[pkg-lynx-maint] Bug#888391: lynx: RUBOUT deletes character in FRONT of the cursor instead of BEHIND

[Axel Beckert]

Hi Thomas,

thanks for digging into this. It seems to me that this is partially
caused by different expectations and partially by not being aware,
which Lynx settings change the mentioned behaviour.

Thomas Dickey wrote:
> On Thu, Jan 25, 2018 at 03:04:51PM +0100, Axel Beckert wrote:
> > > > I've tested all lynx versions available in supported Debian releases
> > > > and found that those lynx versions in
> > > >
> > > > * Debian Unstable/Buster (2.8.9dev16-2),
> > > > * Debian 9 Stretch (2.8.9dev11-1), and
> > > > * Debian 8 Jessie (2.8.9dev1-2)
> > > >
> > > > exhibit this behaviour, but not the lynx version in
> > > >
> > > > * Debian 7 Wheezy (2.8.8dev.12-2).

Given your hints what might be relevant, namely the "Line edit style"
setting, I must admit that this setting has been different on the
Debian 7 box I used for testing. There I had "Bash-like Bindings".
Otherwise I had "Default Bindings". Which according to the table below
explains very well, why I had a different result there. And changing
it to "Bash-like Bindings" changes my Debian 7 box to exhibit the same
behaviour as the others.

> > > And as mentioned in (an older, hasn't been updated for years) OpenBSD .
> 
> hmm - I have VMs for Debian 5-9 (and some others), but checking
> Debian 6-9, I don't see the behavior described.
[...]
> Here's some data noted while editing text-fields in the options menu:
>
> Debian	Lynx		Keyboard	Backspace	Delete		Del
> 
> 6	2.8.8dev.5-1	bash		DELP		DELN		none
> 6	2.8.8dev.5-1	alternate	DELP		DELP		none
> 6	2.8.8dev.5-1	default		DELP		DELP		none
> 
> 7	2.8.8dev.12-2+deb7u2 bash	DELP		DELN		none
> 7	2.8.8dev.12-2+deb7u2 alternate	DELP		DELP		none
> 7	2.8.8dev.12-2+deb7u2 default	DELP		DELP		none
> 
> 8	2.8.9dev1-2+deb8u1 bash		DELP		DELN		none
> 8	2.8.9dev1-2+deb8u1 alternate	DELP		DELP		none
> 8	2.8.9dev1-2+deb8u1 default	DELP		DELP		none
> 
> 9	2.8.9dev11-1	bash		DELP		DELN		none
> 9	2.8.9dev11-1	alternate	DELP		DELP		none
> 9	2.8.9dev11-1	default		DELP		DELP		none
>
> referring to the section in lynx.cfg discussing keymap:
> #  DELN		# Delete next/curr char
> #  DELP		# Delete prev      char

Which means for me that all Lynx versions in Debian 6 to 9 with "Line
edit-style" (I assume that's meant with "keyboard") set to anything
else than "Bash-like Bindings" exhibit the reported, but unexpected
behaviour of "Delete" deleting the previous character (DELP) instead
of the next/current one (DELN).

As I understood the original reporter, he expects that Delete always
does DELN and never does DELP. And I actually expect this behaviour,
too, hence the "confirmed" tag.
 
> in xterm (the names correspond to a DEC VT220).  In Linux console, that
> "Del" sends the same escape sequence as "Delete".
[...]
> If I've overlooked some detail, steps-to-reproduce would be helpful.

JFTR: How I tested:

* My Lynx has "Line edit style" set to "Default Bindings" (except on
  the one box as mentioned above).
* Took an uxterm.
* I called "lynx https://duckduckgo.com/lite", navigated to the search
  box, typed a few characters, then pressed the cursor left key a few
  times and pressed "Delete" to see which character will be deleted.
* Second test was doing the same, but in the Editor text field of the
  options. No difference here.
* In case of remote boxes (all but Debian Unstable) I used "ssh -t
  lynx ..." inside the uxterm on Debian Unstable.

Hope this helps to clarify where an issue is seen and under which
circumstances it shows up.

		Regards, Axel
-- 
 ,''`.  |  Axel Beckert <abe at debian.org>, https://people.debian.org/~abe/
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