check defined return value for localized slurp errors

Reading from regular files (even on STDIN) can fail
when dealing with flakey storage.

1 files changed, 3 insertions, 6 deletions

diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index 1b9b56ff..af6380a7 100644
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -210,12 +210,9 @@ sub over {
 
 sub try_cat {
         my ($path) = @_;
-        my $rv = '';
-        if (open(my $fh, '<', $path)) {
-                local $/;
-                $rv = <$fh>;
-        }
-        $rv;
+        open(my $fh, '<', $path) or return '';
+        local $/;
+        <$fh> // '';
 }
 
 sub cat_desc ($) {