rem: wwarning("ColorPanel: X said I cannot grab a subimage from screen.");
add: wwarning(X_ERR);
context: magnifyGetImage(WMScreen *scr, XImage *image, int x, int y, int w, int h) {    int		x0 = 0,	y0 = 0,	w0 = w,	h0 = h;     const int	displayWidth = DisplayWidth(scr->display, scr->screen),		displayHeight = DisplayHeight(scr->display, scr->screen);        if (!(image && image->data)) {	/* The image in panel->magnifyGlass->image does not exist yet.	 * Grab one from the screen (not beyond) and use it from now on.	 */	if (!(image = XGetImage(scr->display, scr->rootWin,		x - Cursor_x_hot,		y - Cursor_y_hot,		w, h, AllPlanes, ZPixmap)))	    wwarning("ColorPanel: X said I cannot grab an image from screen.");	return image;    }        /* Coordinate correction for back pixmap      * if magnifying glass is at screen-borders      */        /* Figure 1: Shifting of rectangle-to-grab at top/left screen borders     * Hatched area is beyond screen border.     *      * |<-Cursor_x_hot->|     *  ________________|_____      * |/ / / / / / /|  |     |     * | / / / / / / |(x,y)   |     * |/_/_/_/_/_/_/|________|     * |<----x0----->|<--w0-->|     *               0     */    /* Figure 2: Shifting of rectangle-to-grab at bottom/right     * screen borders     * Hatched area is beyond screen border     *     * |<-Cursor_x_hot->|     *  ________________|_______________      * |                |  | / / / / / /|     * |              (x,y)|/ / / / / / |     * |___________________|_/_/_/_/_/_/|     * |<-------w0-------->|            |     * |<---------------w--|----------->|     * |                   |     * x0                  Displaywidth-1     */					      if (x < Cursor_x_hot) {				/* see fig. 1 */	x0 = Cursor_x_hot - x;	w0 = w - x0;    }     if (displayWidth -1 < x - Cursor_x_hot + w) {	/* see fig. 2 */	w0 = (displayWidth) - (x - Cursor_x_hot);    }						      if (y < Cursor_y_hot) {				/* see fig. 1 */	y0 = Cursor_y_hot - y;	h0 = h - y0;    }        if (displayHeight -1 < y - Cursor_y_hot + h) {	/* see fig. 2 */	h0 = (displayHeight) - (y - Cursor_y_hot);    }    /* end of coordinate correction */           /* Grab an image from the screen, clipped if necessary,      * and put it in the existing panel->magnifyGlass->image     * with the corresponding clipping offset.     */    if (!XGetSubImage(scr->display, scr->rootWin, 		x - Cursor_x_hot + x0,		y - Cursor_y_hot + y0,		w0, h0,	AllPlanes, ZPixmap,		image, x0, y0))	wwarning("ColorPanel: X said I cannot grab a subimage from screen.");        return NULL;}