BUG: You may receive a StackOverflowException exception when you make a child MDI form visible in Visual Studio .NET 2003 and in Visual Studio .NET 2002 (893710)

MORE INFORMATION

Steps to reproduce the problem

1. Start Visual Studio .NET.
2. Create a new Microsoft Windows application that is named Q893710.
3. In Solution Explorer, right-click the application, point to Add, and then click Add Windows Form.
4. Name the new form parentForm.
5. In Solution Explorer, right-click the application, point to Add, and then click Add Windows Form.
6. Name the new form childForm.
7. Right-click Form1, and then click View code.
8. Replace all the code in Form1 with the following lines of code.

   using System;
   using System.Drawing;
   using System.Collections;
   using System.ComponentModel;
   using System.Windows.Forms;
   
   namespace Q893710
   {
   	/// <summary>
   	/// Summary description for Form1.
   	/// </summary>
   	public class Form1 : System.Windows.Forms.Form
   	{
   		private parentForm pForm;
   		private childForm cForm;
   		private System.Windows.Forms.Button btnOverflow;
   		private System.Windows.Forms.Button btnCreateForms;
   		private System.Windows.Forms.Button btnCheckVisible;
   
   		/// <summary>
   		/// Required designer variable.
   		/// </summary>
   		private System.ComponentModel.Container components = null;
   
   		public Form1()
   		{
   			InitializeComponent();
   		}
   
   		protected override void Dispose( bool disposing )
   		{
   			if( disposing )
   			{
   				if(components != null)
   				{
   					components.Dispose();
   				}
   			}
   			base.Dispose( disposing );
   		}
   
   			private void InitializeComponent()
   		{
   			this.btnCreateForms = new System.Windows.Forms.Button();
   			this.btnOverflow = new System.Windows.Forms.Button();
   			this.btnCheckVisible = new System.Windows.Forms.Button();
   			this.SuspendLayout();
   			// 
   			// btnCreateForms
   			// 
   			this.btnCreateForms.Location = new System.Drawing.Point(8, 24);
   			this.btnCreateForms.Name = "btnCreateForms";
   			this.btnCreateForms.Size = new System.Drawing.Size(112, 23);
   			this.btnCreateForms.TabIndex = 0;
   			this.btnCreateForms.Text = "1. Create forms";
   			this.btnCreateForms.Click += new System.EventHandler(this.btnCreateForms_Click);
   			// 
   			// btnOverflow
   			// 
   			this.btnOverflow.BackColor = System.Drawing.Color.Red;
   			this.btnOverflow.Location = new System.Drawing.Point(160, 240);
   			this.btnOverflow.Name = "btnOverflow";
   			this.btnOverflow.Size = new System.Drawing.Size(120, 23);
   			this.btnOverflow.TabIndex = 1;
   			this.btnOverflow.Text = "STACK OVERFLOW";
   			this.btnOverflow.Click += new System.EventHandler(this.btnOverflow_Click);
   			// 
   			// btnCheckVisible
   			// 
   			this.btnCheckVisible.Location = new System.Drawing.Point(8, 56);
   			this.btnCheckVisible.Name = "btnCheckVisible";
   			this.btnCheckVisible.Size = new System.Drawing.Size(112, 23);
   			this.btnCheckVisible.TabIndex = 2;
   			this.btnCheckVisible.Text = "2. Check all visible";
   			this.btnCheckVisible.Click += new System.EventHandler(this.btnCheckVisible_Click);
   			// 
   			// Form1
   			// 
   			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
   			this.ClientSize = new System.Drawing.Size(292, 273);
   			this.Controls.Add(this.btnCheckVisible);
   			this.Controls.Add(this.btnOverflow);
   			this.Controls.Add(this.btnCreateForms);
   			this.Name = "Form1";
   			this.Text = "Form1";
   			this.ResumeLayout(false);
   
   		}
   	
   
   
   
   
   		private bool allParentsVisible(Control ctl)
   		{
   			ctl = ctl.Parent;
   			while (ctl != null)
   			{
   				if (!ctl.Visible)
   				{
   					return false;
   				}
   				ctl = ctl.Parent;
   			}
   			return true;
   		}
   
   
   		private void btnOverflow_Click(object sender, System.EventArgs e)
   		{
   			//This is bad. Create a stack overflow.
   			pForm.Visible = false;
   			cForm.Show();
   		}
   
   		private void btnCreateForms_Click(object sender, System.EventArgs e)
   		{
   			pForm		= new parentForm();
   			pForm.IsMdiContainer	= true;
   
   			cForm			= new childForm();
   			cForm.MdiParent			= pForm;
   
   			// Show the parent form.
   			pForm.Show();
   		}
   
   		private void btnCheckVisible_Click(object sender, System.EventArgs e)
   		{
   			pForm.Visible = false;
   
   			// Clearly this will not show the form because the visibility of the parent is false.
   			// However, in a "real world" application you may not know where the parent form's visibility is 
   			// changed.  This is one way to help protect against that.
   			if (allParentsVisible(cForm))
   				cForm.Show();
   
   		}
   
   		static void Main() 
   	        {
   		Application.Run(new Form1());
   	        }         
         }
   }

9. Click Start.
10. In the compiled application, click STACK OVERFLOW. You receive a StackOverflowException exception.