Do not remove connections with non-fatal errors from the pool

Author: dougwilson

Changes.md

@@ -7,6 +7,7 @@ you spot any mistakes.
 ## HEAD
 
 * Delay implied connect until after `.query` argument validation
+* Do not remove connections with non-fatal errors from the pool
 * Error early if `callback` argument to `.query` is not a function #1060
 * Lazy-load modules from many entry point; reduced memory use
 

lib/PoolConnection.js

@@ -14,7 +14,11 @@ function PoolConnection(pool, options) {
   // the connection to end as well, thus we only need to watch for the end event
   // and we will be notified of disconnects.
   this.on('end', this._removeFromPool);
-  this.on('error', this._removeFromPool);
+  this.on('error', function (err) {
+    if (err.fatal) {
+      this._removeFromPool();
+    }
+  });
 }
 
 PoolConnection.prototype.changeUser = function changeUser(options, callback) {

test/unit/pool/test-query-error.js

@@ -0,0 +1,31 @@
+var assert = require('assert');
+var common = require('../../common');
+var pool   = common.createPool({
+  connectionLimit    : 1,
+  port               : common.fakeServerPort,
+  waitForConnections : false
+});
+
+var server = common.createFakeServer();
+
+server.listen(common.fakeServerPort, function (err) {
+  assert.ifError(err);
+
+  pool.getConnection(function (err, conn) {
+    assert.ifError(err);
+
+    conn.query('SELECT INVALID');
+    conn.on('error', function () {
+      pool.getConnection(function (err) {
+        assert.ok(err);
+        assert.equal(err.message, 'No connections available.');
+
+        conn.release();
+        pool.end(function (err) {
+          assert.ifError(err);
+          server.destroy();
+        });
+      });
+    });
+  });
+});