SHP provider: spatial index out of date is not recreated

[danstoica]

The issue occurs when a 3rd party application is editing the SHP file. Note the spatial index IDX file is FDO specific and it will not be updated. Thus it is getting stale.

A solution is checking the timestamps of the SHP and IDX files. If the SHP file has been edited since the last IDX file change, that would indicate a 3rd party edit to that SHP file. It is a valid solution to this problem since the IDX create/recreate/update is based on reading the current SHP records. Thus the timestamps will reflect the sequence of operations.

The C++ function to get the filestamp is stat() which can retrieve the last modified date. It is available both on Windows and Linux.