wgl: Fail gracefully whenever 3D could not be enabled for some reason.

src/gallium/state_trackers/wgl/stw_context.c

@@ -75,6 +75,9 @@ DrvCopyContext(
    struct stw_context *dst;
    BOOL ret = FALSE;
 
+   if (!stw_dev)
+      return FALSE;
+
    pipe_mutex_lock( stw_dev->ctx_mutex );
    
    src = stw_lookup_context_locked( dhrcSource );
@@ -102,6 +105,9 @@ DrvShareLists(
    struct stw_context *ctx2;
    BOOL ret = FALSE;
 
+   if (!stw_dev)
+      return FALSE;
+
    pipe_mutex_lock( stw_dev->ctx_mutex );
    
    ctx1 = stw_lookup_context_locked( dhglrc1 );

src/gallium/state_trackers/wgl/stw_framebuffer.c

@@ -179,7 +179,7 @@ stw_call_window_proc(
    if(!tls_data)
       return 0;
    
-   if (nCode < 0)
+   if (nCode < 0 || !stw_dev)
        return CallNextHookEx(tls_data->hCallWndProcHook, nCode, wParam, lParam);
 
    if (pParams->message == WM_WINDOWPOSCHANGED) {
@@ -332,6 +332,9 @@ stw_framebuffer_cleanup( void )
    struct stw_framebuffer *fb;
    struct stw_framebuffer *next;
 
+   if (!stw_dev)
+      return;
+
    pipe_mutex_lock( stw_dev->fb_mutex );
 
    fb = stw_dev->fb_head;
@@ -387,6 +390,9 @@ stw_framebuffer_from_hdc(
 {
    struct stw_framebuffer *fb;
 
+   if (!stw_dev)
+      return NULL;
+
    pipe_mutex_lock( stw_dev->fb_mutex );
    fb = stw_framebuffer_from_hdc_locked(hdc);
    pipe_mutex_unlock( stw_dev->fb_mutex );
@@ -421,6 +427,9 @@ DrvSetPixelFormat(
    uint index;
    struct stw_framebuffer *fb;
 
+   if (!stw_dev)
+      return FALSE;
+
    index = (uint) iPixelFormat - 1;
    count = stw_pixelformat_get_extended_count();
    if (index >= count)
@@ -475,6 +484,9 @@ DrvPresentBuffers(HDC hdc, PGLPRESENTBUFFERSDATA data)
    struct pipe_screen *screen;
    struct pipe_surface *surface;
 
+   if (!stw_dev)
+      return FALSE;
+
    fb = stw_framebuffer_from_hdc( hdc );
    if (fb == NULL)
       return FALSE;
@@ -576,6 +588,9 @@ DrvSwapBuffers(
    struct stw_framebuffer *fb;
    struct pipe_surface *surface = NULL;
 
+   if (!stw_dev)
+      return FALSE;
+
    fb = stw_framebuffer_from_hdc( hdc );
    if (fb == NULL)
       return FALSE;

src/gallium/state_trackers/wgl/stw_getprocaddress.c

@@ -34,6 +34,8 @@
 
 #include "glapi/glapi.h"
 #include "stw_ext_gallium.h"
+#include "stw_device.h"
+#include "stw_icd.h"
 
 struct stw_extension_entry
 {
@@ -73,6 +75,9 @@ DrvGetProcAddress(
 {
    const struct stw_extension_entry *entry;
 
+   if (!stw_dev)
+      return NULL;
+
    if (lpszProc[0] == 'w' && lpszProc[1] == 'g' && lpszProc[2] == 'l')
       for (entry = stw_extension_entries; entry->name; entry++)
          if (strcmp( lpszProc, entry->name ) == 0)

src/gallium/state_trackers/wgl/stw_pixelformat.c

@@ -302,6 +302,9 @@ DrvDescribePixelFormat(
 
    (void) hdc;
 
+   if (!stw_dev)
+      return 0;
+
    count = stw_pixelformat_get_extended_count();
    index = (uint) iPixelFormat - 1;