fixed rubout of empty forward kill (FK)

Test case:

  IF$ J IX$ FKF$ ^W

The range to delete is empty, Scintilla would not generate an undo action,
but SCI_UNDO would still be exected on rubout which removes the "X" too early.

* We should really get rid of Scintilla undo actions as they are a source of trouble
  and complexity.
  There could be a custom undo token to undo SCI_DELETERANGE that automatically
  fetches the text that's going to be deleted and stores it in the token's data.
  This could replace most uses of SCI_UNDO.
  The rest is to undo insertions, which can easily be replaced with
  undo__teco_interface_ssm(SCI_DELETERANGE...).
* We should really allow rubout tests in the test suite...

0 files changed, 0 insertions, 0 deletions