No git compressed, --system-config, added_hash() deep. zsh-completion…

… help

ChangeLog

@@ -1,5 +1,14 @@
 # ChangeLog for squashmount
 
+*squashmount-16.0.0
+	Martin Väth <martin at mvath.de>:
+	- docs/examples: Exclude git compressed files for recompression
+	- New option --system-config and default to {/usr,}/lib/squashmount.pl
+	- Let standard_mount() and added_hash() add array-references to
+	  array-references or strings, and hash-references to hash-references
+	  (recursively).
+	- Formulate zsh-completion help in a more standard manner
+
 *squashmount-15.4.3_p2
 	Martin Väth <martin at mvath.de>:
 	- Remove CapabilityBoundingSet: It breaks overlay and possibly others

README

@@ -171,9 +171,13 @@ Note that the hook-file in this directory treats the mount point "gentoo"
 specially! See the example configuration in etc/squashmount.pl how to
 setup an appropriate mount point "gentoo" for this setting.
 
-In all cases you have to copy etc/squashmount.pl to /etc/squashmount.pl
+In all cases you have to copy lib/squashmount.pl to /etc/squashmount.pl
 and adapt it to your need! This is an essential point of squashmount,
 and it is impossible to use squashmount without setting up the configuration.
+You can optionally also copy lib/squashmount.pl to /lib/squashmount.pl or
+/usr/lib/squashmount.pl to provide a system-wide example config.
+Alternatively, you can also modify that file to use it as a fallback if
+/etc/squashmount.pl is not readable.
 
 
 Some Examples

bin/squashmount

@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 BEGIN { require 5.022 }
-package Squashmount v15.4.3;
+package Squashmount v16.0.0;
 
 use strict;
 use warnings;
@@ -58,7 +58,9 @@ so that the data is regularly resquashed.
 You can manually force this resquashing by calling B<squashmount remount>.
 
 B<squashmount> reads its mount-points from F</etc/squashmount.pl> which is
-documented later (the path can be changed with B<--config>).
+documented later (the path can be changed with B<--config>, and there are
+system fallbacks F</usr/lib/squashmount.pl> and F</lib/squashmount.pl> which
+can be changed with B<--system-config>).
 Configured directories are created if necessary; B<squashmount> never removes
 directories (not even configured temporary directories).
 
@@ -424,6 +426,17 @@ Print version number and exit
 Using I<file> instead of B</etc/squashmount.pl> as a config file.
 If this option is repeated, all passed B<file>s are parsed in the given order.
 
+=item B<--system-config=>I<file> (accumulative)
+
+If the file B</etc/squashmount.pl> cannot be read successfully
+(or if none of the files specified by B<--config> can be read, respectively),
+then the first successfully read file from the system config list
+B</usr/lib/squashmount.pl> or B</lib/squashmount.pl> is used instead.
+When this option is specified, that list is replaced by the filenames
+specified by this option.
+Note that in contrast to B<--config> only the first readable file is used,
+and also this only if all of the regular configuration files fail.
+
 =item B<--umount=>I<opt> or B<-u> I<opt> (accumulative)
 
 Add option I<opt> to the default B<@umount> array (see also B<--umount-ro>).
@@ -958,7 +971,7 @@ see the remarks at the end of this manpage.)
 
 =item DIR => '/usr/local',
 
-=item FILE => '/usr/local.sfs'
+=item FILE => '/usr/local.sfs',
 
 =back
 
@@ -990,7 +1003,7 @@ see the remarks at the end of this manpage.)
 
 =item RM_READONLY => 1,  # remove temporary READONLY on stop
 
-=item RM_WORKDIR => 1  # remove temporary WORKDIR on stop
+=item RM_WORKDIR => 1,  # remove temporary WORKDIR on stop
 
 =back
 
@@ -1012,7 +1025,7 @@ see the remarks at the end of this manpage.)
 
 =item DIFF => [ qr{^ls-R$},
 
-=item qr{^tex(/generic(/config(/language(\.(dat(\.lua)?|def)))?)?)?$}n ]
+=item qr{^tex(/generic(/config(/language(\.(dat(\.lua)?|def)))?)?)?$}n ],
 
 =back
 
@@ -1044,6 +1057,12 @@ see the remarks at the end of this manpage.)
 
 =item READONLY => '/usr/portage.mount/readonly',
 
+=item MKSQUASHFS => [ # Do not recompress git-compressed data
+
+=item # See https://github.com/plougher/squashfs-tools/issues/24
+
+=item '-action', 'uncompressed@subpathname(*/.git/objects/pack)' ],
+
 =item THRESHOLD => '40m',  # resquash on umount if 40 MB changed, or
 
 =item # if local/* (with * not .git, profiles, metadata) changed:
@@ -1054,7 +1073,7 @@ see the remarks at the end of this manpage.)
 
