Merge remote-tracking branch 'remotes/kraxel/tags/fixes-20210810-pull-request' into staging

fixes for gtk, sdl and audio live migration.

# gpg: Signature made Tue 10 Aug 2021 13:18:30 BST
# gpg:                using RSA key A0328CFFB93A17A79901FE7D4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/fixes-20210810-pull-request:
  ui/sdl2: Check return value from g_setenv()
  audio: Never send migration section
  ui/gtk: retry sending VTE console input

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

audio/audio.c

@@ -1622,10 +1622,20 @@ void audio_cleanup(void)
     }
 }
 
+static bool vmstate_audio_needed(void *opaque)
+{
+    /*
+     * Never needed, this vmstate only exists in case
+     * an old qemu sends it to us.
+     */
+    return false;
+}
+
 static const VMStateDescription vmstate_audio = {
     .name = "audio",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = vmstate_audio_needed,
     .fields = (VMStateField[]) {
         VMSTATE_END_OF_LIST()
     }

ui/gtk.c

@@ -1646,16 +1646,14 @@ static void gd_vc_send_chars(VirtualConsole *vc)
 
     len = qemu_chr_be_can_write(vc->vte.chr);
     avail = fifo8_num_used(&vc->vte.out_fifo);
-    if (len > avail) {
-        len = avail;
-    }
-    while (len > 0) {
+    while (len > 0 && avail > 0) {
         const uint8_t *buf;
         uint32_t size;
 
-        buf = fifo8_pop_buf(&vc->vte.out_fifo, len, &size);
+        buf = fifo8_pop_buf(&vc->vte.out_fifo, MIN(len, avail), &size);
         qemu_chr_be_write(vc->vte.chr, (uint8_t *)buf, size);
-        len -= size;
+        len = qemu_chr_be_can_write(vc->vte.chr);
+        avail -= size;
     }
 }
 

ui/sdl2.c

@@ -817,7 +817,10 @@ static void sdl2_display_init(DisplayState *ds, DisplayOptions *o)
      * This is a bit hackish but saves us from bigger problem.
      * Maybe it's a good idea to fix this in SDL instead.
      */
-    g_setenv("SDL_VIDEODRIVER", "x11", 0);
+    if (!g_setenv("SDL_VIDEODRIVER", "x11", 0)) {
+        fprintf(stderr, "Could not set SDL_VIDEODRIVER environment variable\n");
+        exit(1);
+    }
 #endif
 
     if (SDL_Init(SDL_INIT_VIDEO)) {