added error message when attempting to view kernel thread stacks

git-svn-id: svn://svn.code.sf.net/p/processhacker/code@1095 21ef857c-d57f-4fe0-8362-d861dc6d29cd

trunk/ProcessHacker/Components/ThreadList.cs

@@ -477,7 +477,16 @@ namespace ProcessHacker.Components
 
         private void inspectThreadMenuItem_Click(object sender, EventArgs e)
         {
-            if (_pid == Process.GetCurrentProcess().Id)
+            if (_pid == 4)
+            {
+                MessageBox.Show(
+                    "Process Hacker does not currently support viewing kernel call stacks.",
+                    "Process Hacker", MessageBoxButtons.OK, MessageBoxIcon.Error);
+
+                return;
+            }
+
+            if (_pid == Win32.GetCurrentProcessId())
             {
                 if (MessageBox.Show(
                     "Inspecting Process Hacker's threads will lead to instability. Are you sure you want to continue?",