From 3424dac3863f57c5d9724a31744469b9fcd4bd89 Mon Sep 17 00:00:00 2001
From: Vincent Povirk <vincent@codeweavers.com>
Date: Sat, 12 Dec 2009 17:13:39 -0600
Subject: [PATCH] gdiplus: Explicitly copy the bits from dib sections to new
 bitmaps.

On Windows, GdipCreateBitmapFromHBITMAP creates a copy of the bitmap, not
a reference. Currently, we match this behavior, but this is only because
we cannot yet create bitmap objects that reference existing memory. If
GdipCreateBitmapFromScan0 were fixed to do this, FromHBITMAP would break.

Therefore, we always pass NULL to FromScan0 so that it allocates new memory
for the bitmap.
---
 dlls/gdiplus/image.c       | 37 +++++++++++++++++++++++++++----------
 dlls/gdiplus/tests/image.c | 13 ++++++++++++-
 2 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/dlls/gdiplus/image.c b/dlls/gdiplus/image.c
index f78b70aa891..aa03712b9f0 100644
--- a/dlls/gdiplus/image.c
+++ b/dlls/gdiplus/image.c
@@ -2659,7 +2659,8 @@ GpStatus WINGDIPAPI GdipCreateBitmapFromHBITMAP(HBITMAP hbm, HPALETTE hpal, GpBi
     BITMAP bm;
     GpStatus retval;
     PixelFormat format;
-    BYTE* bits;
+    BitmapData lockeddata;
+    INT y;
 
     TRACE("%p %p %p\n", hbm, hpal, bitmap);
 
@@ -2700,16 +2701,32 @@ GpStatus WINGDIPAPI GdipCreateBitmapFromHBITMAP(HBITMAP hbm, HPALETTE hpal, GpBi
             return InvalidParameter;
     }
 
-    if (bm.bmBits)
-        bits = (BYTE*)bm.bmBits + (bm.bmHeight - 1) * bm.bmWidthBytes;
-    else
-    {
-        FIXME("can only get image data from DIB sections\n");
-        bits = NULL;
-    }
+    retval = GdipCreateBitmapFromScan0(bm.bmWidth, bm.bmHeight, 0,
+        format, NULL, bitmap);
 
-    retval = GdipCreateBitmapFromScan0(bm.bmWidth, bm.bmHeight, -bm.bmWidthBytes,
-        format, bits, bitmap);
+    if (retval == Ok)
+    {
+        retval = GdipBitmapLockBits(*bitmap, NULL, ImageLockModeWrite,
+            format, &lockeddata);
+        if (retval == Ok)
+        {
+            if (bm.bmBits)
+            {
+                for (y=0; y<bm.bmHeight; y++)
+                {
+                    memcpy((BYTE*)lockeddata.Scan0+lockeddata.Stride*y,
+                           (BYTE*)bm.bmBits+bm.bmWidthBytes*(bm.bmHeight-1-y),
+                           bm.bmWidthBytes);
+                }
+            }
+            else
+            {
+                FIXME("can only get image data from DIB sections\n");
+            }
+
+            GdipBitmapUnlockBits(*bitmap, &lockeddata);
+        }
+    }
 
     return retval;
 }
diff --git a/dlls/gdiplus/tests/image.c b/dlls/gdiplus/tests/image.c
index 1ef2651da4a..66c6410ba13 100644
--- a/dlls/gdiplus/tests/image.c
+++ b/dlls/gdiplus/tests/image.c
@@ -465,6 +465,7 @@ static void test_GdipCreateBitmapFromHBITMAP(void)
     const REAL HEIGHT2 = 20;
     HDC hdc;
     BITMAPINFO bmi;
+    BYTE *bits;
 
     stat = GdipCreateBitmapFromHBITMAP(NULL, NULL, NULL);
     expect(InvalidParameter, stat);
@@ -504,16 +505,26 @@ static void test_GdipCreateBitmapFromHBITMAP(void)
     bmi.bmiHeader.biPlanes = 1;
     bmi.bmiHeader.biCompression = BI_RGB;
 
-    hbm = CreateDIBSection(hdc, &bmi, DIB_RGB_COLORS, NULL, NULL, 0);
+    hbm = CreateDIBSection(hdc, &bmi, DIB_RGB_COLORS, (void**)&bits, NULL, 0);
     ok(hbm != NULL, "CreateDIBSection failed\n");
 
+    bits[0] = 0;
+
     stat = GdipCreateBitmapFromHBITMAP(hbm, NULL, &gpbm);
     expect(Ok, stat);
     expect(Ok, GdipGetImageDimension((GpImage*) gpbm, &width, &height));
     expectf(WIDTH1,  width);
     expectf(HEIGHT1, height);
     if (stat == Ok)
+    {
+        /* test whether writing to the bitmap affects the original */
+        stat = GdipBitmapSetPixel(gpbm, 0, 0, 0xffffffff);
+        expect(Ok, stat);
+
+        expect(0, bits[0]);
+
         GdipDisposeImage((GpImage*)gpbm);
+    }
 
     LogPal = GdipAlloc(sizeof(LOGPALETTE));
     ok(LogPal != NULL, "unable to allocate LOGPALETTE\n");