From d994c8a2f9b764b7bee21affe1b2899e5bbf8514 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mjumper@apache.org>
Date: Sun, 8 Sep 2024 18:12:15 -0700
Subject: [PATCH] GUACAMOLE-377: Restore heuristic detection of VNC frame
 boundaries.

---
 src/protocols/vnc/client.h  |  2 +-
 src/protocols/vnc/display.c |  9 ---------
 src/protocols/vnc/display.h | 11 -----------
 src/protocols/vnc/vnc.c     | 23 +++++++++++++++--------
 4 files changed, 16 insertions(+), 29 deletions(-)

diff --git a/src/protocols/vnc/client.h b/src/protocols/vnc/client.h
index eec4bfce4..37e3d8c55 100644
--- a/src/protocols/vnc/client.h
+++ b/src/protocols/vnc/client.h
@@ -32,7 +32,7 @@
  * milliseconds. If the server is silent for at least this amount of time, the
  * frame will be considered finished.
  */
-#define GUAC_VNC_FRAME_TIMEOUT 0
+#define GUAC_VNC_FRAME_TIMEOUT 16
 
 /**
  * The amount of time to wait for a new message from the VNC server when
diff --git a/src/protocols/vnc/display.c b/src/protocols/vnc/display.c
index 93a981b94..f0a670a4e 100644
--- a/src/protocols/vnc/display.c
+++ b/src/protocols/vnc/display.c
@@ -125,15 +125,6 @@ void guac_vnc_update(rfbClient* client, int x, int y, int w, int h) {
 
 }
 
-void guac_vnc_update_finished(rfbClient* client) {
-
-    guac_client* gc = rfbClientGetClientData(client, GUAC_VNC_CLIENT_KEY);
-    guac_vnc_client* vnc_client = (guac_vnc_client*) gc->data;
-
-    guac_display_end_multiple_frames(vnc_client->display, 1);
-
-}
-
 void guac_vnc_copyrect(rfbClient* client, int src_x, int src_y, int w, int h, int dest_x, int dest_y) {
 
     guac_client* gc = rfbClientGetClientData(client, GUAC_VNC_CLIENT_KEY);
diff --git a/src/protocols/vnc/display.h b/src/protocols/vnc/display.h
index fd1bcd04d..cd7d27b25 100644
--- a/src/protocols/vnc/display.h
+++ b/src/protocols/vnc/display.h
@@ -51,17 +51,6 @@
  */
 void guac_vnc_update(rfbClient* client, int x, int y, int w, int h);
 
-/**
- * Callback invoked by libVNCServer when all binary image data for the current
- * frame has been received from the VNC server. The image data that frame will
- * have been exposed via previous calls to guac_vnc_update().
- *
- * @param client
- *     The VNC client associated with the VNC session in which the new image
- *     was received.
- */
-void guac_vnc_update_finished(rfbClient* client);
-
 /**
  * Callback invoked by libVNCServer when it receives a CopyRect message.
  * CopyRect specified a rectangle of source data within the display and a
diff --git a/src/protocols/vnc/vnc.c b/src/protocols/vnc/vnc.c
index 85f0cbf3c..5361b05f9 100644
--- a/src/protocols/vnc/vnc.c
+++ b/src/protocols/vnc/vnc.c
@@ -139,7 +139,6 @@ rfbClient* guac_vnc_get_client(guac_client* client) {
 
     /* Framebuffer update handler */
     rfb_client->GotFrameBufferUpdate = guac_vnc_update;
-    rfb_client->FinishedFrameBufferUpdate = guac_vnc_update_finished;
     rfb_client->GotCopyRect = guac_vnc_copyrect;
 
 #ifdef ENABLE_VNC_TLS_LOCKING
@@ -553,18 +552,26 @@ void* guac_vnc_client_thread(void* data) {
         if (wait_result == 0)
             continue;
 
-        /* Handle any message received */
-        if (!HandleRFBServerMessage(rfb_client)) {
-            guac_client_abort(client,
-                    GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
-                    "Error handling message from VNC server.");
-            break;
-        }
+        do {
+
+            /* Handle any message received */
+            if (!HandleRFBServerMessage(rfb_client)) {
+                guac_client_abort(client,
+                        GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR,
+                        "Error handling message from VNC server.");
+                break;
+            }
+
+            wait_result = guac_vnc_wait_for_messages(rfb_client, GUAC_VNC_FRAME_TIMEOUT);
+
+        } while (wait_result > 0);
 
         /* If an error occurs, log it and fail */
         if (wait_result < 0)
             guac_client_abort(client, GUAC_PROTOCOL_STATUS_UPSTREAM_ERROR, "Connection closed.");
 
+        guac_display_end_frame(vnc_client->display);
+
     }
 
     /* Kill client and finish connection */