DB_TMP_DIR

This change only affects Win/32 applications that create in-memory databases.

On Win/32 platforms an additional test has been added when searching for the appropriate directory in which to create the temporary files that are used to back in-memory databases. Berkeley DB now uses any return value from the GetTempPath interface as the temporary file directory name before resorting to the static list of compiled-in pathnames.

If the system registry does not return the same directory as Berkeley DB has been using previously, this change could cause temporary backing files to move to a new directory when applications are upgraded to the 3.1 release. In extreme cases, this could create (or fix) security problems if the file protection modes for the system registry directory are different from those on the directory previously used by Berkeley DB.