* Removed fbu-requests from the places I missed earlier.

* Added a few clarifying comments.

include/rfb.js

@@ -595,7 +595,6 @@ mouseButton = function(x, y, down, bmask) {
             return;
         } else {
             viewportDragging = false;
-            ws.send(fbUpdateRequests()); // Force immediate redraw
         }
     }
 
@@ -873,7 +872,7 @@ init_msg = function() {
 
         response = pixelFormat();
         response = response.concat(clientEncodings());
-        response = response.concat(fbUpdateRequests());
+        response = response.concat(fbUpdateRequests()); // initial fbu-request
         timing.fbu_rt_start = (new Date()).getTime();
         timing.pixels = 0;
         ws.send(response);
@@ -907,6 +906,7 @@ normal_msg = function() {
     case 0:  // FramebufferUpdate
         ret = framebufferUpdate(); // false means need more data
         if (ret) {
+            // only allow one outstanding fbu-request at a time
             ws.send(fbUpdateRequests());
         }
         break;
@@ -1571,8 +1571,6 @@ encHandlers.DesktopSize = function set_desktopsize() {
     conf.onFBResize(that, fb_width, fb_height);
     display.resize(fb_width, fb_height);
     timing.fbu_rt_start = (new Date()).getTime();
-    // Send a new non-incremental request
-    ws.send(fbUpdateRequests());
 
     FBU.bytes = 0;
     FBU.rects -= 1;
@@ -1798,7 +1796,6 @@ that.sendCtrlAltDel = function() {
     arr = arr.concat(keyEvent(0xFFFF, 0)); // Delete
     arr = arr.concat(keyEvent(0xFFE9, 0)); // Alt
     arr = arr.concat(keyEvent(0xFFE3, 0)); // Control
-    arr = arr.concat(fbUpdateRequests());
     ws.send(arr);
 };
 
@@ -1815,7 +1812,6 @@ that.sendKey = function(code, down) {
         arr = arr.concat(keyEvent(code, 1));
         arr = arr.concat(keyEvent(code, 0));
     }
-    arr = arr.concat(fbUpdateRequests());
     ws.send(arr);
 };