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 818417a5fff0d39399a17f1a1509f6b827a20d7c..c55f4b7745874b91f5a6f0e43d1c694a326081b9 100644 (file)
--- a/contrib/pg_upgrade/server.c
+++ b/contrib/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);