diff -rup qemu-kvm-0.15.1/hw/vga.c frob/hw/vga.c

--- qemu-kvm-0.15.1/hw/vga.c	2011-10-19 09:54:48.000000000 -0400

+++ frob/hw/vga.c	2012-07-29 21:00:27.389677588 -0400

@@ -149,7 +149,7 @@ static uint16_t expand2[256];

 static uint8_t expand4to8[16];

 static void vga_screen_dump(void *opaque, const char *filename);

-static char *screen_dump_filename;

+static const char *screen_dump_filename;

 static DisplayChangeListener *screen_dump_dcl;

 static void vga_dumb_update_retrace_info(VGACommonState *s)

@@ -2330,7 +2330,6 @@ static void vga_save_dpy_update(DisplayS

 {

     if (screen_dump_filename) {

         ppm_save(screen_dump_filename, ds->surface);

-        screen_dump_filename = NULL;

     }

 }

@@ -2408,8 +2407,8 @@ static void vga_screen_dump(void *opaque

     if (!screen_dump_dcl)

         screen_dump_dcl = vga_screen_dump_init(s->ds);

-    screen_dump_filename = (char *)filename;

+    screen_dump_filename = filename;

     vga_invalidate_display(s);

     vga_hw_update();

+    screen_dump_filename = NULL;

 }

-