From 6e1444a2d4a7585e199f3e8cc01844362e6358c7 Mon Sep 17 00:00:00 2001
From: Francisco Casas franciscojacb@gmail.com Date: Fri, 22 Oct 2021 14:21:30 -0300 Subject: [PATCH] gdi32: Fixed obj_map_cmp special cases. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
Fixed obj_map_cmp when the difference between key and entry is too large and the resulting integer overflows.
e.g. The subtraction:
0x000000000A0A009F - 0xFFFFFFFF9910019E
doesn't result in -1 as it should (even when using the highwords 0A0A009F - 9910019E).
Also, by suggestion of Zebediah Figura, pointers are now cast to (UINT_PTR) instead of using HandleToLong(ยท), to avoid a theoretical chance of collision by only using the highwords.
Signed-off-by: Francisco Casas franciscojacb@gmail.com --- dlls/gdi32/objects.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/dlls/gdi32/objects.c b/dlls/gdi32/objects.c index 4b390aa0160..c92a83bdebc 100644 --- a/dlls/gdi32/objects.c +++ b/dlls/gdi32/objects.c @@ -178,7 +178,11 @@ DWORD WINAPI GetObjectType( HGDIOBJ handle ) static int obj_map_cmp( const void *key, const struct wine_rb_entry *entry ) { struct obj_map_entry *obj_entry = WINE_RB_ENTRY_VALUE( entry, struct obj_map_entry, entry ); - return HandleToLong( key ) - HandleToLong( obj_entry->obj ); + UINT_PTR a = (UINT_PTR)(key); + UINT_PTR b = (UINT_PTR)(obj_entry->obj); + if(a>b) return 1; + if(a<b) return -1; + return 0; };
struct wine_rb_tree obj_map = { obj_map_cmp };