1 files changed, 98 insertions, 0 deletions
diff --git a/tests/destructor/tcycle3.nim b/tests/destructor/tcycle3.nim
new file mode 100644
index 000000000..8662136e7
--- /dev/null
+++ b/tests/destructor/tcycle3.nim
@@ -0,0 +1,98 @@
+discard """
+  output: '''BEGIN
+END
+END 2
+cpu.nes false
+cpu step nes is nil? - false
+0'''
+  cmd: '''nim c --gc:orc $file'''
+"""
+
+# extracted from thavlak.nim
+
+type
+  BasicBlock = ref object
+    inEdges: seq[BasicBlock]
+    outEdges: seq[BasicBlock]
+    name: int
+
+proc newBasicBlock(name: int): BasicBlock =
+  result = BasicBlock(
+    inEdges: newSeq[BasicBlock](),
+    outEdges: newSeq[BasicBlock](),
+    name: name
+  )
+
+type
+  Cfg = object
+    basicBlockMap: seq[BasicBlock]
+    startNode: BasicBlock
+
+proc newCfg(): Cfg =
+  result = Cfg(
+    basicBlockMap: newSeq[BasicBlock](),
+    startNode: nil)
+
+proc createNode(cfg: var Cfg, name: int): BasicBlock =
+  if name < cfg.basicBlockMap.len:
+    result = cfg.basicBlockMap[name]
+  else:
+    result = newBasicBlock(name)
+    cfg.basicBlockMap.setLen name+1
+    cfg.basicBlockMap[name] = result
+
+proc newBasicBlockEdge(cfg: var Cfg, fromName, toName: int) =
+  echo "BEGIN"
+  let fr = cfg.createNode(fromName)
+  let to = cfg.createNode(toName)
+
+  fr.outEdges.add(to)
+  to.inEdges.add(fr)
+
+proc run(cfg: var Cfg) =
+  cfg.startNode = cfg.createNode(0) # RC = 2
+  newBasicBlockEdge(cfg, 0, 1) #
+  echo "END"
+
+  discard cfg.createNode(1)
+
+proc main =
+  var c = newCfg()
+  c.run
+  echo "END 2"
+
+# bug #14159
+type
+  NES = ref object
+    cpu: CPU
+    apu: APU
+
+  CPU = ref object
+    nes: NES
+
+  APU = object
+    nes: NES
+    cpu: CPU
+
+proc initAPU(nes: sink NES): APU {.nosinks.} =
+  result.nes = nes
+  result.cpu = nes.cpu
+
+proc step(cpu: CPU): int =
+  echo "cpu.nes ", cpu.isNil
+  echo "cpu step nes is nil? - ", cpu.nes.isNil()
+
+proc newNES(): NES =
+  new result
+  result.cpu = CPU(nes: result)
+  result.apu = initAPU(result)
+
+proc bug14159 =
+  var nesConsole = newNES()
+  discard nesConsole.cpu.step()
+
+let mem = getOccupiedMem()
+main()
+bug14159()
+GC_fullCollect()
+echo getOccupiedMem() - mem