GUACAMOLE-1302: Add RDP support for forcing lossless compression.

src/protocols/rdp/rdp.c

@@ -435,6 +435,10 @@ static int guac_rdp_handle_connection(guac_client* client) {
             rdp_client->settings->width,
             rdp_client->settings->height);
 
+    /* Use lossless compression only if requested (otherwise, use default
+     * heuristics) */
+    guac_common_display_set_lossless(rdp_client->display, settings->lossless);
+
     rdp_client->current_surface = rdp_client->display->default_surface;
 
     rdp_client->available_svc = guac_common_list_alloc();

src/protocols/rdp/settings.c

@@ -128,6 +128,8 @@ const char* GUAC_RDP_CLIENT_ARGS[] = {
     "wol-broadcast-addr",
     "wol-udp-port",
     "wol-wait-time",
+
+    "force-lossless",
     NULL
 };
 
@@ -639,6 +641,12 @@ enum RDP_ARGS_IDX {
      */
     IDX_WOL_WAIT_TIME,
 
+    /**
+     * "true" if all graphical updates for this connection should use lossless
+     * compresion only, "false" or blank otherwise.
+     */
+    IDX_FORCE_LOSSLESS,
+
     RDP_ARGS_COUNT
 };
 
@@ -779,6 +787,11 @@ guac_rdp_settings* guac_rdp_parse_args(guac_user* user,
             settings->height,
             settings->resolution);
 
+    /* Lossless compression */
+    settings->lossless =
+        guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,
+                IDX_FORCE_LOSSLESS, 0);
+
     /* Domain */
     settings->domain =
         guac_user_parse_args_string(user, GUAC_RDP_CLIENT_ARGS, argv,

src/protocols/rdp/settings.h

@@ -192,6 +192,12 @@ typedef struct guac_rdp_settings {
      */
     int resolution;
 
+    /**
+     * Whether all graphical updates for this connection should use lossless
+     * compression only.
+     */
+    int lossless;
+
     /**
      * Whether audio is enabled.
      */