No need to clear lines when it's not a menu completion rendering (#3199)

Author: daxian-dbw

PSReadLine/Completion.cs

@@ -506,26 +506,26 @@ public void DrawMenu(Menu previousMenu, bool menuSelect)
                     }
                 }
 
-                // if the menu has moved, we need to clear the lines under it
-                if (Top < PreviousTop)
+                if (menuSelect)
                 {
-                    // In either of the following two cases, we will need to move the cursor to the next line:
-                    //  - if extra rows from previous menu were cleared, then we know the current line was erased
-                    //    but the cursor was not moved to the next line.
-                    //  - if 'CursorLeft != 0', then the rest of the last menu row was erased, but the cursor
-                    //    was not moved to the next line.
-                    if (extraPreRowsCleared || console.CursorLeft != 0)
+                    // if the menu has moved, we need to clear the lines under it
+                    if (Top < PreviousTop)
                     {
-                        // There are lines from the previous rendering that need to be cleared,
-                        // so we are sure there is no need to scroll.
-                        MoveCursorDown(1);
-                    }
+                        // In either of the following two cases, we will need to move the cursor to the next line:
+                        //  - if extra rows from previous menu were cleared, then we know the current line was erased
+                        //    but the cursor was not moved to the next line.
+                        //  - if 'CursorLeft != 0', then the rest of the last menu row was erased, but the cursor
+                        //    was not moved to the next line.
+                        if (extraPreRowsCleared || console.CursorLeft != 0)
+                        {
+                            // There are lines from the previous rendering that need to be cleared,
+                            // so we are sure there is no need to scroll.
+                            MoveCursorDown(1);
+                        }
 
-                    Singleton.WriteBlankLines(PreviousTop - Top);
-                }
+                        Singleton.WriteBlankLines(PreviousTop - Top);
+                    }
 
-                if (menuSelect)
-                {
                     RestoreCursor();
                     console.CursorVisible = true;
                 }