[PATCH v2 2/2] wing32: Avoid crash in WinGGetDIBPointer when called with NULL bitmap info.

[Bernhard Übelacker]

From: Bernhard Übelacker

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=56135
---
 dlls/wing32/tests/wing32.c | 3 +++
 dlls/wing32/wing32.c       | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/dlls/wing32/tests/wing32.c b/dlls/wing32/tests/wing32.c
index 1a3c958ff02..e3f01ff22bc 100644
--- a/dlls/wing32/tests/wing32.c
+++ b/dlls/wing32/tests/wing32.c
@@ -51,6 +51,9 @@ static void test_WinGGetDIBPointer(void)
     dib = WinGGetDIBPointer(NULL, NULL);
     ok(dib == NULL, "WinGGetDIBPointer returned unexpected value %p\n", dib);

+    dib = WinGGetDIBPointer(bmp, NULL);
+    ok(dib != NULL, "WinGGetDIBPointer failed\n");
+
     dib = WinGGetDIBPointer(bmp, &bmi);
     ok(dib != NULL, "WinGGetDIBPointer failed\n");

diff --git a/dlls/wing32/wing32.c b/dlls/wing32/wing32.c
index b6702ba8017..14012206286 100644
--- a/dlls/wing32/wing32.c
+++ b/dlls/wing32/wing32.c
@@ -72,7 +72,7 @@ void * WINAPI WinGGetDIBPointer( HBITMAP hbmp, BITMAPINFO *bmi )

if (GetObjectW( hbmp, sizeof(ds), &ds ) == sizeof(ds))
     {
-        bmi->bmiHeader = ds.dsBmih;
+        if (bmi) bmi->bmiHeader = ds.dsBmih;
         return ds.dsBm.bmBits;
     }
     return NULL;