Do not require an open connection for MySQL string escaping

Author: csfrancis

ext/mysql2/client.c

@@ -38,10 +38,12 @@ static ID intern_brackets, intern_merge, intern_merge_bang, intern_new_with_args
   #define CONNECTED(wrapper) (wrapper->client->net.pvio != NULL && wrapper->client->net.fd != -1 && VIO_IS_CONNECTED(wrapper))
 #endif
 
+#define MYSQL_CLIENT_NOT_CONNECTED_STR "MySQL client is not connected"
+
 #define REQUIRE_CONNECTED(wrapper) \
   REQUIRE_INITIALIZED(wrapper) \
   if (!CONNECTED(wrapper) && !wrapper->reconnect_enabled) { \
-    rb_raise(cMysql2Error, "MySQL client is not connected"); \
+    rb_raise(cMysql2Error, MYSQL_CLIENT_NOT_CONNECTED_STR); \
   }
 
 #define REQUIRE_NOT_CONNECTED(wrapper) \
@@ -50,6 +52,17 @@ static ID intern_brackets, intern_merge, intern_merge_bang, intern_new_with_args
     rb_raise(cMysql2Error, "MySQL connection is already open"); \
   }
 
+/*
+ * assert that we've connected at least once by using
+ * `client->server_version`, which is a string that is initialized to the char*
+ * server name once the client has connected
+ */
+#define REQUIRE_CONNECTED_ONCE(wrapper) \
+   REQUIRE_INITIALIZED(wrapper) \
+   if (!wrapper->client->server_version) { \
+     rb_raise(cMysql2Error, MYSQL_CLIENT_NOT_CONNECTED_STR); \
+   }
+
 /*
  * compatability with mysql-connector-c, where LIBMYSQL_VERSION is the correct
  * variable to use, but MYSQL_SERVER_VERSION gives the correct numbers when
@@ -819,7 +832,7 @@ static VALUE rb_mysql_client_real_escape(VALUE self, VALUE str) {
   rb_encoding *conn_enc;
   GET_CLIENT(self);
 
-  REQUIRE_CONNECTED(wrapper);
+  REQUIRE_CONNECTED_ONCE(wrapper);
   Check_Type(str, T_STRING);
   default_internal_enc = rb_default_internal_encoding();
   conn_enc = rb_to_encoding(wrapper->encoding);

spec/mysql2/client_spec.rb

@@ -887,11 +887,11 @@ def run_gc
       end.not_to raise_error
     end
 
-    it "should require an open connection" do
+    it "should not require an open connection" do
       @client.close
       expect do
         @client.escape ""
-      end.to raise_error(Mysql2::Error)
+      end.not_to raise_error
     end
 
     context 'when mysql encoding is not utf8' do