Add basic TAP tests for psql's tab-completion logic.

Up to now, psql's tab-complete.c has had exactly no regression test
coverage.  This patch is an experimental attempt to add some.

This needs Perl's IO::Pty module, which isn't installed everywhere,
so the test script just skips all tests if that's not present.
There may be other portability gotchas too, so I await buildfarm
results with interest.

So far this just covers a few very basic keyword-completion and
query-driven-completion scenarios, which should be enough to let us
get a feel for whether this is practical at all from a portability
standpoint.  If it is, there's lots more that can be done.

Discussion: https://postgr.es/m/10967.1577562752@sss.pgh.pa.us

1 files changed, 2 insertions, 0 deletions

diff --git a/configure b/configure
index 5a1019b484..d2d63f2e55 100755
--- a/configure
+++ b/configure
@@ -706,6 +706,7 @@ with_libxml
 XML2_CONFIG
 UUID_EXTRA_OBJS
 with_uuid
+with_readline
 with_systemd
 with_selinux
 with_openssl
@@ -8000,6 +8001,7 @@ $as_echo "$as_me: WARNING: *** Readline does not work on MinGW --- disabling" >&
 fi
 
 
+
 #
 # Prefer libedit
 #