Patch for Go issue 4459

[gwenn]

Hello,
A patch can be applied to go-sqlite3 to fix issue 4459 (https://code.google.com/p/go/issues/detail?id=4459):

diff --git a/sqlite3.go b/sqlite3.go
index 0a21d23..6070617 100644
--- a/sqlite3.go
+++ b/sqlite3.go
@@ -136,7 +136,7 @@ func (c *SQLiteConn) Close() error {
        }
        rv := C.sqlite3_close(c.db)
        if rv != C.SQLITE_OK {
-               return errors.New("sqlite succeeded without returning a database")
+               return errors.New("error while closing sqlite database connection")
        }
        c.db = nil
        return nil
@@ -170,6 +170,9 @@ func (s *SQLiteStmt) Close() error {
                return nil
        }
        s.closed = true
+       if s.c == nil || s.c.db == nil {
+               return errors.New("sqlite statement with already closed database connection")
+       }
        rv := C.sqlite3_finalize(s.s)
        if rv != C.SQLITE_OK {
                return errors.New(C.GoString(C.sqlite3_errmsg(s.c.db)))

The error messages may be improved...
Regards