[PATCH] Preserve "set height 0" when resizing terminal

[PATCH] Preserve "set height 0" when resizing terminal

[Tom Tromey]

PR cli/26650 points out that if "set height 0" is specified, then it
is forgotten on SIGWINCH.  This patch arranges to preserve this
setting (but not other values of "set height").

gdb/ChangeLog
2020-09-23  Tom Tromey  <tromey@adacore.com>

	PR cli/26650:
	* utils.c (set_screen_width_and_height): Preserve "set height 0".
---
 gdb/ChangeLog | 5 +++++
 gdb/utils.c   | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/gdb/utils.c b/gdb/utils.c
index fb1308ac9ae..2e8b2a5bdc9 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -1378,11 +1378,18 @@ set_height_command (const char *args, int from_tty, struct cmd_list_element *c)
 void
 set_screen_width_and_height (int width, int height)
 {
+  /* If the user did "set height 0", make sure to preserve it after
+     handling the height change.  */
+  unsigned int saved_lines = lines_per_page;
+
   lines_per_page = height;
   chars_per_line = width;
 
   set_screen_size ();
   set_width ();
+
+  if (saved_lines == UINT_MAX)
+    lines_per_page = UINT_MAX;
 }
 
 /* The currently applied style.  */
-- 
2.26.2

Re: [PATCH] Preserve "set height 0" when resizing terminal

[Simon Marchi]

On 2020-09-23 3:39 p.m., Tom Tromey wrote:
> PR cli/26650 points out that if "set height 0" is specified, then it
> is forgotten on SIGWINCH.  This patch arranges to preserve this
> setting (but not other values of "set height").
>
> gdb/ChangeLog
> 2020-09-23  Tom Tromey  <tromey@adacore.com>
>
> 	PR cli/26650:
> 	* utils.c (set_screen_width_and_height): Preserve "set height 0".

This LGTM.

Simon

Re: [PATCH] Preserve "set height 0" when resizing terminal

[Andrew Burgess]

* Tom Tromey <tromey@adacore.com> [2020-09-23 13:39:45 -0600]:

> PR cli/26650 points out that if "set height 0" is specified, then it
> is forgotten on SIGWINCH.  This patch arranges to preserve this
> setting (but not other values of "set height").
> 
> gdb/ChangeLog
> 2020-09-23  Tom Tromey  <tromey@adacore.com>
> 
> 	PR cli/26650:
> 	* utils.c (set_screen_width_and_height): Preserve "set height 0".
> ---
>  gdb/ChangeLog | 5 +++++
>  gdb/utils.c   | 7 +++++++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/gdb/utils.c b/gdb/utils.c
> index fb1308ac9ae..2e8b2a5bdc9 100644
> --- a/gdb/utils.c
> +++ b/gdb/utils.c
> @@ -1378,11 +1378,18 @@ set_height_command (const char *args, int from_tty, struct cmd_list_element *c)
>  void
>  set_screen_width_and_height (int width, int height)
>  {
> +  /* If the user did "set height 0", make sure to preserve it after
> +     handling the height change.  */
> +  unsigned int saved_lines = lines_per_page;
> +
>    lines_per_page = height;
>    chars_per_line = width;
>  
>    set_screen_size ();
>    set_width ();
> +
> +  if (saved_lines == UINT_MAX)
> +    lines_per_page = UINT_MAX;
>  }

What if the user does `set height 10` does that not deserve to be
preserved?  What about `set width 0` should that not be preserved?  Or
`set width 60`?

It almost feels like for both height and width we should track if the
value is the default, or user specified.

The we should allow `set height auto` and `set width auto`...

We might want/need something like that anyway to allow the user to get
back from `set height 0` to something sane without having to just guess
- previously they could just resize the window and boom they had the
height set to the "default", but now a user has to play guess the
window height...

Either way we should probably decide what we support and don't support
and document it I think.

Thanks,
Andrew