From 4890482531a4c36d0f0fa37a3734fd809d95f305 Mon Sep 17 00:00:00 2001
From: dana <dana@dana.is>
Date: Wed, 6 Mar 2019 19:20:06 -0600
Subject: [PATCH] journalctl: support `-b all` to negate effect of -b

Also fix an issue where -b without argument didn't always behave as -b0
---
 man/journalctl.xml                   |  8 ++++--
 src/journal/journalctl.c             | 38 +++++++++++++++++-----------
 test/TEST-04-JOURNAL/test-journal.sh | 12 +++++++++
 3 files changed, 41 insertions(+), 17 deletions(-)

diff --git a/man/journalctl.xml b/man/journalctl.xml
index 1ea7b24df1..a3c67f5e82 100644
--- a/man/journalctl.xml
+++ b/man/journalctl.xml
@@ -461,8 +461,8 @@
       </varlistentry>
 
       <varlistentry>
-        <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
-        <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
+        <term><option>-b <optional><optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>
+        <term><option>--boot<optional>=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>
 
         <listitem><para>Show messages from a specific boot. This will
         add a match for <literal>_BOOT_ID=</literal>.</para>
@@ -494,6 +494,10 @@
         <replaceable>offset</replaceable> is not specified, a value of
         zero is assumed, and the logs for the boot given by
         <replaceable>ID</replaceable> are shown.</para>
+
+        <para>The special argument <constant>all</constant> can be
+        used to negate the effect of an earlier use of
+        <option>-b</option>.</para>
         </listitem>
       </varlistentry>
 
diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c
index 42a5a09608..f2386762b2 100644
--- a/src/journal/journalctl.c
+++ b/src/journal/journalctl.c
@@ -266,7 +266,11 @@ static int parse_boot_descriptor(const char *x, sd_id128_t *boot_id, int *offset
         sd_id128_t id = SD_ID128_NULL;
         int off = 0, r;
 
-        if (strlen(x) >= 32) {
+        if (streq(x, "all")) {
+                *boot_id = SD_ID128_NULL;
+                *offset = 0;
+                return 0;
+        } else if (strlen(x) >= 32) {
                 char *t;
 
                 t = strndupa(x, 32);
@@ -294,7 +298,7 @@ static int parse_boot_descriptor(const char *x, sd_id128_t *boot_id, int *offset
         if (offset)
                 *offset = off;
 
-        return 0;
+        return 1;
 }
 
 static int help(void) {
@@ -593,30 +597,34 @@ static int parse_argv(int argc, char *argv[]) {
 
                 case ARG_THIS_BOOT:
                         arg_boot = true;
+                        arg_boot_id = SD_ID128_NULL;
+                        arg_boot_offset = 0;
                         break;
 
                 case 'b':
                         arg_boot = true;
+                        arg_boot_id = SD_ID128_NULL;
+                        arg_boot_offset = 0;
 
                         if (optarg) {
                                 r = parse_boot_descriptor(optarg, &arg_boot_id, &arg_boot_offset);
-                                if (r < 0) {
-                                        log_error("Failed to parse boot descriptor '%s'", optarg);
-                                        return -EINVAL;
-                                }
-                        } else {
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to parse boot descriptor '%s'", optarg);
 
-                                /* Hmm, no argument? Maybe the next
-                                 * word on the command line is
-                                 * supposed to be the argument? Let's
-                                 * see if there is one and is parsable
-                                 * as a boot descriptor... */
+                                arg_boot = r;
 
-                                if (optind < argc &&
-                                    parse_boot_descriptor(argv[optind], &arg_boot_id, &arg_boot_offset) >= 0)
+                        /* Hmm, no argument? Maybe the next
+                         * word on the command line is
+                         * supposed to be the argument? Let's
+                         * see if there is one and is parsable
+                         * as a boot descriptor... */
+                        } else if (optind < argc) {
+                                r = parse_boot_descriptor(argv[optind], &arg_boot_id, &arg_boot_offset);
+                                if (r >= 0) {
+                                        arg_boot = r;
                                         optind++;
+                                }
                         }
-
                         break;
 
                 case ARG_LIST_BOOTS:
diff --git a/test/TEST-04-JOURNAL/test-journal.sh b/test/TEST-04-JOURNAL/test-journal.sh
index 260cae09ab..e198cb6ede 100755
--- a/test/TEST-04-JOURNAL/test-journal.sh
+++ b/test/TEST-04-JOURNAL/test-journal.sh
@@ -63,6 +63,18 @@ grep -q '^PRIORITY=6$' /output
 ! grep -q '^FOO=' /output
 ! grep -q '^SYSLOG_FACILITY=' /output
 
+# `-b all` negates earlier use of -b (-b and -m are otherwise exclusive)
+journalctl -b -1 -b all -m > /dev/null
+
+# -b always behaves like -b0
+journalctl -q -b-1 -b0 | head -1 > /expected
+journalctl -q -b-1 -b  | head -1 > /output
+cmp /expected /output
+# ... even when another option follows (both of these should fail due to -m)
+{ journalctl -ball -b0 -m 2>&1 || :; } | head -1 > /expected
+{ journalctl -ball -b  -m 2>&1 || :; } | head -1 > /output
+cmp /expected /output
+
 # Don't lose streams on restart
 systemctl start forever-print-hola
 sleep 3
-- 
2.25.1