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/contrib/pg_upgrade/server.c b/contrib/pg_upgrade/server.c
index 0940e00a725c67a4c37f4c2b6cee3a136f382fe0..22555330684528dfc56dc4fec5a18d814267ba9b 100644 (file)
--- a/contrib/pg_upgrade/server.c
+++ b/contrib/pg_upgrade/server.c
@@ -175,10 +175,11 @@ start_postmaster(ClusterInfo *cluster)
 {
    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);