glx: Fix drawable lookup bugs in glXUseXFont

We were using the current drawable of the context to name the
appropriate screen for creating the bitmaps. But one, the current
drawable can be None, and two, it can be a GLXDrawable. Passing either
one as the second argument to XCreatePixmap will throw BadDrawable. Use
the root window of the context's screen instead.

Gitlab: https://gitlab.freedesktop.org/mesa/mesa/issues/89
LOLed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>

1 files changed, 6 insertions, 16 deletions

diff --git a/src/glx/xfont.c b/src/glx/xfont.c
index 00498bc3ea4..fdf8f992139 100644
--- a/src/glx/xfont.c
+++ b/src/glx/xfont.c
@@ -129,7 +129,7 @@ dump_bitmap(unsigned int width, unsigned int height, GLubyte * bitmap)
  * Generate OpenGL-compatible bitmap.
  */
 static void
-fill_bitmap(Display * dpy, Window win, GC gc,
+fill_bitmap(Display * dpy, int screen, GC gc,
             unsigned int width, unsigned int height,
             int x0, int y0, unsigned int c, GLubyte * bitmap)
 {
@@ -138,7 +138,7 @@ fill_bitmap(Display * dpy, Window win, GC gc,
    Pixmap pixmap;
    XChar2b char2b;
 
-   pixmap = XCreatePixmap(dpy, win, 8 * width, height, 1);
+   pixmap = XCreatePixmap(dpy, RootWindow(dpy, screen), 8 * width, height, 1);
    XSetForeground(dpy, gc, 0);
    XFillRectangle(dpy, pixmap, gc, 0, 0, 8 * width, height);
    XSetForeground(dpy, gc, 1);
@@ -215,17 +215,13 @@ _X_HIDDEN void
 DRI_glXUseXFont(struct glx_context *CC, Font font, int first, int count, int listbase)
 {
    Display *dpy;
-   Window win;
+   int screen;
    Pixmap pixmap;
    GC gc;
    XGCValues values;
    unsigned long valuemask;
    XFontStruct *fs;
 
-#if !defined(GLX_USE_APPLEGL)
-   __GLXDRIdrawable *glxdraw;
-#endif
-
    GLint swapbytes, lsbfirst, rowlength;
    GLint skiprows, skippixels, alignment;
 
@@ -235,13 +231,7 @@ DRI_glXUseXFont(struct glx_context *CC, Font font, int first, int count, int lis
    int i;
 
    dpy = CC->currentDpy;
-   win = CC->currentDrawable;
-
-#if !defined(GLX_USE_APPLEGL)
-   glxdraw = GetGLXDRIDrawable(CC->currentDpy, CC->currentDrawable);
-   if (glxdraw)
-      win = glxdraw->xDrawable;
-#endif
+   screen = CC->screen;
 
    fs = XQueryFont(dpy, font);
    if (!fs) {
@@ -289,7 +279,7 @@ DRI_glXUseXFont(struct glx_context *CC, Font font, int first, int count, int lis
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
-   pixmap = XCreatePixmap(dpy, win, 10, 10, 1);
+   pixmap = XCreatePixmap(dpy, RootWindow(dpy, screen), 10, 10, 1);
    values.foreground = BlackPixel(dpy, DefaultScreen(dpy));
    values.background = WhitePixel(dpy, DefaultScreen(dpy));
    values.font = fs->fid;
@@ -352,7 +342,7 @@ DRI_glXUseXFont(struct glx_context *CC, Font font, int first, int count, int lis
       if (valid && (bm_width > 0) && (bm_height > 0)) {
 
          memset(bm, '\0', bm_width * bm_height);
-         fill_bitmap(dpy, win, gc, bm_width, bm_height, x, y, c, bm);
+         fill_bitmap(dpy, screen, gc, bm_width, bm_height, x, y, c, bm);
 
          glBitmap(width, height, x0, y0, dx, dy, bm);
 #ifdef DEBUG