Index: /trunk/src/VBox/ValidationKit/tests/additions/tdAddGuestCtrl.py
===================================================================
--- /trunk/src/VBox/ValidationKit/tests/additions/tdAddGuestCtrl.py	(revision 84243)
+++ /trunk/src/VBox/ValidationKit/tests/additions/tdAddGuestCtrl.py	(revision 84244)
@@ -2994,4 +2994,23 @@
                             tdTestResultExec(fRc = True) ]);
 
+        # Test very long arguments.
+        if self.oTstDrv.fpApiVer >= 6.1:
+            if oTestVm.isWindows() \
+            or oTestVm.isOS2():
+                sEcho = sShell;
+            else:
+                sEcho       = "/bin/echo";
+                # The suffix acts as an indicator / beacon to see if the actual (random) args were received fully.
+                sEchoSuffix = "-n";
+
+            for _ in xrange(0, 16):
+                ## @todo Check limits; on Ubuntu with 256KB IPRT returns VERR_NOT_IMPLEMENTED.
+                atExec.append([ tdTestExec(sCmd = sEcho,
+                                           asArgs = [ sEcho, sShellOpt,
+                                                      self.oTestFiles.generateFilenameEx(128 * 1024, 2048), sEchoSuffix ],
+                                           afFlags = [ vboxcon.ProcessCreateFlag_WaitForStdOut,
+                                                       vboxcon.ProcessCreateFlag_WaitForStdErr ]),
+                                tdTestResultExec(fRc = True) ]);
+
         # Build up the final test array for the first batch.
         atTests = atInvalid + atExec;