal + '[' + JSON.stringify(part) +
         '], function(x){return ' + ret + ';})';
     }
   }