In #38924, Tapps 2, DirMaster, and even wxWidgets' sample code (and thus probably many more wxWidgets applications out in the field), all crash during drag-and-drop with custom formats, which they use to implement within-application actions such as rearranging shapes and moving text.
Luckily wxWidgets is our dog food and builds easily, so it could be patched to investigate.
It turns out that wxWidgets expects HeapSize() to succeed on the pointer to global memory returned by GlobalLock(). On Wine this fails, causing wxWidgets to pass a NULL pointer to the application for the drag-and-drop data. Application accesses NULL pointer -> crash.
This patch adds a test for this problem.
Signed-off-by: Damjan Jovanovic damjan.jov@gmail.com --- dlls/kernel32/tests/heap.c | 10 ++++++++++ 1 file changed, 10 insertions(+)