Fix thinko when ending progress report for a backend

The logic ending progress reporting for a backend entry introduced by
b6fb647 causes callers of pgstat_progress_end_command() to do some extra
work when track_activities is enabled as the process fields are reset in
the backend entry even if no command were started for reporting.

This resets the fields only if a command is registered for progress
reporting, and only if track_activities is enabled.

Author: Masahiho Sawada
Discussion: https://postgr.es/m/CAD21AoCry_vJ0E-m5oxJXGL3pnos-xYGCzF95rK5Bbi3Uf-rpA@mail.gmail.com
Backpatch-through: 9.6

diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index b4f2b28b517fbe58410d215398b938ae7fc7bb55..099e14d35e66253cbf90a9b925e743e6063ce4f3 100644 (file)
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -3272,10 +3272,10 @@ pgstat_progress_end_command(void)
 {
    volatile PgBackendStatus *beentry = MyBEEntry;
 
-   if (!beentry)
+   if (!beentry || !pgstat_track_activities)
        return;
-   if (!pgstat_track_activities
-       && beentry->st_progress_command == PROGRESS_COMMAND_INVALID)
+
+   if (beentry->st_progress_command == PROGRESS_COMMAND_INVALID)
        return;
 
    PGSTAT_BEGIN_WRITE_ACTIVITY(beentry);