From c5af9aa2ccab078cf6f5bf68b88a3defa2f768f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Sat, 13 May 2017 16:40:09 -0400
Subject: [PATCH] shared/logs-show: avoid printing "(null)" when timestamp is
 not specified

$ perl -e 'print("MESSAGE\n", pack("q<", 1), "A\n\nMESSAGE=test2\n")' > message.bin
$ systemd-journal-remote -o /tmp/out.journal message.bin
$ journalctl -o export --file /tmp/out.journal
__CURSOR=s=b16c464c2db44384b29e75a564d8388e;i=1;b=6b0be47627bd4932913dc126012c21c0;m=0;t=0;x=b04263a253e357a
__REALTIME_TIMESTAMP=0
__MONOTONIC_TIMESTAMP=0
_BOOT_ID=6b0be47627bd4932913dc126012c21c0
MESSAGE=A

$ journalctl -o verbose --file /tmp/out.journal
(null) [s=b16c464c2db44384b29e75a564d8388e;i=1;b=6b0be47627bd4932913dc126012c21c0;m=0;t=0;x=b04263a253e357a]
    MESSAGE=A

This is changed to
$ build/journalctl -o verbose --file /tmp/out.journal
(no timestamp) [s=b16c464c2db44384b29e75a564d8388e;i=1;b=6b0be47627bd4932913dc126012c21c0;m=0;t=0;x=b04263a253e357a]
    MESSAGE=A

We should deal gracefully with unexpected input.

(cherry picked from commit 8924973ae2e1f0a0c131dcec0578669dc26e5e26)
---
 src/shared/logs-show.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/shared/logs-show.c b/src/shared/logs-show.c
index 72c43e80cb..b4c72215c4 100644
--- a/src/shared/logs-show.c
+++ b/src/shared/logs-show.c
@@ -473,6 +473,7 @@ static int output_verbose(
         _cleanup_free_ char *cursor = NULL;
         uint64_t realtime = 0;
         char ts[FORMAT_TIMESTAMP_MAX + 7];
+        const char *timestamp;
         int r;
 
         assert(f);
@@ -508,10 +509,10 @@ static int output_verbose(
         if (r < 0)
                 return log_error_errno(r, "Failed to get cursor: %m");
 
+        timestamp = flags & OUTPUT_UTC ? format_timestamp_us_utc(ts, sizeof ts, realtime)
+                                       : format_timestamp_us(ts, sizeof ts, realtime);
         fprintf(f, "%s [%s]\n",
-                flags & OUTPUT_UTC ?
-                format_timestamp_us_utc(ts, sizeof(ts), realtime) :
-                format_timestamp_us(ts, sizeof(ts), realtime),
+                timestamp ?: "(no timestamp)",
                 cursor);
 
         JOURNAL_FOREACH_DATA_RETVAL(j, data, length, r) {