[fix] OpenSSL::PKey::DH#set_pqg regression (#300)

introduced at: adcd031

Author: kares

lib/jopenssl/_compat23.rb

@@ -14,9 +14,9 @@ def set_key(pub_key, priv_key)
 
       def set_pqg(p, q, g)
         self.p = p
-        if respond_to?(:q)
+        if respond_to?(:q=)
           self.q = q
-        else # TODO self.q = q
+        else
           OpenSSL.warn "JRuby-OpenSSL does not support setting q param on #{inspect}" if q
         end
         self.g = g

src/test/ruby/test_pkey.rb

@@ -83,6 +83,20 @@ def test_pkey_pem_file_error
     end
   end
 
+  def test_pkey_dh
+    dh = OpenSSL::PKey::DH.new
+    assert_equal nil, dh.p
+    assert_equal nil, dh.priv_key
+
+    # OpenSSL::PKey::PKeyError: dh#set_pqg= is incompatible with OpenSSL 3.0
+    if defined? JRUBY_VERSION
+      dh.set_pqg(1_000_000, nil, 10)
+      assert_equal 1_000_000, dh.p
+      assert_equal 10, dh.g
+    end
+    assert_equal nil, dh.q
+  end
+
   def test_to_java
     pkey = OpenSSL::PKey.read(KEY)
     assert_kind_of java.security.PublicKey, pkey.to_java