Close database/sql connections created through ConnPool

database/sql driver created through stdlib.OpenFromConnPool closes connections
when requested by database/sql rather than release to underlying connection
pool.

CHANGELOG.md

@@ -1,3 +1,9 @@
+# Unreleased
+
+## Fixes
+
+* database/sql driver created through stdlib.OpenFromConnPool closes connections when requested by database/sql rather than release to underlying connection pool.
+
 # 2.11.0 (June 5, 2017)
 
 ## Fixes

stdlib/sql.go

@@ -180,12 +180,12 @@ func (c *Conn) Prepare(query string) (driver.Stmt, error) {
 }
 
 func (c *Conn) Close() error {
+	err := c.conn.Close()
 	if c.pool != nil {
 		c.pool.Release(c.conn)
-		return nil
 	}
 
-	return c.conn.Close()
+	return err
 }
 
 func (c *Conn) Begin() (driver.Tx, error) {