[PATCH 2 of 2] pager: skip running the pager if it's set to 'cat'

[Ryan McElroy]

On 3/15/17 6:44 PM, Augie Fackler wrote:
> # HG changeset patch
> # User Augie Fackler <augie at google.com>
> # Date 1489624466 14400
> #      Wed Mar 15 20:34:26 2017 -0400
> # Node ID bc0c38ec3f7be807607d4fdf871f344e7079d992
> # Parent  07d488f16da6e12b225d2827f1020f32c8050a7a
> pager: skip running the pager if it's set to 'cat'
>
> Avoid useless uses of cat.

I hate myself a little for being this pedantic... but if 'cat' means 
something else in a users environment (eg, alias cat="cat -v"), then 
this would break that behavior.

>
> diff --git a/mercurial/ui.py b/mercurial/ui.py
> --- a/mercurial/ui.py
> +++ b/mercurial/ui.py
> @@ -935,6 +935,9 @@ class ui(object):
>           This is separate in part so that extensions (like chg) can
>           override how a pager is invoked.
>           """
> +        if command == 'cat':
> +            # Save ourselves some work.
> +            return
>           # If the command doesn't contain any of these characters, we
>           # assume it's a binary and exec it directly. This means for
>           # simple pager command configurations, we can degrade
>