nxcomp/src/Loop.cpp: Support NXTransDialog caption / title being pref…

…ixed with a custom prefix string.

nxcomp/src/Loop.cpp

@@ -14731,7 +14731,19 @@ static void handleAlertInLoop()
     {
       char caption[DEFAULT_STRING_LENGTH];
 
-      strcpy(caption, ALERT_CAPTION_PREFIX);
+      const char* caption_prefix = getenv("NX_DIALOG_CAPTIONPREFIX");
+
+      if (!caption_prefix) {
+          // Use the hard-coded 'NX -' as default.
+          strncpy(caption, ALERT_CAPTION_PREFIX, DEFAULT_STRING_LENGTH);
+          caption[DEFAULT_STRING_LENGTH-1] = '\0';
+      }
+      else
+      {
+          // Use what gets provided via NX_DIALOG_CAPTIONPREFIX (used in X2Go)
+          strncpy(caption, caption_prefix, DEFAULT_STRING_LENGTH-1);
+          caption[DEFAULT_STRING_LENGTH-1] = '\0';
+      }
 
       int length = strlen(sessionId);
 

nxproxy/man/nxproxy.1

@@ -376,6 +376,14 @@ where <nxclient> is located in a different directory compared to the
 other programs, to make easier for the user to execute the program from
 the shell.
 
+.TP 8
+.B  NX_DIALOG_CAPTIONPREFIX
+This variable can be used to override the default caption prefix for
+agent calls to nxdialog. By default (if NX_DIALOG_CAPTIONPREFIX is
+unset), the caption prefix gets set to 'NX - '. This variable is only
+used if the proxy is running in server mode or if nxcomp code is run
+as part of nxagent.
+
 .TP 8
 .B  NX_SLAVE_CMD
 The full path to the slave channel handler. When the slave channel is