2nd ptc_twiss crashs when 1st one stops with error

[piotrskowronski]

Dear MAD support,

I found an issue when using PTC_TWISS on a sequence with apertures, I've attached a minimal example.

When the initial conditions are such that the orbit encounters an aperture limit PTC_TWISS seems not to exit in a proper way, and then only when another PTC_TWISS command is given (whether you create a new universe+layout or not) MAD-X exits with

At line 979 of file src/madx_ptc_twiss.f90
Fortran runtime error: Attempting to allocate already allocated variable 'j'

In case this is a known problem, is there a workaround? As far as I'm aware there is no way to exclude the apertures from being imported into PTC, or to ignore apertures during PTC_TWISS, is there?

Best regards,
Linda

[piotrskowronski]

Indeed it is a bug: when ptc_twiss encounters a problem it quits without tiding up the memory. Clearly it needs to be corrected.

[piotrskowronski]

Fixed.