fixes #376

tests/gc/closureleak.nim

@@ -0,0 +1,33 @@
+discard """
+  outputsub: "true"
+"""
+
+from strutils import join
+
+type
+  TFoo * = object
+    id: int
+    func: proc(){.closure.}
+var foo_counter = 0
+var alive_foos = newseq[int](0)
+
+proc free*(some: ref TFoo) =
+  #echo "Tfoo #", some.id, " freed"
+  alive_foos.del alive_foos.find(some.id)
+proc newFoo*(): ref TFoo =
+  new result, free
+  
+  result.id = foo_counter
+  alive_foos.add result.id
+  inc foo_counter
+
+for i in 0 .. <10:
+ discard newFoo()
+
+for i in 0 .. <10:
+  let f = newFoo()
+  f.func = proc = 
+    echo f.id
+
+gc_fullcollect()
+echo alive_foos.len <= 2