gdi32: Don't let the gdi32 driver allocate memory in the dplayx region.

[Alexei Svitkine]

Don't let the gdi32 driver allocate memory in the dplayx region.

Fixes bug: http://bugs.winehq.org/show_bug.cgi?id=34095

The issue is that the dplayx code in wine needs to allocate some
memory at a static address (0x50000000) and loading the Mac native gdi
driver ends up using that part of the address space.

This patch fixes that by reserving that part of memory while the
display driver is initialized and releasing it after.

---
 dlls/gdi32/driver.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/dlls/gdi32/driver.c b/dlls/gdi32/driver.c
index f625f32..e0b0673 100644
--- a/dlls/gdi32/driver.c
+++ b/dlls/gdi32/driver.c
@@ -105,9 +105,16 @@ static const struct gdi_dc_funcs *get_display_driver( HMODULE *module_ret )
     char buffer[MAX_PATH], libname[32], *name, *next;
     HMODULE module = 0;
     HKEY hkey;
+    LPVOID reserved_region;
 
     if (display_driver) goto done;
 
+    /* Reserve a region of memory that may need to be free later for loading dplayx
+     * (see dplayx_global.c), to prevent the display driver allocating memory there.
+     * Release it after the display driver has been initialized.
+     */
+    reserved_region = VirtualAlloc( (LPVOID)0x50000000, 1024 * 1024, MEM_RESERVE, PAGE_NOACCESS );
+
     strcpy( buffer, default_driver );
     /* @@ Wine registry key: HKCU\Software\Wine\Drivers */
     if (!RegOpenKeyA( HKEY_CURRENT_USER, "Software\\Wine\\Drivers", &hkey ))
@@ -142,6 +149,9 @@ static const struct gdi_dc_funcs *get_display_driver( HMODULE *module_ret )
         FreeLibrary( driver->module );
         HeapFree( GetProcessHeap(), 0, driver );
     }
+
+    if (reserved_region) VirtualFree( reserved_region, 0, MEM_RELEASE );
+
 done:
     *module_ret = display_driver->module;
     return display_driver->funcs;