Autosave for waveform with 1 element

["Paduan Donadio, Marcio" <marcio@slac.stanford.edu>]

Hello,

here at SLAC, we saw that autosave is failing to recover the data for a waveform with 1 element. For testing purposes, we changed manually NELM to 2 and the recovery succeeded. Another test was to manually edit the sav file, adding the keyword @array@ and the recovering succeeded, too.​

I saw the following comment in 5.4.1 release: "Previously, restoring an array which had been saved with zero or one values failed.  Also, manual restore (including restore by configMenu) of any array PV caused a seg fault.".

As we are using 5.7.1, I think this problem is already corrected since 5.4.1. The behavior was observed when using EPICS 3.15.

The strange thing is that the same version of autosave seems to be working in EPICS 3.14, but not in 3.15.

I saw that autosave uses ca_element_count() from the channel access API. Maybe something changed in this function in EPICS 3.15?

Thank you for your help.

Márcio Paduan Donadio

System Control Engineer - SLAC