Add an optimization case to _get_prev_page that avoids a redundant seek/resync/reread in the common seek case.
Add an optimization case to _get_prev_page that avoids a redundant seek/resync/reread in the common seek case.



git-svn-id: 03f0f1727258f1959b7b485b30a676bafdb78148@15925 0101bb08-14d6-0310-b084-bc0e0c8e3800

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