improved rubbing out commands with modifiers

* This was actually broken if the command is preceded by `@` and `:` characters, which
  are __not__ modifiers.
  E.g. `Q:@I/foo^W` would have rubbed out the `:` register as well.
* Also, since it was all done in teco_state_process_edit_cmd(),
  it would also rub out modifier characters from within string arguments,
  E.g. `@I/::^EQ^W`
* Real commands now have their own ^W rubout implementation, while the generic
  fallback just rubs out until the start state is re-established.
  This fails to rub out modifiers as in `@I/^W`, though.
* Real command characters now use the common TECO_DEFINE_STATE_COMMAND().
* Added test cases for CTRL+W rub out.
  A few control characters are now portably available to tests
  via environment variables `$ESCAPE`, `$RUBOUT` and `$RUBOUT_WORD`.

1 files changed, 2 insertions, 0 deletions

diff --git a/doc/sciteco.7.template b/doc/sciteco.7.template
index d5fc4af..1fe1dba 100644
--- a/doc/sciteco.7.template
+++ b/doc/sciteco.7.template
@@ -518,6 +518,8 @@ Miscelleaneous
 .br
 (modifier \fIdisabled\fP)
 T};T{
+\# Strictly speaking, it only does that from the start state.
+\# At the beginning of strings or Q-reg specs, it only erases until the start state.
 Rub out until the beginning of the last command, which is not a no-op (whitespace).
 \(lq@\(rq and \(lq:\(rq modifiers are considered part of the command and also rubbed out.
 T}