Make VNC use the default backend again if one is defined.
The recently introduced support for disabling the VNC audio
extension is still used, in case no default backend exists.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 audio/audio.c                   | 28 ++++++++++++++++++----------
 audio/audio.h                   |  1 +
 docs/about/removed-features.rst |  6 ------
 ui/vnc.c                        |  2 ++
 4 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/audio/audio.c b/audio/audio.c
index bd4bcabccaf..73b65dc3b9b 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1801,20 +1801,28 @@ out:
     return NULL;
 }
 
+AudioState *audio_get_default_audio_state(Error **errp)
+{
+    if (!default_audio_state) {
+        default_audio_state = audio_init(NULL, errp);
+        if (!default_audio_state) {
+            if (!QSIMPLEQ_EMPTY(&audiodevs)) {
+                error_append_hint(errp, "Perhaps you wanted to use -audio or set audiodev=%s?\n",
+                                  QSIMPLEQ_FIRST(&audiodevs)->dev->id);
+            }
+        }
+    }
+
+    return default_audio_state;
+}
+
 bool AUD_register_card (const char *name, QEMUSoundCard *card, Error **errp)
 {
     if (!card->state) {
-        if (!default_audio_state) {
-            default_audio_state = audio_init(NULL, errp);
-            if (!default_audio_state) {
-                if (!QSIMPLEQ_EMPTY(&audiodevs)) {
-                    error_append_hint(errp, "Perhaps you wanted to use -audio or set audiodev=%s?\n",
-                                      QSIMPLEQ_FIRST(&audiodevs)->dev->id);
-                }
-                return false;
-            }
+        card->state = audio_get_default_audio_state(errp);
+        if (!card->state) {
+            return false;
         }
-        card->state = default_audio_state;
     }
 
     card->name = g_strdup (name);
diff --git a/audio/audio.h b/audio/audio.h
index 6da5e8f6f0f..fcc22307bee 100644
--- a/audio/audio.h
+++ b/audio/audio.h
@@ -176,6 +176,7 @@ void audio_init_audiodevs(void);
 void audio_help(void);
 
 AudioState *audio_state_by_name(const char *name, Error **errp);
+AudioState *audio_get_default_audio_state(Error **errp);
 const char *audio_get_id(QEMUSoundCard *card);
 
 #define DEFINE_AUDIO_PROPERTIES(_s, _f)         \
diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst
index ed94b4cd0c8..f04036987b1 100644
--- a/docs/about/removed-features.rst
+++ b/docs/about/removed-features.rst
@@ -460,12 +460,6 @@ in this case.
 Note that the default audio backend must be configured on the command
 line if the ``-nodefaults`` options is used.
 
-Creating vnc without ``audiodev=`` property (removed in 8.2)
-''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
-
-When using vnc, you should specify an ``audiodev=`` property if
-you plan to transmit audio through the VNC protocol.
-
 QEMU Machine Protocol (QMP) commands
 ------------------------------------
 
diff --git a/ui/vnc.c b/ui/vnc.c
index acbb88c4ca0..7f4c471503a 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -4185,6 +4185,8 @@ void vnc_display_open(const char *id, Error **errp)
         if (!vd->audio_state) {
             goto fail;
         }
+    } else {
+        vd->audio_state = audio_get_default_audio_state(NULL);
     }
 
     device_id = qemu_opt_get(opts, "display");
-- 
2.41.0