From 5e4dd571d43c904c989c1a256f53df38672a20fe Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Sat, 8 Oct 2022 23:38:22 +0800
Subject: [PATCH] fixes #20516; system.create doesn't work with bitfield
 objects (#20518)

* Revert "fixes #19000 (#19032)"

This reverts commit 2bda4a30a6b12dd0840dc347e454e54fe26721e7.

* fixes #20516; add testcase
---
 lib/system/memalloc.nim  | 6 ------
 tests/stdlib/tsystem.nim | 7 +++++++
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/lib/system/memalloc.nim b/lib/system/memalloc.nim
index 49766e69db4d..f8ebc8c5f669 100644
--- a/lib/system/memalloc.nim
+++ b/lib/system/memalloc.nim
@@ -116,9 +116,6 @@ when hasAlloc and not defined(js):
     ##
     ## See also:
     ## * `create <#create,typedesc>`_
-    static:
-      when sizeof(T) <= 0:
-        {.fatal: "createU does not support types T where sizeof(T) == 0".}
     cast[ptr T](alloc(T.sizeof * size))
 
   template alloc0*(size: Natural): pointer =
@@ -144,9 +141,6 @@ when hasAlloc and not defined(js):
     ##
     ## The allocated memory belongs to its allocating thread!
     ## Use `createShared <#createShared,typedesc>`_ to allocate from a shared heap.
-    static:
-      when sizeof(T) <= 0:
-        {.fatal: "create does not support types T where sizeof(T) == 0".}
     cast[ptr T](alloc0(sizeof(T) * size))
 
   template realloc*(p: pointer, newSize: Natural): pointer =
diff --git a/tests/stdlib/tsystem.nim b/tests/stdlib/tsystem.nim
index 1a976f7a2ea1..810c3af0468f 100644
--- a/tests/stdlib/tsystem.nim
+++ b/tests/stdlib/tsystem.nim
@@ -162,3 +162,10 @@ block:
   reset(y)
   doAssert y.b == {}
 
+block: # bug #20516
+  type Foo = object
+    x {.bitsize:4.}: uint
+    y {.bitsize:4.}: uint
+
+  when not defined(js):
+    let a = create(Foo)