ui/console: fix qemu_console_resize() regression

The display may be corrupted when changing screen colour depth in
qemu-system-ppc/MacOS since 7.0.

Do not short-cut qemu_console_resize() if the surface is backed by vga
vram. When the scanout isn't set, or it is already allocated, or opengl,
and the size is fitting, we still avoid the reallocation & replace path.

Fixes: commit cb8962c1 ("ui: do not create a surface when resizing a GL scanout")

Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20220725115815.2461322-1-marcandre.lureau@redhat.com>

ui/console.c

@@ -2575,11 +2575,13 @@ static void vc_chr_open(Chardev *chr,
 
 void qemu_console_resize(QemuConsole *s, int width, int height)
 {
-    DisplaySurface *surface;
+    DisplaySurface *surface = qemu_console_surface(s);
 
     assert(s->console_type == GRAPHIC_CONSOLE);
 
-    if (qemu_console_get_width(s, -1) == width &&
+    if ((s->scanout.kind != SCANOUT_SURFACE ||
+         (surface && surface->flags & QEMU_ALLOCATED_FLAG)) &&
+        qemu_console_get_width(s, -1) == width &&
         qemu_console_get_height(s, -1) == height) {
         return;
     }