+start_test "fix RFC 2047 encoded header parameters"
+cat >"$expected" <<EOF
+To: recipient@example.com
+From: sender@example.com
+Date: Wed, 28 Sep 2016 11:24:28 -0400
+Subject: invalid header parameter encoding
+MIME-Version: 1.0
+Content-Type: multipart/mixed; boundary=001a114dd3e8fe9c56053d92f414
+Content-Transfer-Encoding: 8bit
+
+--001a114dd3e8fe9c56053d92f414
+Content-Type: text/plain; charset=UTF-8
+
+This is a test.
+
+--001a114dd3e8fe9c56053d92f414
+Content-Type: text/plain; charset="UTF-8"; name*=UTF-8''test%C3%B8.txt
+Content-Disposition: attachment; filename*=UTF-8''test%C3%B8.txt
+Content-Transfer-Encoding: 8bit
+
+This is the first text/plain part, in a subpart. The file name
+is testø.txt.
+
+--001a114dd3e8fe9c56053d92f414--
+EOF
+
+cat >`mhpath new` <<EOF
+To: recipient@example.com
+From: sender@example.com
+Date: Wed, 28 Sep 2016 11:24:28 -0400
+Subject: invalid header parameter encoding
+MIME-Version: 1.0
+Content-Type: multipart/mixed; boundary=001a114dd3e8fe9c56053d92f414
+
+--001a114dd3e8fe9c56053d92f414
+Content-Type: text/plain; charset=UTF-8
+
+This is a test.
+
+--001a114dd3e8fe9c56053d92f414
+Content-Type: text/plain; charset=UTF-8; name="=?UTF-8?B?dGVzdMO4LnR4dA==?="
+Content-Disposition: attachment; filename="=?UTF-8?B?dGVzdMO4LnR4dA==?="
+Content-Transfer-Encoding: 8bit
+
+This is the first text/plain part, in a subpart. The file name
+is testø.txt.
+
+--001a114dd3e8fe9c56053d92f414--
+EOF
+run_prog mhfixmsg -file - -outfile - <`mhpath last` >"$actual" 2>/dev/null
+check "$expected" "$actual"
+
+