[PATCH 5/8] mbox_reader: add ->reads method to avoid nonsensical formats

[Eric Wong <e@80x24.org>]

Relying on UNIVERSAL::can may cause internal helper methods
to be used, which can lead to failures or nonsensical results.
---
 lib/PublicInbox/InboxWritable.pm | 2 +-
 lib/PublicInbox/LeiImport.pm     | 2 +-
 lib/PublicInbox/LeiInput.pm      | 4 ++--
 lib/PublicInbox/MboxReader.pm    | 5 +++++
 4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/lib/PublicInbox/InboxWritable.pm b/lib/PublicInbox/InboxWritable.pm
index c2baeba6..eeebc485 100644
--- a/lib/PublicInbox/InboxWritable.pm
+++ b/lib/PublicInbox/InboxWritable.pm
@@ -172,7 +172,7 @@ sub _mbox_eml_cb { # MboxReader->mbox* callback
 sub import_mbox {
 	my ($self, $fh, $variant) = @_;
 	require PublicInbox::MboxReader;
-	my $cb = PublicInbox::MboxReader->can($variant) or
+	my $cb = PublicInbox::MboxReader->reads($variant) or
 		die "$variant not supported\n";
 	my $im = $self->importer(1);
 	$cb->(undef, $fh, \&_mbox_eml_cb, $im, $self->filter);
diff --git a/lib/PublicInbox/LeiImport.pm b/lib/PublicInbox/LeiImport.pm
index e769fba8..e587ada8 100644
--- a/lib/PublicInbox/LeiImport.pm
+++ b/lib/PublicInbox/LeiImport.pm
@@ -96,7 +96,7 @@ error reading $input: $!
 			my $eml = PublicInbox::Eml->new(\$buf);
 			_import_eml($eml, $lei, $kw);
 		} else { # some mbox (->can already checked in call);
-			my $cb = PublicInbox::MboxReader->can($ifmt) //
+			my $cb = PublicInbox::MboxReader->reads($ifmt) //
 				die "BUG: bad fmt=$ifmt";
 			$cb->(undef, $fh, \&_import_eml, $lei, $kw);
 		}
diff --git a/lib/PublicInbox/LeiInput.pm b/lib/PublicInbox/LeiInput.pm
index 89585a52..776b3151 100644
--- a/lib/PublicInbox/LeiInput.pm
+++ b/lib/PublicInbox/LeiInput.pm
@@ -18,7 +18,7 @@ sub check_input_format ($;$) {
 	require PublicInbox::MboxReader;
 	return 1 if $fmt eq 'eml';
 	# XXX: should this handle {gz,bz2,xz}? that's currently in LeiToMail
-	PublicInbox::MboxReader->can($fmt) or
+	PublicInbox::MboxReader->reads($fmt) or
 		return $lei->fail("--$opt_key=$fmt unrecognized");
 	1;
 }
@@ -53,7 +53,7 @@ sub prepare_inputs {
 			if (-f $input_path) {
 				require PublicInbox::MboxLock;
 				require PublicInbox::MboxReader;
-				PublicInbox::MboxReader->can($ifmt) or return
+				PublicInbox::MboxReader->reads($ifmt) or return
 					$lei->fail("$ifmt not supported");
 			} elsif (-d _) {
 				require PublicInbox::MdirReader;
diff --git a/lib/PublicInbox/MboxReader.pm b/lib/PublicInbox/MboxReader.pm
index f93c2ec6..6302d1fa 100644
--- a/lib/PublicInbox/MboxReader.pm
+++ b/lib/PublicInbox/MboxReader.pm
@@ -133,4 +133,9 @@ sub mboxcl2 {
 
 sub new { bless \(my $x), __PACKAGE__ }
 
+sub reads {
+	my $ifmt = $_[-1];
+	$ifmt =~ /\Ambox(?:rd|cl|cl2|o)\z/ ? __PACKAGE__->can($ifmt) : undef
+}
+
 1;