ensure the query is a string earlier in the Mysql2::Client#query codepath for 1.9

ext/mysql2/client.c

@@ -290,6 +290,7 @@ static VALUE rb_mysql_client_query(int argc, VALUE * argv, VALUE self) {
     opts = defaults;
   }
 
+  Check_Type(args.sql, T_STRING);
 #ifdef HAVE_RUBY_ENCODING_H
   rb_encoding *conn_enc = rb_to_encoding(wrapper->encoding);
   // ensure the string is in the encoding the connection is expecting

spec/mysql2/client_spec.rb

@@ -86,6 +86,12 @@ describe Mysql2::Client do
   end
 
   context "#query" do
+    it "should only accept strings as the query parameter" do
+      lambda {
+        @client.query ["SELECT 'not right'"]
+      }.should raise_error(TypeError)
+    end
+
     it "should accept an options hash that inherits from Mysql2::Client.default_query_options" do
       @client.query "SELECT 1", :something => :else
       @client.query_options.should eql(@client.query_options.merge(:something => :else))