Fix call function incorrectly epanding map arguments

Author: xzyfer

bind.cpp

@@ -56,6 +56,20 @@ namespace Sass {
           else {
             env->local_frame()[p->name()] = a->value();
           }
+        } else if (a->is_keyword_argument()) {
+
+          // expand keyword arguments into their parameters
+          List* arglist = new (ctx.mem) List(p->pstate(), 0, List::COMMA, true);
+          env->local_frame()[p->name()] = arglist;
+          Map* argmap = static_cast<Map*>(a->value());
+          for (auto key : argmap->keys()) {
+            string name = unquote(static_cast<String_Constant*>(key)->value());
+            (*arglist) << new (ctx.mem) Argument(key->pstate(),
+                                                 argmap->at(key),
+                                                 name,
+                                                 false);
+          }
+
         } else {
 
           // copy all remaining arguments into the rest parameter, preserving names

functions.cpp

@@ -1474,7 +1474,7 @@ namespace Sass {
       for (size_t i = 0, L = arglist->length(); i < L; ++i) {
         Expression* expr = arglist->value_at_index(i);
         if (arglist->is_arglist()) {
-           Argument* arg = static_cast<Argument*>(expr);
+          Argument* arg = static_cast<Argument*>((*arglist)[i]);
           *args << new (ctx.mem) Argument(pstate,
                                           expr,
                                           "",