1 files changed, 70 insertions, 0 deletions
diff --git a/lib/PublicInbox/Umask.pm b/lib/PublicInbox/Umask.pm
new file mode 100644
index 00000000..2c859e65
--- /dev/null
+++ b/lib/PublicInbox/Umask.pm
@@ -0,0 +1,70 @@
+# Copyright (C) all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# base class to ensures Xapian||SQLite files respect core.sharedRepository
+# of git repos
+package PublicInbox::Umask;
+use v5.12;
+use PublicInbox::OnDestroy;
+
+use constant {
+        PERM_UMASK => 0,
+        OLD_PERM_GROUP => 1,
+        OLD_PERM_EVERYBODY => 2,
+        PERM_GROUP => 0660,
+        PERM_EVERYBODY => 0664,
+};
+
+sub _read_git_config_perm {
+        my ($self) = @_;
+        chomp(my $perm = $self->git->qx('config', 'core.sharedRepository'));
+        $perm;
+}
+
+sub _git_config_perm {
+        my $self = shift;
+        my $perm = scalar @_ ? $_[0] : _read_git_config_perm($self);
+        $perm //= '';
+        return PERM_UMASK if $perm eq '' || $perm eq 'umask';
+        return PERM_GROUP if $perm eq 'group';
+        return PERM_EVERYBODY if $perm =~ /\A(?:all|world|everybody)\z/;
+        return PERM_GROUP if ($perm =~ /\A(?:true|yes|on|1)\z/);
+        return PERM_UMASK if ($perm =~ /\A(?:false|no|off|0)\z/);
+
+        my $i = oct($perm);
+        return PERM_UMASK if $i == PERM_UMASK;
+        return PERM_GROUP if $i == OLD_PERM_GROUP;
+        return PERM_EVERYBODY if $i == OLD_PERM_EVERYBODY;
+
+        if (($i & 0600) != 0600) {
+                die "core.sharedRepository mode invalid: ".
+                    sprintf('%.3o', $i) . "\nOwner must have permissions\n";
+        }
+        ($i & 0666);
+}
+
+sub _umask_for {
+        my ($perm) = @_; # _git_config_perm return value
+        my $rv = $perm;
+        return umask if $rv == 0;
+
+        # set +x bit if +r or +w were set
+        $rv |= 0100 if ($rv & 0600);
+        $rv |= 0010 if ($rv & 0060);
+        $rv |= 0001 if ($rv & 0006);
+        (~$rv & 0777);
+}
+
+sub with_umask {
+        my ($self, $cb, @arg) = @_;
+        my $old = umask($self->{umask} //= umask_prepare($self));
+        my $restore = on_destroy \&CORE::umask, $old;
+        $cb ? $cb->(@arg) : $restore;
+}
+
+sub umask_prepare {
+        my ($self) = @_;
+        _umask_for(_git_config_perm($self));
+}
+
+1;