Register atexit hook only once in pg_upgrade.

start_postmaster() registered stop_postmaster_atexit as an atexit(3)
callback each time through, although the obvious intention was to do
so only once per program run.  The extra registrations were harmless,
so long as we didn't exceed ATEXIT_MAX, but still it's a bug.

Artur Zakirov, with bikeshedding by Kyotaro Horiguchi and me

Discussion: <d279e817-02b5-caa6-215f-cfb05dce109a@postgrespro.ru>

diff --git a/src/bin/pg_upgrade/server.c b/src/bin/pg_upgrade/server.c
index 969e5d63ffba10b593143e49341c5c08746e128e..02b736dbd0bb6fb779d2b3b4808576b6f5db49ad 100644 (file)
--- a/src/bin/pg_upgrade/server.c
+++ b/src/bin/pg_upgrade/server.c
@@ -174,10 +174,11 @@ start_postmaster(ClusterInfo *cluster, bool throw_error)
 {
        char            cmd[MAXPGPATH * 4 + 1000];
        PGconn     *conn;
-       bool            exit_hook_registered = false;
        bool            pg_ctl_return = false;
        char            socket_string[MAXPGPATH + 200];
 
+       static bool exit_hook_registered = false;
+
        if (!exit_hook_registered)
        {
                atexit(stop_postmaster_atexit);