fix($resource): null default param results in TypeError

Fixes issue when setting a default param as `null` error
`TypeError: Cannot read property 'charAt' of null`

1 files changed, 1 insertions, 1 deletions

diff --git a/src/ngResource/resource.js b/src/ngResource/resource.js
index a2e915e8..c165ffab 100644
--- a/src/ngResource/resource.js
+++ b/src/ngResource/resource.js
@@ -392,7 +392,7 @@ angular.module('ngResource', ['ng']).
         actionParams = extend({}, paramDefaults, actionParams);
         forEach(actionParams, function(value, key){
           if (isFunction(value)) { value = value(); }
-          ids[key] = value.charAt && value.charAt(0) == '@' ? getter(data, value.substr(1)) : value;
+          ids[key] = value && value.charAt && value.charAt(0) == '@' ? getter(data, value.substr(1)) : value;
         });
         return ids;
       }