[Bug-readline] [PATCH] Gnuplot on macOS does not suspend by Control-z

[Rin Okuyama]

Hi,

Gnuplot on macOS does not suspend by Control-z in its command line.
Please find the details below and attached patch.

Best regards,
Rin Okuyama
----
* VERSION

7.0 (the latest git source as of 2017-11-21).

* ENVIRONMENT

macOS 10.13.1 (also observed on 10.8.5).

* COMPILATION FLAGS etc.

Default settings generated by configure script.

* DESCRIPTION

Gnuplot 5.2.2 (and maybe all other versions) does not suspend only by
Control-z in its command line. If you type any key after Control-z, it
receives SIGTSTP and suspends.

* RECIPE FOR REPRODUCE

Try to suspend gnuplot on macOS by Control-z key.

* FIX

At the moment, readline does not disable VSUSP, and expect SIGTSTP to
be appropriately sent by the tty driver. However, unfortunately, it
does not work on macOS.

By applying this patch, readline explicitly disables VSUSP, and handles
Control-z by its own.

Applications like bash should not suspend by Control-z. However, this
patch does not take care of such a case.

readline.patch
Description: Text document