bug#35596: view-lossage should leave less blank lines at bottom

bug#35596: view-lossage should leave less blank lines at bottom

[積丹尼 Dan Jacobson]

   C-h l runs the command view-lossage (found in global-map), which is an
   interactive compiled Lisp function in ‘help.el’.

   It is bound to C-h l, <f1> l, <help> l.

Well it doesn't seem so smart. Every time I use it the bottom half of
its window is wasted. Wouldn't it be smarter to just leave one or zero
blank lines at bottom?

bug#35596: view-lossage should leave less blank lines at bottom

[Juri Linkov]

>    C-h l runs the command view-lossage (found in global-map), which is an
>    interactive compiled Lisp function in ‘help.el’.
>
>    It is bound to C-h l, <f1> l, <help> l.
>
> Well it doesn't seem so smart. Every time I use it the bottom half of
> its window is wasted. Wouldn't it be smarter to just leave one or zero
> blank lines at bottom?

The last line of 'view-lossage' has this comment:

      ;; jidanni wants to see the last keystrokes immediately.
      (set-marker help-window-point-marker (point)))))

Why it fails to do what you want?

bug#35596: view-lossage should leave less blank lines at bottom

[積丹尼 Dan Jacobson]

JL> Why it fails to do what you want?

All I know is hold down some key for a long time, then do C-h l. You
will see

-UUU:**--F1  *scratch*      All L4     (Lisp
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 j [self-insert-command]
 C-h l [view-lossage]

[back]
<WASTED BLANK LINE>
<WASTED BLANK LINE>
<WASTED BLANK LINE>
<WASTED BLANK LINE>
<WASTED BLANK LINE>
<WASTED BLANK LINE>
<WASTED BLANK LINE>
-UUU:%%--F1  *Help*         Bot L76    (Help) --

emacs-version "26.1"

bug#35596: view-lossage should leave less blank lines at bottom

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson
> 	<jidanni@jidanni.org>
> Date: Wed, 08 May 2019 05:45:24 +0800
> Cc: 35596@debbugs.gnu.org
> 
> All I know is hold down some key for a long time, then do C-h l. You
> will see
> 
> -UUU:**--F1  *scratch*      All L4     (Lisp
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  j [self-insert-command]
>  C-h l [view-lossage]
> 
> [back]
> <WASTED BLANK LINE>
> <WASTED BLANK LINE>
> <WASTED BLANK LINE>
> <WASTED BLANK LINE>
> <WASTED BLANK LINE>
> <WASTED BLANK LINE>
> <WASTED BLANK LINE>
> -UUU:%%--F1  *Help*         Bot L76    (Help) --
> 
> emacs-version "26.1"

This is the standard Emacs recentering behavior.  If you don't like
it, set scroll-conservatively to a value larger than 100.

bug#35596: view-lossage should leave less blank lines at bottom

[積丹尼 Dan Jacobson]

>>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
EZ> This is the standard Emacs recentering behavior.  If you don't like
EZ> it, set scroll-conservatively to a value larger than 100.

OK, but now
"
[back]"
are cut off form view at the bottom.

bug#35596: view-lossage should leave less blank lines at bottom

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
> Cc: juri@linkov.net,  35596@debbugs.gnu.org
> Date: Wed, 08 May 2019 14:42:42 +0800
> 
> >>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
> EZ> This is the standard Emacs recentering behavior.  If you don't like
> EZ> it, set scroll-conservatively to a value larger than 100.
> 
> OK, but now
> "
> [back]"
> are cut off form view at the bottom.

And that is a problem because...?

That button "wastes useful screen estate", doesn't it?  It's more
important to see one or two more keystrokes that to see this button,
which is always there, right?

bug#35596: view-lossage should leave less blank lines at bottom

[積丹尼 Dan Jacobson]

>>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:

EZ> That button "wastes useful screen estate", doesn't it?  It's more
EZ> important to see one or two more keystrokes that to see this button,
EZ> which is always there, right?

Using your fix on my example nine lines were gained, but two were lost.
I just want to gain seven lines, not nine.

bug#35596: view-lossage should leave less blank lines at bottom

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
> Cc: juri@linkov.net,  35596@debbugs.gnu.org
> Date: Wed, 08 May 2019 15:21:51 +0800
> 
> >>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
> 
> EZ> That button "wastes useful screen estate", doesn't it?  It's more
> EZ> important to see one or two more keystrokes that to see this button,
> EZ> which is always there, right?
> 
> Using your fix on my example nine lines were gained, but two were lost.
> I just want to gain seven lines, not nine.

Then the "jidanni wants" code should be modified to put point at EOB,
that's all.  That code currently does what you requested earlier, and
now you don't like the result.

bug#35596: view-lossage should leave less blank lines at bottom

[積丹尼 Dan Jacobson]

>>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
EZ> Then the "jidanni wants" code should be modified to put point at EOB,
EZ> that's all.  That code currently does what you requested earlier, and
EZ> now you don't like the result.

I bet back then they hadn't added the "\n[back]\n" yet anyway.

bug#35596: view-lossage should leave less blank lines at bottom

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
> Cc: juri@linkov.net,  35596@debbugs.gnu.org
> Date: Wed, 08 May 2019 16:05:29 +0800
> 
> >>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
> EZ> Then the "jidanni wants" code should be modified to put point at EOB,
> EZ> that's all.  That code currently does what you requested earlier, and
> EZ> now you don't like the result.
> 
> I bet back then they hadn't added the "\n[back]\n" yet anyway.

Look at the code.  The code explicitly sets point to the end of the
text produced by the Help command, whereas the button is added after
that text.

bug#35596: view-lossage should leave less blank lines at bottom

[積丹尼 Dan Jacobson]

All I know is I am using emacs 26.1.
The first C-h l "wastes" half the *Help* buffer with blank lines.
Upon a second C-h l, the "\n[back]" appears, but still there is plenty
of wasteful blank lines below it.

I think there shouldn't be any blank lines following the "\n[back]",
unless we just started emacs and there isn't much to report.

I think this should be the default behavior and users shouldn't need to
set some variable (that is not even mentioned on C-h k C-h l) to "some
value over 100" to achieve it.

bug#35596: view-lossage should leave less blank lines at bottom

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
> Cc: juri@linkov.net,  35596@debbugs.gnu.org
> Date: Wed, 08 May 2019 19:46:56 +0800
> 
> I think there shouldn't be any blank lines following the "\n[back]",
> unless we just started emacs and there isn't much to report.
> 
> I think this should be the default behavior and users shouldn't need to
> set some variable (that is not even mentioned on C-h k C-h l) to "some
> value over 100" to achieve it.

And I think there's nothing wrong with the default behavior as it is.
Emacs behaves like that with any window that pops up to show any
content.

bug#35596: view-lossage should leave less blank lines at bottom

[積丹尼 Dan Jacobson]

Well then take my name out of that code comment. As whatever change they
made doesn't still work in 26.1.

bug#35596: view-lossage should leave less blank lines at bottom

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
> Cc: juri@linkov.net,  35596-done@debbugs.gnu.org
> Date: Wed, 08 May 2019 20:45:19 +0800
> 
> Well then take my name out of that code comment. As whatever change they
> made doesn't still work in 26.1.

It wasn't a change: we always showed point after the last command in
the history.  I changed the comment accordingly.