+test_begin_subtest "notmuch-show should not show unindexed protected subject header in emacs when nm-c-process-mime is nil"
+test_emacs '(let ((notmuch-crypto-process-mime nil))
+ (notmuch-show "id:protected-header@crypto.notmuchmail.org")
+ (test-output))'
+cat <<EOF >EXPECTED
+test_suite@notmuchmail.org (2000-01-01) (encrypted inbox)
+Subject: Subject Unavailable
+To: test_suite@notmuchmail.org
+Date: Sat, 01 Jan 2000 12:00:00 +0000
+
+[ multipart/encrypted ]
+[ Unknown encryption status ]
+[ application/pgp-encrypted ]
+[ application/octet-stream ]
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "notmuch-show should show protected subject header in emacs"
+test_emacs '(notmuch-show "id:protected-header@crypto.notmuchmail.org")
+ (test-output)'
+cat <<EOF >EXPECTED
+test_suite@notmuchmail.org (2000-01-01) (encrypted inbox)
+Subject: This is a protected header
+To: test_suite@notmuchmail.org
+Date: Sat, 01 Jan 2000 12:00:00 +0000
+
+[ multipart/encrypted ]
+[ Decryption successful ]
+[ application/pgp-encrypted ]
+[ text/plain ]
+This is the sekrit message
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+
+# notmuch-emacs still leaks the subject line; as long as it leaks the
+# subject line, it should emit the external subject, not the protected
+# subject, even if it knows what the true subject is:
+test_begin_subtest "Reply within emacs to a message with protected headers, not leaking subject"
+test_emacs "(let ((message-hidden-headers '()))
+ (notmuch-show \"id:protected-header@crypto.notmuchmail.org\")
+ (notmuch-show-reply)
+ (test-output))"
+cat <<EOF >EXPECTED
+From: Notmuch Test Suite <test_suite@notmuchmail.org>
+To: test_suite@notmuchmail.org
+Subject: Re: Subject Unavailable
+In-Reply-To: <protected-header@crypto.notmuchmail.org>
+Fcc: ${MAIL_DIR}/sent
+References: <protected-header@crypto.notmuchmail.org>
+--text follows this line--
+<#secure method=pgpmime mode=signencrypt>
+test_suite@notmuchmail.org writes:
+
+> This is the sekrit message
+EOF
+test_expect_equal_file EXPECTED OUTPUT
+