[PATCH 0/1] MR10022: gdiplus: Allow GdipBitmapLockBits without read/write flags.

[Bernhard Übelacker (＠bernhardu)]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=59362

[Testbot run with this patch](https://testbot.winehq.org/JobDetails.pl?Key=161700)

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10022

[PATCH 1/1] gdiplus: Allow GdipBitmapLockBits without read/write flags.

[Bernhard Übelacker]

From: Bernhard Übelacker <[e-mail]>

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=59362
---
 dlls/gdiplus/image.c       |  2 +-
 dlls/gdiplus/tests/image.c | 39 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/dlls/gdiplus/image.c b/dlls/gdiplus/image.c
index 2449e2ec863..035db159d5b 100644
--- a/dlls/gdiplus/image.c
+++ b/dlls/gdiplus/image.c
@@ -1125,7 +1125,7 @@ GpStatus WINGDIPAPI GdipBitmapLockBits(GpBitmap* bitmap, GDIPCONST GpRect* rect,
 
     if(rect){
         if(rect->X < 0 || rect->Y < 0 || (rect->X + rect->Width > bitmap->width) ||
-          (rect->Y + rect->Height > bitmap->height) || !flags)
+          (rect->Y + rect->Height > bitmap->height))
         {
             image_unlock(&bitmap->image);
             return InvalidParameter;
diff --git a/dlls/gdiplus/tests/image.c b/dlls/gdiplus/tests/image.c
index e3602ceb505..db4a56bf859 100644
--- a/dlls/gdiplus/tests/image.c
+++ b/dlls/gdiplus/tests/image.c
@@ -901,6 +901,27 @@ static void test_LockBits(void)
     stat = GdipBitmapSetPixel(bm, 2, 8, 0xff480000);
     expect(Ok, stat);
 
+    /* no read/write flags */
+    stat = GdipBitmapLockBits(bm, &rect, 0, PixelFormat24bppRGB, &bd);
+    expect(Ok, stat);
+
+    if (stat == Ok) {
+        expect(0xc3, ((BYTE*)bd.Scan0)[2]);
+        expect(0x48, ((BYTE*)bd.Scan0)[2 + bd.Stride * 5]);
+
+        ((char*)bd.Scan0)[2] = 0xfe;
+
+        stat = GdipBitmapUnlockBits(bm, &bd);
+        expect(Ok, stat);
+    }
+
+    stat = GdipBitmapGetPixel(bm, 2, 3, &color);
+    expect(Ok, stat);
+    expect(0xfffe0000, color);
+
+    stat = GdipBitmapSetPixel(bm, 2, 3, 0xffc30000);
+    expect(Ok, stat);
+
     /* read-only */
     stat = GdipBitmapLockBits(bm, &rect, ImageLockModeRead, PixelFormat24bppRGB, &bd);
     expect(Ok, stat);
@@ -1142,6 +1163,24 @@ static void test_LockBits_UserBuf(void)
     bd.Scan0 = &bits[2+3*WIDTH];
     bd.Reserved = 0xaaaaaaaa;
 
+    /* no read/write flags */
+    stat = GdipBitmapLockBits(bm, &rect, ImageLockModeUserInputBuf, PixelFormat32bppARGB, &bd);
+    expect(Ok, stat);
+
+    expect(0xaaaaaaaa, bits[0]);
+    expect(0xaaaaaaaa, bits[2+3*WIDTH]);
+
+    bits[2+3*WIDTH] = 0xdeadbeef;
+
+    if (stat == Ok) {
+        stat = GdipBitmapUnlockBits(bm, &bd);
+        expect(Ok, stat);
+    }
+
+    stat = GdipBitmapGetPixel(bm, 2, 3, &color);
+    expect(Ok, stat);
+    expect(0, color);
+
     /* read-only */
     stat = GdipBitmapLockBits(bm, &rect, ImageLockModeRead|ImageLockModeUserInputBuf, PixelFormat32bppARGB, &bd);
     expect(Ok, stat);
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10022

[Esme Povirk (＠madewokherd)]

We should also test this while requesting a different pixel format so that a conversion is required. It's possible that it isn't "supposed" to allow writing, but native has an optimization (which we must copy) where it will point the caller directly to the bitmap's buffer, which allows writing even when the flag isn't specified.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10022#note_128988