 =item # be more explicit about the changes you do not care about, e.g.:
 
-=item # DIFF => qr{^local(/profiles(/use\.local\.desc)?)?$}n
+=item # DIFF => qr{^local(/profiles(/use\.local\.desc)?)?$}n,
 
 =back
 
@@ -1082,7 +1101,7 @@ see the remarks at the end of this manpage.)
 
 =item SKIPDIR => qr{(^|/)tmp}ni,  # tmp* Tmp* TMP*
 
-=item SKIPFUNC => sub { my ($rel, $abs, $ro) = @_; return (-d $abs) }
+=item SKIPFUNC => sub { my ($rel, $abs, $ro) = @_; return (-d $abs) },
 
 =back
 
@@ -1393,8 +1412,8 @@ The intention is that this function can be used to return e.g. a temporary
 dir name by using something like as in the B<fancy_temporary> example above.
 
 Be aware that if this function uses B<File::Temp::newdir>, it should pass
-B<CLEANUP =E<gt> ''> to avoid that the directory is magically removed recursively:
-Forgetting this can severely damage your data!
+B<CLEANUP =E<gt> ''> to avoid that the directory is magically removed
+recursively: Forgetting this can severely damage your data!
 
 As an exception, if the function returns the corresponding created object
 (and not only a filename as in the B<make_temporary_subdir> example above),
@@ -1845,8 +1864,12 @@ In addition, the values for the keys B<CHANGES>, B<WORKDIR>, B<READONLY>,
 and B<FILE> are generated by just appending B<.mount/changes>,
 B<.mount/workdir>, B<.mount/readonly>, B<.mount/>I<dirname>B<.sfs>.
 Moreover, if I<...> are references to hashes, they are added to the hash:
-Later hashes override earlier ones; setting a value to C<undef> in a sense
-cancels a previous definition.
+Later hash entries override earlier ones unless the values itself are hashes
+or arrays; so, for instance setting a value to C<undef> in a sense cancels
+a previous definition. If a hash entry itself is a hash or array reference,
+it does not replace the previous value but is added to it (provided that
+the previous value was a hash or array reference or a single string,
+respectively). Adding hash references to hash references works recursively.
 
 =item B<added_hash(>I<hashref>B<,> ...B<)>
 
@@ -1856,9 +1879,9 @@ not fill a hash with certain values first.
 The idea is that this function can be used to start with a "default" hash
 and override/modify/add some data at your discretion.
 
-For perl specialists: This function is practically the same as that provided
+For perl specialists: This function is similar to the one provided
 by B<Hash::Merge::Simple>, but it does not require the existence of that
-perl module, and it does not work recursively.
+perl module and can add arrays to strings.
 
 =back
 
@@ -1877,7 +1900,7 @@ B<THRESHOLD> option) in a shorter way:
 
 =over 24
 
-=item THRESHOLD => '40m'
+=item THRESHOLD => '40m',
 
 =back
 
@@ -1908,13 +1931,23 @@ Here is such an example which also demonstrates the use of B<added_hash()>:
 
 =item my $defaults =  added_hash($always, { BACKUP => '.bak' }, $tempdir);
 
+=item # Adding $git will not recompress git-compressed data.
+
+=item # See https://github.com/plougher/squashfs-tools/issues/24
+
+=item my $git = { MKSQUASHFS => [
+
+=item '-action', 'uncompressed@subpathname(*/.git/objects/pack)' ],
+
+=item };
+
 =item push(@mounts,
 
 =over 16
 
-=item standard_mount('portage', '/usr/portage', $defaults),
+=item standard_mount('portage', '/usr/portage', $defaults, $git),
 
-=item standard_mount('kernel', '/usr/src', $defaults),
+=item standard_mount('kernel', '/usr/src', $defaults, $git),
 
