btrbk: allow trailing comments in btrbk.conf

ChangeLog

@@ -9,6 +9,7 @@ btrbk-current
   * Add "backend btrfs-progs-sudo" configuration option (close #115).
   * Show aggregate "size" and "used" for "usage" action (close #119).
   * Add "raw_target_split" configuration option (close #125).
+  * Allow trailing comments in btrbk.conf (close #129).
   * Bugfix: rate limiting must be done after compression (close #134).
   * raw_target_encrypt: Always set "gpg --no-random-seed-file":
     prevents creation of "~/.gnupg/random_seed" with slight perfomance

btrbk

@@ -2902,14 +2902,14 @@ sub parse_config(@)
   open(FILE, '<', $file) or die $!;
   while (<FILE>) {
     chomp;
-    next if /^\s*#/; # ignore comments
+    s/#.*//;         # remove comments
+    s/\s*$//;        # remove trailing whitespace
     next if /^\s*$/; # ignore empty lines
     TRACE "config: parsing line $. with context=$cur->{CONTEXT}: \"$_\"";
     if(/^(\s*)([a-zA-Z_]+)\s+(.*)$/)
     {
       # NOTE: we do not perform checks on indentation!
       my ($indent, $key, $value) = (length($1), lc($2), $3);
-      $value =~ s/\s*$//;
       $cur = parse_config_line($file, $root, $cur, $key, $value);
       unless(defined($cur)) {
         # error, bail out

doc/btrbk.conf.5

@@ -19,6 +19,9 @@ defined either globally or within a section.
 The options specified always apply to the last section encountered,
 superseding the values set in upper-level sections. This means that
 global options must be set before any sections are defined.
+.PP
+Blank lines are ignored. A hash character (#) starts a comment
+extending until end of line.
 .SH SECTIONS
 .PP
 \fBvolume\fR  <volume\-directory>|<url>
@@ -305,9 +308,6 @@ For convenience, it is also possible to set \fIbackend_local\fR or
 local or remote sources/targets (e.g. "backend_remote
 btrfs-progs-btrbk").
 .RE
-.PP
-Lines that contain a hash character (#) in the first column are
-treated as comments.
 .SH RETENTION POLICY
 btrbk uses separate retention policies for snapshots and backups,
 which are defined by the \fIsnapshot_preserve_min\fR,