a couple of minor updates to connection management with some specs

ext/mysql2/client.c

@@ -186,7 +186,9 @@ static VALUE rb_connect(VALUE self, VALUE user, VALUE pass, VALUE host, VALUE po
 static VALUE rb_mysql_client_close(VALUE self) {
   GET_CLIENT(self);
 
+  if (!wrapper->closed) {
     rb_thread_blocking_region(nogvl_close, wrapper, RUBY_UBF_IO, 0);
+  }
 
   return Qnil;
 }
@@ -335,6 +337,7 @@ static VALUE rb_mysql_client_escape(VALUE self, VALUE str) {
   unsigned long newLen, oldLen;
   GET_CLIENT(self);
 
+  REQUIRE_OPEN_DB(wrapper);
   Check_Type(str, T_STRING);
 #ifdef HAVE_RUBY_ENCODING_H
   rb_encoding *default_internal_enc = rb_default_internal_encoding();
@@ -346,7 +349,6 @@ static VALUE rb_mysql_client_escape(VALUE self, VALUE str) {
   oldLen = RSTRING_LEN(str);
   newStr = rb_str_new(0, oldLen*2+1);
 
-  REQUIRE_OPEN_DB(wrapper);
   newLen = mysql_real_escape_string(wrapper->client, RSTRING_PTR(newStr), StringValuePtr(str), oldLen);
   if (newLen == oldLen) {
     // no need to return a new ruby string if nothing changed
@@ -366,6 +368,7 @@ static VALUE rb_mysql_client_escape(VALUE self, VALUE str) {
 static VALUE rb_mysql_client_info(VALUE self) {
   VALUE version = rb_hash_new(), client_info;
   GET_CLIENT(self);
+
 #ifdef HAVE_RUBY_ENCODING_H
   rb_encoding *default_internal_enc = rb_default_internal_encoding();
   rb_encoding *conn_enc = rb_to_encoding(wrapper->encoding);
@@ -386,13 +389,13 @@ static VALUE rb_mysql_client_info(VALUE self) {
 static VALUE rb_mysql_client_server_info(VALUE self) {
   VALUE version, server_info;
   GET_CLIENT(self);
+
+  REQUIRE_OPEN_DB(wrapper);
 #ifdef HAVE_RUBY_ENCODING_H
   rb_encoding *default_internal_enc = rb_default_internal_encoding();
   rb_encoding *conn_enc = rb_to_encoding(wrapper->encoding);
 #endif
 
-  REQUIRE_OPEN_DB(wrapper);
-
   version = rb_hash_new();
   rb_hash_aset(version, sym_id, LONG2FIX(mysql_get_server_version(wrapper->client)));
   server_info = rb_str_new2(mysql_get_server_info(wrapper->client));
@@ -408,11 +411,13 @@ static VALUE rb_mysql_client_server_info(VALUE self) {
 
 static VALUE rb_mysql_client_socket(VALUE self) {
   GET_CLIENT(self);
+  REQUIRE_OPEN_DB(wrapper);
   return INT2NUM(wrapper->client->net.fd);
 }
 
 static VALUE rb_mysql_client_last_id(VALUE self) {
   GET_CLIENT(self);
+  REQUIRE_OPEN_DB(wrapper);
   return ULL2NUM(mysql_insert_id(wrapper->client));
 }
 

spec/mysql2/client_spec.rb

@@ -71,6 +71,9 @@ describe Mysql2::Client do
 
   it "should be able to close properly" do
     @client.close.should be_nil
+    lambda {
+      @client.query "SELECT 1"
+    }.should raise_error(Mysql2::Error)
   end
 
   it "should respond to #query" do
@@ -103,6 +106,13 @@ describe Mysql2::Client do
       }.should raise_error(Mysql2::Error)
     end
 
+    it "should require an open connection" do
+      @client.close
+      lambda {
+        @client.query "SELECT 1"
+      }.should raise_error(Mysql2::Error)
+    end
+
     # XXX this test is not deterministic (because Unix signal handling is not)
     # and may fail on a loaded system
     if RUBY_PLATFORM !~ /mingw|mswin/
@@ -137,27 +147,36 @@ describe Mysql2::Client do
     @client.should respond_to(:escape)
   end
 
-  it "#escape should return a new SQL-escape version of the passed string" do
+  context "#escape" do
+    it "should return a new SQL-escape version of the passed string" do
       @client.escape("abc'def\"ghi\0jkl%mno").should eql("abc\\'def\\\"ghi\\0jkl%mno")
     end
 
-  it "#escape should return the passed string if nothing was escaped" do
+    it "should return the passed string if nothing was escaped" do
       str = "plain"
       @client.escape(str).object_id.should eql(str.object_id)
     end
 
-  it "#escape should not overflow the thread stack" do
+    it "should not overflow the thread stack" do
       lambda {
         Thread.new { @client.escape("'" * 256 * 1024) }.join
       }.should_not raise_error(SystemStackError)
     end
 
-  it "#escape should not overflow the process stack" do
+    it "should not overflow the process stack" do
       lambda {
         Thread.new { @client.escape("'" * 1024 * 1024 * 4) }.join
       }.should_not raise_error(SystemStackError)
     end
 
+    it "should require an open connection" do
+      @client.close
+      lambda {
+        @client.escape ""
+      }.should raise_error(Mysql2::Error)
+    end
+  end
+
   it "should respond to #info" do
     @client.should respond_to(:info)
   end
@@ -203,6 +222,13 @@ describe Mysql2::Client do
     server_info[:version].class.should eql(String)
   end
 
+  it "#server_info should require an open connection" do
+    @client.close
+    lambda {
+      @client.server_info
+    }.should raise_error(Mysql2::Error)
+  end
+
   if defined? Encoding
     context "strings returned by #server_info" do
       it "should default to the connection's encoding if Encoding.default_internal is nil" do
@@ -231,6 +257,13 @@ describe Mysql2::Client do
     @client.socket.should_not eql(0)
   end
 
+  it "#socket should require an open connection" do
+    @client.close
+    lambda {
+      @client.socket
+    }.should raise_error(Mysql2::Error)
+  end
+
   it "should raise a Mysql2::Error exception upon connection failure" do
     lambda {
       bad_client = Mysql2::Client.new :host => "dfjhdi9wrhw", :username => 'asdfasdf8d2h'