[PATCH] ui/console: fix three double frees in png_save()

[Volker Rümelin]

The png_destroy_write_struct() function frees all memory used by
libpng. Don't use the glib auto cleanup mechanism to free the
memory allocated by libpng again. For the pixman image, use only the
auto cleanup mechanism and remove the qemu_pixman_image_unref()
function call to prevent another double free.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1210
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
---
 ui/console.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/ui/console.c b/ui/console.c
index 765892f84f..030e75bc71 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -304,8 +304,8 @@ static bool png_save(int fd, pixman_image_t *image, Error 
**errp)
 {
     int width = pixman_image_get_width(image);
     int height = pixman_image_get_height(image);
-    g_autofree png_struct *png_ptr = NULL;
-    g_autofree png_info *info_ptr = NULL;
+    png_struct *png_ptr;
+    png_info *info_ptr = NULL;
     g_autoptr(pixman_image_t) linebuf =
                             qemu_pixman_linebuf_create(PIXMAN_a8r8g8b8, width);
     uint8_t *buf = (uint8_t *)pixman_image_get_data(linebuf);
@@ -346,7 +346,6 @@ static bool png_save(int fd, pixman_image_t *image, Error 
**errp)
         qemu_pixman_linebuf_fill(linebuf, image, width, 0, y);
         png_write_row(png_ptr, buf);
     }
-    qemu_pixman_image_unref(linebuf);
 
     png_write_end(png_ptr, NULL);
 
-- 
2.35.3