Handle the deleting of a step marked for copy

PROMS/Volian.Controls.Library/StepTabRibbon.cs

@@ -645,6 +645,7 @@ namespace Volian.Controls.Library
 				btnCMGoTo.Enabled = btnGoTo.Enabled = true;
 			else
 			{
+				if (_MyStepRTB == null) return;
 				if (_MyStepRTB.IsSelectionLinked(_MyStepRTB.SelectionStart, _MyStepRTB.SelectionLength))
 				{
 					// if selected text = ?, i.e. a missing/undefined destination, don't allow go to
@@ -1810,6 +1811,15 @@ namespace Volian.Controls.Library
 
 		public void btnDelStep_Click(object sender, EventArgs e)
 		{
+			bool clearCopyStep = false;
+			StepTabPanel tmp = Parent as StepTabPanel;
+			if (tmp.MyDisplayTabControl.MyCopyStep != null &&
+				tmp.MyDisplayTabControl.MyCopyStep.ItemID == MyEditItem.MyItemInfo.ItemID)
+			{
+				if (MessageBox.Show("Are you sure?\n\nIf you delete this step you will not able to paste it.\nYou should paste it before you delete it.", "Attempting to delete copied step.", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.No) return;
+				clearCopyStep = true;
+			}
+
 			bool surpressMessageBox = (e == null);
 			SectionInfo si = MyEditItem.MyItemInfo as SectionInfo;
 			if (si != null)
@@ -1836,7 +1846,7 @@ namespace Volian.Controls.Library
 			StepInfo stpi = MyEditItem.MyItemInfo as StepInfo;
 			if (stpi == null)   // not sure that it will every get here!
 			{
-				MessageBox.Show("Unknown type {0}, cannot delete!",MyEditItem.MyItemInfo.GetType().Name);
+				MessageBox.Show("Unknown type {0}, cannot delete!", MyEditItem.MyItemInfo.GetType().Name);
 				return;
 			}
 			if (!surpressMessageBox)
@@ -1858,10 +1868,24 @@ namespace Volian.Controls.Library
 				}
 				MyEditItem.IdentifyChildren(false);
 				if (results == DialogResult.Yes)
+				{
 					MyEditItem.RemoveItem();
+					if (clearCopyStep)
+					{
+						tmp.MyDisplayTabControl.MyCopyStep = null;
+						SetPasteButtonEnabled();
+					}
+				}
 			}
 			else
+			{
 				MyEditItem.RemoveItem();
+				if (clearCopyStep)
+				{
+					tmp.MyDisplayTabControl.MyCopyStep = null;
+					SetPasteButtonEnabled();
+				}
+			}
 		}
 
 		private void btnCMIns_PopupClose(object sender, EventArgs e)