filter: use file(1) to detect mime type if octet-stream

Some mailers do not correctly detect/set the Content-Type header; so
attempt to keep messages based on our server-detected MIME type if
application/octet-stream was specified.

1 files changed, 35 insertions, 0 deletions

diff --git a/t/filter.t b/t/filter.t
index 12f4ed6f..0aa26a5f 100644
--- a/t/filter.t
+++ b/t/filter.t
@@ -278,5 +278,40 @@ sub count_body_parts {
         is(undef, $f->simple->header("Mail-Followup-To"), "mft stripped");
 }
 
+# multi-part with application/octet-stream
+{
+        my $os = 'application/octet-stream';
+        my $parts = [
+                Email::MIME->create(
+                        attributes => { content_type => $os },
+                        body => <<EOF
+#include <stdio.h>
+int main(void)
+{
+        printf("Hello world\\n");
+        return 0;
+}
+EOF
+                ),
+                Email::MIME->create(
+                        attributes => {
+                                filename => 'zero.data',
+                                encoding => 'base64',
+                                content_type => $os,
+                        },
+                        body => ("\0" x 4096),
+                )
+        ];
+        my $email = Email::MIME->create(
+                header_str => [ From => 'a@example.com', Subject => 'blah' ],
+                parts => $parts,
+        );
+        my $f = Email::Filter->new(data => $email->as_string);
+        is(1, PublicInbox::Filter->run($f->simple), "run was a success");
+        my $parsed = Email::MIME->new($f->simple->as_string);
+        is(scalar $parsed->parts, 1, "only one remaining part");
+        like($f->simple->header("X-Content-Filtered-By"),
+                qr/PublicInbox::Filter/, "XCFB header added");
+}
 
 done_testing();