resolve conflict; ref #3286

mrbgems/mruby-compiler/core/codegen.c

@@ -1362,6 +1362,10 @@ codegen(codegen_scope *s, node *tree, int val)
       int pos1, pos2;
       node *e = tree->cdr->cdr->car;
 
+      if (!tree->car) {
+        codegen(s, e, val);
+        return;
+      }
       switch ((intptr_t)tree->car->car) {
       case NODE_TRUE:
       case NODE_INT:

test/t/codegen.rb

@@ -9,3 +9,7 @@ assert('peephole optimization does not eliminate move whose result is reused') d
     method(&a &&= 0)
   end
 end
+
+assert('empty condition in ternary expression parses correctly') do
+  assert_equal(() ? 1 : 2, 2)
+end