More Windows-DRI Fixes11.2.2-patches

Initialize renderType in driwindows_create_context_attribs()

../../../src/glx/driwindows_glx.c: In function ‘driwindows_create_context_attribs’:
../../../src/glx/driwindows_glx.c:247:9: warning: ‘renderType’ may be used uninitialized in this function [-Wmaybe-uninitialized]

This presumably caused driwindows_create_context_attribs() to usually fail,
causing mesa to fallback to an indirect context, masking other problems with
create_context_attribs().

Fix windows_create_context()/windows_create_context_attribs() to return NULL
on failure, not a broken context.

Fix windows_create_context_attribs() not to deref shared if it is NULL to
indicate no shared context.

2 files changed, 18 insertions, 3 deletions

diff --git a/src/glx/driwindows_glx.c b/src/glx/driwindows_glx.c
index d0f9276ca2..f77b258e19 100644
--- a/src/glx/driwindows_glx.c
+++ b/src/glx/driwindows_glx.c
@@ -224,7 +224,7 @@ driwindows_create_context_attribs(struct glx_screen *base,
    windowsContext *shared = NULL;
 
    int i;
-   uint32_t renderType;
+   uint32_t renderType = GLX_RGBA_TYPE;
 
    /* Extract renderType from attribs */
    for (i = 0; i < num_attribs; i++) {
diff --git a/src/glx/windows/windowsgl.c b/src/glx/windows/windowsgl.c
index be7c31c617..d3f591a28a 100644
--- a/src/glx/windows/windowsgl.c
+++ b/src/glx/windows/windowsgl.c
@@ -107,12 +107,18 @@ windows_create_context(int pxfi, windowsContext *shared)
 
    gc->ctx = wglCreateContext(hdc);
 
-   if (shared)
+   if (shared && gc->ctx)
       wglShareLists(shared->ctx, gc->ctx);
 
    ReleaseDC(hwnd, hdc);
    DestroyWindow(hwnd);
 
+   if (!gc->ctx)
+   {
+     free(gc);
+     return NULL;
+   }
+
    return gc;
 }
 
@@ -155,16 +161,25 @@ windows_create_context_attribs(int pxfi, windowsContext *shared, const int *attr
                                0, 0, 0, 0,
                                NULL, NULL, GetModuleHandle(NULL), NULL);
    HDC hdc = GetDC(hwnd);
+   HGLRC shareContext = NULL;
+   if (shared)
+      shareContext = shared->ctx;
 
    // We must set the windows pixel format before we can create a WGL context
    gc->pxfi = pxfi;
    SetPixelFormat(hdc, gc->pxfi, NULL);
 
-   gc->ctx = wglCreateContextAttribsARB(hdc, shared->ctx, attribList);
+   gc->ctx = wglCreateContextAttribsARB(hdc, shareContext, attribList);
 
    ReleaseDC(hwnd, hdc);
    DestroyWindow(hwnd);
 
+   if (!gc->ctx)
+   {
+     free(gc);
+     return NULL;
+   }
+
    return gc;
 }