fixed getParameterString to handle null/undefined values correctly. r=elemoine (closes #2157)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@9573 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Util.js

@@ -608,8 +608,12 @@ OpenLayers.Util.getParameterString = function(params) {
         if (typeof value == 'object' && value.constructor == Array) {
           /* value is an array; encode items and separate with "," */
           var encodedItemArray = [];
+          var item;
           for (var itemIndex=0, len=value.length; itemIndex<len; itemIndex++) {
-            encodedItemArray.push(encodeURIComponent(value[itemIndex]));
+            item = value[itemIndex];
+            encodedItemArray.push(encodeURIComponent(
+                (item === null || item === undefined) ? "" : item)
+            );
           }
           encodedValue = encodedItemArray.join(",");
         }

tests/Util.html

@@ -225,7 +225,7 @@
     }
 
     function test_Util_getParameterString(t) {
-        t.plan( 4 );
+        t.plan( 5 );
 
         var params = { 
             'foo': "bar",
@@ -243,6 +243,9 @@
         
         var params = { foo: ["bar","baz,"] };
         t.eq( OpenLayers.Util.getParameterString(params), "foo=bar,baz%2C", "getParameterString returns with list of CSVs when given a list. ");
+        
+        var params = { foo: [null, undefined, 0, "", "bar"] }
+        t.eq( OpenLayers.Util.getParameterString(params), "foo=,,0,,bar", "getParameterString works fine with null values in array.");
     }
 
     function test_Util_createAlphaImageDiv(t) {