From e5105949d606f6e07035bd5d60f1b1d94d42abbe Mon Sep 17 00:00:00 2001
From: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name>
Date: Mon, 21 Nov 2022 17:49:28 +0100
Subject: [PATCH] ssh_filter_btrbk.sh: use more common exit statuses
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POSIX designates a number of exit statuses around `127` for special use and GNU
a few further.
Further, using values >127 is rather uncommon for normal use-cases.

Use `1` when the SSH command was rejected and `2` when the program’s arguments
could not be parsed).

Since this might at least in principle be used by 3rd-party programs, added a
specific note to the changelog.

Signed-off-by: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name>
---
 ChangeLog           | 6 ++++++
 ssh_filter_btrbk.sh | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 7b348b2..c9373c4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+btrbk-current
+
+  * ssh_filter_btrbk.sh uses new exit statuses on failures (1 when the
+    SSH command was rejected, 2 when the program’s arguments could not
+    be parsed).
+
 btrbk-0.32.5
 
   * Correct handling of zero-size raw info file (close #491).
diff --git a/ssh_filter_btrbk.sh b/ssh_filter_btrbk.sh
index 20ef87c..94cb69c 100755
--- a/ssh_filter_btrbk.sh
+++ b/ssh_filter_btrbk.sh
@@ -42,7 +42,7 @@ reject_and_die()
     local reason="$1"
     log_cmd 'auth.err' 'btrbk REJECT' "$reason"
     printf 'ERROR: ssh_filter_btrbk.sh: ssh command rejected: %s: %s\n' "$reason" "$SSH_ORIGINAL_COMMAND" 1>&2
-    exit 255
+    exit 1
 }
 
 run_cmd()
@@ -166,7 +166,7 @@ while [ "$#" -ge 1 ]; do
 
       *)
           printf 'ERROR: ssh_filter_btrbk.sh: failed to parse command line option: %s\n' "$key" 1>&2
-          exit 255
+          exit 2
           ;;
     esac
     shift