Fix for machines that have their time changed forward, then back. Ensure

that any cached lpq information gathered during that time doesn't
stay around for longer than 1 hour.
Jeremy.

2 files changed, 25 insertions, 6 deletions

diff --git a/source/include/printing.h b/source/include/printing.h
index 40fe964a193..bde2bfa6bdb 100644
--- a/source/include/printing.h
+++ b/source/include/printing.h
@@ -1,3 +1,6 @@
+#ifndef PRINTING_H_
+#define PRINTING_H_
+
 /* 
    Unix SMB/Netbios implementation.
    Version 3.0
@@ -65,5 +68,9 @@ extern struct printif	cups_printif;
 #define UNIX_JOB_START PRINT_MAX_JOBID
 #define NEXT_JOBID(j) ((j+1) % PRINT_MAX_JOBID > 0 ? (j+1) % PRINT_MAX_JOBID : 1)
 
+#define MAX_CACHE_VALID_TIME 3600
+
 #define PRINT_SPOOL_PREFIX "smbprn."
 #define PRINT_DATABASE_VERSION 2
+
+#endif /* PRINTING_H_ */
diff --git a/source/printing/printing.c b/source/printing/printing.c
index 6699b703466..82bd2f722c4 100644
--- a/source/printing/printing.c
+++ b/source/printing/printing.c
@@ -775,15 +775,27 @@ int print_job_write(int jobid, const char *buf, int size)
 static BOOL print_cache_expired(int snum)
 {
 	fstring key;
-	time_t t2, t = time(NULL);
+	time_t last_qscan_time, time_now = time(NULL);
 
-	slprintf(key, sizeof(key)-1, "CACHE/%s", lp_servicename(snum));
+	slprintf(key, sizeof(key), "CACHE/%s", lp_servicename(snum));
 	dos_to_unix(key, True);                /* Convert key to unix-codepage */
-	t2 = (time_t)tdb_fetch_int32(tdb, key);
-	if (t2 == ((time_t)-1) || (t - t2) >= lp_lpqcachetime()) {
+	last_qscan_time = (time_t)tdb_fetch_int32(tdb, key);
+
+	/*
+	 * Invalidate the queue for 3 reasons.
+	 * (1). last queue scan time == -1.
+	 * (2). Current time - last queue scan time > allowed cache time.
+	 * (3). last queue scan time > current time + MAX_CACHE_VALID_TIME (1 hour by default).
+	 * This last test picks up machines for which the clock has been moved
+	 * forward, an lpq scan done and then the clock moved back. Otherwise
+	 * that last lpq scan would stay around for a loooong loooong time... :-). JRA.
+	 */
+
+	if (last_qscan_time == ((time_t)-1) || (time_now - last_qscan_time) >= lp_lpqcachetime() ||
+			last_qscan_time > (time_now + MAX_CACHE_VALID_TIME)) {
 		DEBUG(3, ("print cache expired for queue %s \
-(last_cache = %d, time now = %d, qcachetime = %d)\n", lp_servicename(snum),
-			(int)t2, (int)t, (int)lp_lpqcachetime() ));
+(last_qscan_time = %d, time now = %d, qcachetime = %d)\n", lp_servicename(snum),
+			(int)last_qscan_time, (int)time_now, (int)lp_lpqcachetime() ));
 		return True;
 	}
 	return False;