[gdb/testsuite] Make ^C cancel i-searchHEADmaster

PR cli/21690 reports the following: say we start gdb:
...
$ gdb -q
(gdb)
...
and press ^R for reverse-i-search:
...
(reverse-i-search)`':
...

Pressing the p key has the effect of showing both the pressed key and a
matching entry, which happens to be up:
...
(reverse-i-search)`p': up
...

Now we press ^C to cancel the search:
...
(reverse-i-search)`p': u❌️ Quit
(gdb)
...
and type "down".

We expected to get:
...
(gdb) down
...
but instead we get:
...
(failed reverse-i-search)`pdown':
...

So we're stuck in reverse-i-search, until we use the workaround of ^G.

The same problem happened with python [1], was reported upstream [2], and
fixed in cpython commit d6990d221b0 ("Issue #24266: Cancel history search mode
with Ctrl+C in Readline 7") using rl_callback_sigcleanup.

Fix this likewise in quit using rl_callback_sigcleanup, a new callback
function in readline 7.0:
...
i.  rl_callback_sigcleanup: a new application function that can clean up and
    unset any state set by readline's callback mode.  Intended to be used
    after a signal.
...
giving us instead:
...
$ gdb
(gdb) u❌️ Quit
(gdb) down
...

Remove the corresponding kfail in gdb.tui/pr30056.exp.

Tested on x86_64-linux.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=21690

[1] https://bugs.python.org/issue24266
[2] https://lists.gnu.org/archive/html/bug-readline/2015-05/msg00014.html

0 files changed, 0 insertions, 0 deletions