Occasional freeze when registering individual samplers

[Lawrence Deacon]

Program freezes when registering individual samplers e.g. in examples/features/processes/6_muon/muon_samplers.gmad.

There are no problems registering all components as samplers using:

sample, all;

[Jochem Snuverink]

Thanks for the report. This happens only if the sampler is attached to the first element and if that is a marker.

[Jochem Snuverink]

This was due to a bug in the fastlist class implementation. Some range iterators were invalidated while inserting into the lookup map. Surprisingly this didn't show up more often.

[Jochem Snuverink]

fix issue #113 : careful insertion into lookup map

→ <<cset be3265b38e28>>