pkgCacheFile: Only unlock in destructor if locked before

pkgCacheFile's destructor unlocks the system, which is confusing
if you did not open the cachefile with WithLock set. Create a private
data instance that holds the value of WithLock.

This regression was introduced in commit b2e465d6d32d2dc884f58b94acb7e35f671a87fe:

    Join with aliencode
    Author: jgg
    Date: 2001-02-20 07:03:16 GMT
    Join with aliencode

by replacing a "Lock" member that was only initialized when the lock
was taken by calls to Lock, UnLock; with the latter also taking place
if the former did not occur.

Regression-Of: b2e465d6d32d2dc884f58b94acb7e35f671a87fe
LP: #1794053
(cherry picked from commit e02297b8e22dae04872fe6fab6dba966de65dbba)

0 files changed, 0 insertions, 0 deletions