Fix bogus time printout in walreceiver's debug log messages.

The displayed sendtime and receipttime were always exactly equal, because
somebody forgot that timestamptz_to_str returns a static buffer (thereby
simplifying life for most callers, at the cost of complicating it for those
who need two results concurrently).  Apply the same pstrdup solution used
by the other call sites with this issue.  Back-patch to 9.2 where the
faulty code was introduced.  Per bug #9849 from Haruka Takatsuka, though
this is not exactly his patch.

Possibly we should change timestamptz_to_str's API, but I wouldn't want
to do so in the back branches.

diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 7a0102d694bbb3104581768d82fd6c353c22fa5e..88e65d9501c34516a136ee718df8633d89dda187 100644 (file)
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -767,9 +767,19 @@ ProcessWalSndrMessage(XLogRecPtr walEnd, TimestampTz sendTime)
    SpinLockRelease(&walrcv->mutex);
 
    if (log_min_messages <= DEBUG2)
+   {
+       char       *sendtime;
+       char       *receipttime;
+
+       /* Copy because timestamptz_to_str returns a static buffer */
+       sendtime = pstrdup(timestamptz_to_str(sendTime));
+       receipttime = pstrdup(timestamptz_to_str(lastMsgReceiptTime));
        elog(DEBUG2, "sendtime %s receipttime %s replication apply delay %d ms transfer latency %d ms",
-            timestamptz_to_str(sendTime),
-            timestamptz_to_str(lastMsgReceiptTime),
+            sendtime,
+            receipttime,
             GetReplicationApplyDelay(),
             GetReplicationTransferLatency());
+       pfree(sendtime);
+       pfree(receipttime);
+   }
 }