Prevent some more crashes

gfx/drivers_font/gl_raster_font.c

@@ -200,7 +200,7 @@ static int gl_get_message_width(void *data, const char *msg,
    unsigned msg_len = min(msg_len_full, MAX_MSG_LEN_CHUNK);
    int      delta_x = 0;
 
-   if (!font)
+   if (!font || !font->font_driver)
       return 0;
 
    while (msg_len_full)
@@ -209,6 +209,7 @@ static int gl_get_message_width(void *data, const char *msg,
       {
          const struct font_glyph *glyph = 
             font->font_driver->get_glyph(font->font_data, (uint8_t)msg[i]);
+
          if (!glyph) /* Do something smarter here ... */
             glyph = font->font_driver->get_glyph(font->font_data, '?');
          if (!glyph)
@@ -340,7 +341,11 @@ static void gl_raster_font_render_message(
    int lines = 0;
    float line_height;
 
-   if (!msg || !*msg || !font->gl)
+   if (     !msg 
+         || !*msg 
+         || !font->gl 
+         || !font 
+         || !font->font_driver)
       return;
 
    /* If the font height is not supported just draw as usual */

gfx/drivers_font_renderer/freetype.c

@@ -233,11 +233,10 @@ static const char *font_renderer_ft_get_default_font(void)
 
 static int font_renderer_ft_get_line_height(void* data)
 {
-    ft_font_renderer_t *handle = (ft_font_renderer_t*)data;
-    if (!handle)
+   ft_font_renderer_t *handle = (ft_font_renderer_t*)data;
+   if (!handle || !handle->face)
       return 0;
-      
-    return handle->face->size->metrics.height/64;
+   return handle->face->size->metrics.height/64;
 }
 
 font_renderer_driver_t freetype_font_renderer = {

menu/drivers/zarch.c

@@ -861,6 +861,9 @@ static int zarch_zui_render_lay_root(zui_t *zui)
    tabbed.width            = zui->width - 290 - 40;
    zui->next_selection_set = false;
 
+   if (!zui)
+      return 1;
+
    if (zarch_zui_render_lay_root_recent(zui, &tabbed))
       return 0;
    if (zarch_zui_render_lay_root_load  (zui, &tabbed))