From 7ae9c4358e9385bbcce0b1acd874e3e2a51a1613 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oscar=20Nihlg=C3=A5rd?= <oscarnihlgard@gmail.com>
Date: Sat, 30 Jun 2018 13:38:52 +0200
Subject: [PATCH] Fix vm regression (#8163)

---
 compiler/vm.nim      |  7 +++++++
 tests/vm/tvmmisc.nim | 13 +++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/compiler/vm.nim b/compiler/vm.nim
index 9e5db978cf..7f0dd80edc 100644
--- a/compiler/vm.nim
+++ b/compiler/vm.nim
@@ -622,6 +622,13 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
             stackTrace(c, tos, pc, errNilAccess)
           regs[ra].nodeAddr[][] = n[]
           regs[ra].nodeAddr[].flags.incl nfIsRef
+        # `var object` parameters are sent as rkNodeAddr. When they are mutated
+        # vmgen generates opcWrDeref, which means that we must dereference
+        # twice.
+        # TODO: This should likely be handled differently in vmgen.
+        elif (nfIsRef notin regs[ra].nodeAddr[].flags and
+            nfIsRef notin n.flags):
+          regs[ra].nodeAddr[][] = n[]
         else:
           regs[ra].nodeAddr[] = n
       of rkRegisterAddr: regs[ra].regAddr[] = regs[rc]
diff --git a/tests/vm/tvmmisc.nim b/tests/vm/tvmmisc.nim
index d82c2cf5e2..6a8084647f 100644
--- a/tests/vm/tvmmisc.nim
+++ b/tests/vm/tvmmisc.nim
@@ -135,3 +135,16 @@ static:
   o.pushName()
   o.pushName()
   doAssert o.names == "FOOBARFOOBAR"
+
+# #8154
+import parseutils
+
+static:
+  type Obj = object
+    i: int
+
+  proc foo(): Obj =
+    discard parseInt("1", result.i, 0)
+
+  static:
+    doAssert foo().i == 1