Reject missing database name in pg_regress and cohorts.

Writing "pg_regress --dbname= ..." led to a crash, because
we weren't expecting there to be no database name supplied.
It doesn't seem like a great idea to run regression tests
in whatever is the user's default database; so rather than
supporting this case let's explicitly reject it.

Per report from Xing Guo.  Back-patch to all supported
branches.

Discussion: https://postgr.es/m/CACpMh+A8cRvtvtOWVAZsCM1DU81GK4DL26R83y6ugZ1osV=ifA@mail.gmail.com

diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index 931872ba45acfc91dae1d5f8861920837367772b..25683a78413151c7e2e2efa3614a10c3fbc3edc7 100644 (file)
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -2277,6 +2277,17 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
        optind++;
    }
 
+   /*
+    * We must have a database to run the tests in; either a default name, or
+    * one supplied by the --dbname switch.
+    */
+   if (!(dblist && dblist->str && dblist->str[0]))
+   {
+       fprintf(stderr, _("%s: no database name was specified\n"),
+               progname);
+       exit(2);
+   }
+
    if (config_auth_datadir)
    {
 #ifdef ENABLE_SSPI