Refactor 'SelfInsert' to avoid duplicate logic (#1510)

Author: daxian-dbw

PSReadLine/BasicEditing.cs

@@ -31,26 +31,20 @@ public static void SelfInsert(ConsoleKeyInfo? key = null, object arg = null)
             {
                 if (count <= 0)
                     return;
-                if (count > 1)
-                {
-                    var toInsert = new string(keyChar, count);
-                    if (_singleton._visualSelectionCommandCount > 0)
-                    {
-                        _singleton.GetRegion(out var start, out var length);
-                        Replace(start, length, toInsert);
-                    }
-                    else
-                    {
-                        Insert(toInsert);
-                    }
-                    return;
-                }
+            }
+            else
+            {
+                count = 1;
             }
 
             if (_singleton._visualSelectionCommandCount > 0)
             {
                 _singleton.GetRegion(out var start, out var length);
-                Replace(start, length, new string(keyChar, 1));
+                Replace(start, length, new string(keyChar, count));
+            }
+            else if (count > 1)
+            {
+                Insert(new string(keyChar, count));
             }
             else
             {