[Qemu-devel] [PATCH 1/4] vnc: set the right prefered encoding

[Corentin Chary <corentincj@iksaif.net>]

>From RFB specs: "The order of the encoding types given in this
message is a hint by the client as to its preference (the first
encoding specified being most preferred)"

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
---
 vnc.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/vnc.c b/vnc.c
index b1a3fdb..a91c3a3 100644
--- a/vnc.c
+++ b/vnc.c
@@ -1587,6 +1587,13 @@ static void send_ext_audio_ack(VncState *vs)
     vnc_flush(vs);
 }
 
+static void set_encoding(VncState *vs, int encoding)
+{
+    if (vs->vnc_encoding == -1) {
+        vs->vnc_encoding = encoding;
+    }
+}
+
 static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
 {
     int i;
@@ -1594,7 +1601,7 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
 
     vnc_zlib_init(vs);
     vs->features = 0;
-    vs->vnc_encoding = 0;
+    vs->vnc_encoding = -1;
     vs->tight_compression = 9;
     vs->tight_quality = 9;
     vs->absolute = -1;
@@ -1603,18 +1610,18 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
         enc = encodings[i];
         switch (enc) {
         case VNC_ENCODING_RAW:
-            vs->vnc_encoding = enc;
+            set_encoding(vs, enc);
             break;
         case VNC_ENCODING_COPYRECT:
             vs->features |= VNC_FEATURE_COPYRECT_MASK;
             break;
         case VNC_ENCODING_HEXTILE:
             vs->features |= VNC_FEATURE_HEXTILE_MASK;
-            vs->vnc_encoding = enc;
+            set_encoding(vs, enc);
             break;
         case VNC_ENCODING_ZLIB:
             vs->features |= VNC_FEATURE_ZLIB_MASK;
-            vs->vnc_encoding = enc;
+            set_encoding(vs, enc);
             break;
         case VNC_ENCODING_DESKTOPRESIZE:
             vs->features |= VNC_FEATURE_RESIZE_MASK;
-- 
1.7.0.2