Fix SymbolItem#hitTestAll()

Closes #1680

src/item/SymbolItem.js

@@ -121,7 +121,16 @@ var SymbolItem = Item.extend(/** @lends SymbolItem# */{
     },
 
     _hitTestSelf: function(point, options, viewMatrix) {
+        // We need to call definition item hit test with `options.all`
+        // disabled, otherwise it would populate the array with its own
+        // matches. What we want instead is only returning one match per symbol
+        // item (#1680). So we store original matches array...
+        var all = options.all;
+        // ...we temporarily disable `options.all`...
+        delete options.all;
         var res = this._definition._item._hitTest(point, options, viewMatrix);
+        // ...then after hit testing, we restore the original matches array.
+        options.all = all;
         // TODO: When the symbol's definition is a path, should hitResult
         // contain information like HitResult#curve?
         if (res)

test/tests/SymbolItem.js

@@ -143,3 +143,18 @@ test('SymbolItem#bounds with #applyMatrix = false', function() {
     equals(function() { return placed.bounds; },
         { x: 150, y: 150, width: 100, height: 100 });
 });
+
+test('SymbolItem#hitTestAll', function() {
+    var symbol = new SymbolDefinition(
+        new Path.Circle({
+            center: [0, 0],
+            radius: 10,
+            fillColor: 'orange'
+        })
+    );
+    var symbolItem = symbol.place([50, 50]);
+
+    var hitTestAll = symbolItem.hitTestAll([50, 50]);
+    equals(hitTestAll.length, 1);
+    equals(hitTestAll[0].item.id, symbolItem.id);
+});