From d7d8998d1e38080893ba7b95439b30efc5183b78 Mon Sep 17 00:00:00 2001
From: Huw Davies <huw@codeweavers.com>
Date: Fri, 28 Oct 2005 16:41:25 +0000
Subject: [PATCH] xform can be NULL when setting the identity.

---
 dlls/gdi/dc.c              |  2 +-
 dlls/gdi/tests/.cvsignore  |  1 +
 dlls/gdi/tests/Makefile.in |  1 +
 dlls/gdi/tests/mapping.c   | 59 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 dlls/gdi/tests/mapping.c

diff --git a/dlls/gdi/dc.c b/dlls/gdi/dc.c
index 0fd62812095..8168a13ff36 100644
--- a/dlls/gdi/dc.c
+++ b/dlls/gdi/dc.c
@@ -1217,7 +1217,7 @@ BOOL WINAPI ModifyWorldTransform( HDC hdc, const XFORM *xform,
 
     /* Check for illegal parameters */
     if (!dc) return FALSE;
-    if (!xform) goto done;
+    if (!xform && iMode != MWT_IDENTITY) goto done;
 
     /* Check that graphics mode is GM_ADVANCED */
     if (dc->GraphicsMode!=GM_ADVANCED) goto done;
diff --git a/dlls/gdi/tests/.cvsignore b/dlls/gdi/tests/.cvsignore
index 47ec78485ec..38c8561ef32 100644
--- a/dlls/gdi/tests/.cvsignore
+++ b/dlls/gdi/tests/.cvsignore
@@ -4,6 +4,7 @@ brush.ok
 clipping.ok
 gdiobj.ok
 generated.ok
+mapping.ok
 metafile.ok
 palette.ok
 testlist.c
diff --git a/dlls/gdi/tests/Makefile.in b/dlls/gdi/tests/Makefile.in
index ce36808a21e..6d2516d4ba0 100644
--- a/dlls/gdi/tests/Makefile.in
+++ b/dlls/gdi/tests/Makefile.in
@@ -11,6 +11,7 @@ CTESTS = \
 	clipping.c \
 	gdiobj.c \
 	generated.c \
+	mapping.c \
 	metafile.c \
 	palette.c
 
diff --git a/dlls/gdi/tests/mapping.c b/dlls/gdi/tests/mapping.c
new file mode 100644
index 00000000000..a7fdda92e60
--- /dev/null
+++ b/dlls/gdi/tests/mapping.c
@@ -0,0 +1,59 @@
+/*
+ * Unit tests for mapping functions
+ *
+ * Copyright (c) 2005 Huw Davies
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <math.h>
+
+#include "wine/test.h"
+#include "winbase.h"
+#include "wingdi.h"
+#include "winuser.h"
+#include "winerror.h"
+
+
+void test_modify_world_transform(void)
+{
+    HDC hdc = GetDC(0);
+    int ret;
+
+    ret = SetGraphicsMode(hdc, GM_ADVANCED);
+    if(!ret) /* running in win9x so quit */
+    {
+        ReleaseDC(0, hdc);
+        return;
+    }
+
+    ret = ModifyWorldTransform(hdc, NULL, MWT_IDENTITY);
+    ok(ret, "ret = %d\n", ret);
+
+    ret = ModifyWorldTransform(hdc, NULL, MWT_LEFTMULTIPLY);
+    ok(!ret, "ret = %d\n", ret);
+
+    ret = ModifyWorldTransform(hdc, NULL, MWT_RIGHTMULTIPLY);
+    ok(!ret, "ret = %d\n", ret);
+
+    ReleaseDC(0, hdc);
+}
+
+START_TEST(mapping)
+{
+    test_modify_world_transform();
+}