fixes #993

tests/template/tissue993.nim

@@ -0,0 +1,21 @@
+
+type pnode* = ref object of tobject
+
+template litNode (name, ty): stmt  =
+  type name* = ref object of PNode
+    val*: ty
+litNode PIntNode, int
+
+import json
+
+template withKey*(j: PJsonNode; key: string; varname: expr;
+                  body:stmt): stmt {.immediate.} =
+  if j.hasKey(key):
+    let varname{.inject.}= j[key]
+    block:
+      body
+
+var j = parsejson("{\"zzz\":1}")
+withkey(j, "foo", x):
+  echo(x)
+