 =item standard_mount('games', '/usr/share/games', $defaults, {
 
@@ -2371,6 +2404,7 @@ my $errorbreak = '';
 my $fatalreturn = undef;
 my $firstmatch = '';
 my @configs = ();
+my @system_configs = ();
 my @argv = ();
 my $separator = "\n";
 my $rundir = undef;
@@ -3588,11 +3622,11 @@ sub read_config_file {
 	my ($file) = @_;
 	$file = &bad_abs_path($file);
 	unless(defined($file)) {
-		&warning('skipping config file ' . $_[0] . ' (not a valid path)') unless($quiet);
+		&warning('skipping config file ' . $_[0] . ' (not a valid path)') unless($verbose);
 		return
 	}
-	unless(-f $file) {
-		&warning("skipping config file $file (not a file)") unless($quiet);
+	if((-d $file) || !(-r $file)) {
+		&warning("skipping config file $file (not a readable file)") if($verbose);
 		return
 	}
 	&info("reading config file $file") if($verbose > 2);
@@ -3650,24 +3684,49 @@ sub added_hash(@) {
 	my $a = {};
 	for my $i (@_) {
 		unless(defined($i) && (ref($i) eq 'HASH')) {
-			&warning('wrong argument in &added_hash() or &standard_mount():',
+			&warning('wrong argument in added_hash() or standard_mount():',
 				'hash reference expected');
 			next
 		}
 		for my $j (keys(%$i)) {
-			$a->{$j} = $i->{$j}
+			unless(exists($a->{$j})) {
+				$a->{$j} = $i->{$j};
+				next
+			}
+			my $type = ref($i->{$j});
+			if($type eq 'HASH') {
+				if(ref($a->{$j}) eq 'HASH') {
+					$a->{$j} = &added_hash($a->{$j}, $i->{$j})
+				} else {
+					$a->{$j} = $i->{$j}
+				}
+			} elsif($type eq 'ARRAY') {
+				my $source = $i->{$j};
+				my $aref = ref($a->{$j});
+				if($aref eq 'ARRAY') {
+					my $arrayref = $a->{$j};
+					push(@$arrayref, @$source)
+				} elsif(($aref eq '') && defined($a->{$j})) {
+					$a->{$j} = [ $a->{$j}, @$source ]
+				} else {
+					$a->{$j} = $source
+				}
+			} else {
+				$a->{$j} = $i->{$j}
+			}
 		}
 	}
 	$a
 }
 
 sub standard_mount($$@) {
-	my ($tag, $dir, @rest) = @_;
-	&fatal('first argument of &standard_mount() should be a (nonempty) tag')
+	my $tag = shift();
+	my $dir = shift();
+	&fatal('first argument of standard_mount() should be a (nonempty) tag')
 		unless(defined($tag) && (ref(\$tag) eq 'SCALAR') && ($tag ne ''));
 	# Checking for -d $dir might be wrong: the config might use
 	# this as a flag and not add the result to @mounts later on
-	&fatal('error: second argument of &standard_mount() should be a directory')
+	&fatal('error: second argument of standard_mount() should be a directory')
 		unless(defined($dir) && (ref(\$dir) eq 'SCALAR') && ($dir ne ''));
 	$dir = File::Spec->canonpath($dir);
 	&added_hash({
@@ -3678,7 +3737,7 @@ sub standard_mount($$@) {
 		WORKDIR => File::Spec->catdir($dir . '.mount', 'workdir'),
 		FILE => File::Spec->catfile($dir . '.mount',
 			((File::Spec->splitpath($dir))[2]) . '.sfs')
-	}, @rest)
+	}, @_)
 }
 
 # Read settings from /run/squashmount:
@@ -4712,6 +4771,7 @@ Getopt::Long::GetOptions(
 	'man|?', sub { &pod2usage(-verbose => 2, -exit => 0) },
 	'version|V', \&version,
 	'config|c=s', \@configs,
+	'system-config=s', \@system_configs,
 	'umount|u=s', \@CFG::umount,
 	'umount-ro|U=s', \@CFG::umount_ro,
 	'fumount=s', \@CFG::fumount,
@@ -4771,9 +4831,12 @@ if($opt_user) {
 		unless(@configs);
 	$rundir //= File::Spec->catdir($root, 'run', 'squashmount')
 }
+@system_configs = (File::Spec->catfile($root, 'usr', 'lib', 'squashmount.pl'),
+	File::Spec->catfile($root, 'lib', 'squashmount.pl'))
+	unless(@system_configs);
 
 &fatal("$rundir is not an absolute path") unless(&is_abspath($rundir));
-for my $i (@configs) {
+for my $i (@configs, @system_configs) {
 	&fatal("config-file $i is not an absolute path")
 		unless(&is_abspath($i))
 }
@@ -4925,10 +4988,21 @@ $|=1;
 
 {
 	local @ARGV = @argv;
+	my $have_read_config = '';
 	for my $file (@configs) {
-		&read_config_file($file)
+		$have_read_config = 1 if(&read_config_file($file))
+	}
+	unless($have_read_config) {
+		for my $file (@system_configs) {
+			if(&read_config_file($file)) {
+				$have_read_config = 1;
+				last
+			}
+		}
 	}
-	$run_ro = !$CFG::storing
+	$run_ro = !$CFG::storing;
+	fatal('None of the config files could be read:',
+		@configs, @system_configs) unless($have_read_config)
 }
 
 # Modify options according to config: