From 2039e3e883ac42cd9b6012335a92564ca2b56387 Mon Sep 17 00:00:00 2001
From: Timothee Cour <timothee.cour2@gmail.com>
Date: Fri, 19 Jun 2020 06:08:00 -0700
Subject: [PATCH] fix #13899 defer now works with async (#14723)

---
 lib/pure/asyncmacro.nim     |  3 +++
 tests/async/tasync_misc.nim | 25 ++++++++++++++++++-------
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/lib/pure/asyncmacro.nim b/lib/pure/asyncmacro.nim
index cbed6372c..621a4b00c 100644
--- a/lib/pure/asyncmacro.nim
+++ b/lib/pure/asyncmacro.nim
@@ -207,6 +207,9 @@ proc asyncSingleProc(prc: NimNode): NimNode {.compileTime.} =
                                     futureVarIdents)
   # don't do anything with forward bodies (empty)
   if procBody.kind != nnkEmpty:
+    # fix #13899, defer should not escape its original scope
+    procBody = newStmtList(newTree(nnkBlockStmt, newEmptyNode(), procBody))
+
     procBody.add(createFutureVarCompletions(futureVarIdents, nil))
 
     if not subtypeIsVoid:
diff --git a/tests/async/tasync_misc.nim b/tests/async/tasync_misc.nim
index c5ee22a42..29e6faa72 100644
--- a/tests/async/tasync_misc.nim
+++ b/tests/async/tasync_misc.nim
@@ -1,8 +1,3 @@
-discard """
-  exitcode: 0
-  output: "ok"
-"""
-
 import json, asyncdispatch
 block: #6100
   let done = newFuture[int]()
@@ -61,5 +56,21 @@ block: # 12743
 
   waitFor prc()
 
-
-echo "ok"
+block: # issue #13899
+  proc someConnect() {.async.} =
+    await sleepAsync(1)
+  proc someClose() {.async.} =
+    await sleepAsync(2)
+  proc testFooFails(): Future[bool] {.async.} =
+    await someConnect()
+    defer:
+      await someClose()
+      result = true
+  proc testFooSucceed(): Future[bool] {.async.} =
+    try:
+      await someConnect()
+    finally:
+      await someClose()
+      result = true
+  doAssert waitFor testFooSucceed()
+  doAssert waitFor testFooFails()