Re: [PATCH 2/2] add-patch: render hunks through the pager

> Make the print command trigger the pager when invoked using a capital
> 'P', to make it easier for the user to review long hunks.
>
> Note that if the PAGER ends unexpectedly before we've been able to send
> the payload, perhaps because the user is not interested in the whole
> thing, we might receive a SIGPIPE, which would abruptly and unexpectedly
> terminate the interactive session for the user.
>
> Therefore, we need to ignore a possible SIGPIPE signal.  Add a test for
> this, in addition to the test for normal operation.
>
> For the SIGPIPE test, we need to make sure that we completely fill the
> operating system's buffer, otherwise we might not trigger the SIGPIPE
> signal.  The normal size of this buffer in different OSs varies from a
> few KBs to 1MB.  Use a payload large enough to guarantee that we exceed
> this limit.

> For the tests, avoid the common construct to set and export one-shot
> variables within the scope of a command:
>
>     VAR=VAL command args
>
> It happens that when "command" is a shell function that in turn executes
> a "command", the behavior with "VAR" varies depending on the shell:
>
>  ** Bash 5.2.21 **
>
>     $ f () { bash -c 'echo A=$A'; }
>     $ A=1 f
>     A=1
>
>  ** dash 0.5.12-9 **
>
>     $ f () { bash -c 'echo A=$A'; }
>     $ A=1 f
>     A=1
>
>  ** dash 0.5.10.2-6 **
>
>     $ f () { bash -c 'echo A=$A'; }
>     $ A=1 f
>     A=
>
> POSIX explicitly says the effect of this construct is unspecified.