check if connection is closed in reset callback

updated .gitignore
updated docs

.gitignore

@@ -2,3 +2,4 @@ npm-debug.log
 node_modules/
 *.sublime-*
 .idea/
+/test.js

README.md

@@ -106,6 +106,9 @@ Release the connect back to the pool to be used again
 
 ## Changelog
 
+### Version 1.0.3
+* bug fix only
+
 ### Version 1.0.3
 * Pool modifies the Tedious connection object rather than the Connection prototype.
 

lib/connection-pool.js

@@ -239,6 +239,9 @@ ConnectionPool.prototype.release = function(connection) {
         if (pooled.con === connection) {
             //reset connection & release it
             connection.reset(function (err) {
+                if (!pooled.con) //the connection failed during the reset
+                    return;
+
                 if (err) { //there is an error, don't reuse the connection, just close it
                     pooled.con.close();
                     return;