Remove extra prompt string added to interactive debugging session

This change removes some code that was causing an extra command prompt
string to be printed to the integrated console when running an
interactive debugging session.  It also makes the termination of such a
session more reliable.

Resolves #422.

Author: daviwil

src/PowerShellEditorServices.Protocol/Server/DebugAdapter.cs

@@ -26,14 +26,15 @@ public class DebugAdapter : DebugAdapterBase
         private OutputDebouncer outputDebouncer;
 
         private bool noDebug;
+        private string arguments;
         private bool isRemoteAttach;
         private bool isAttachSession;
         private bool waitingForAttach;
         private string scriptToLaunch;
         private bool enableConsoleRepl;
         private bool ownsEditorSession;
         private bool executionCompleted;
-        private string arguments;
+        private bool isInteractiveDebugSession;
         private RequestContext<object> disconnectRequestContext = null;
 
         public DebugAdapter(HostDetails hostDetails, ProfilePaths profilePaths)
@@ -303,13 +304,9 @@ protected async Task HandleLaunchRequest(
 
             await requestContext.SendResult(null);
 
-            // If no script is being launched, execute an empty script to
-            // cause the prompt string to be evaluated and displayed
-            if (string.IsNullOrEmpty(this.scriptToLaunch))
-            {
-                await this.editorSession.PowerShellContext.ExecuteScriptString(
-                    "", false, true);
-            }
+            // If no script is being launched, mark this as an interactive
+            // debugging session
+            this.isInteractiveDebugSession = string.IsNullOrEmpty(this.scriptToLaunch);
 
             if (this.editorSession.ConsoleService.EnableConsoleRepl)
             {
@@ -447,6 +444,11 @@ protected async Task HandleDisconnectRequest(
                 {
                     this.disconnectRequestContext = requestContext;
                     this.editorSession.PowerShellContext.AbortExecution();
+
+                    if (this.isInteractiveDebugSession)
+                    {
+                        await this.OnExecutionCompleted(null);
+                    }
                 }
                 else
                 {