commit 310a252fb63b259c8a5730c1dfe4d387997a53e1
author Sameer Agarwal <sameeragarwal@google.com> Fri Aug 04 18:30:52 2023 -0700
committer Sameer Agarwal <sameeragarwal@google.com> Fri Aug 04 18:35:25 2023 -0700
tree 1d11c843d71195b53a0e6d64802ca5e06cf58b43
parent 357482db701a85f101784a99159d063c5c3fa192

Deal with infinite initial cost correctly.

Previously it could be the case that a residual block could return
a residual whose squared norm overflows and generates an infinity
which we did not detect. This would then lead to the trust region
minimizer incorrectly terminating indicating convergence while
generating a cost delta of NaN.

This change adds a check for that and also does two minor cosmetic
changes.

1. Reduce the level of nesting in program_evaluator.h by adding
   an early return.
2. The error message when IterationZero fails now says that the
   Initial residual and Jacobian failed, to indicate that the
   optimizer had no chance to do any work.

Fixes https://github.com/ceres-solver/ceres-solver/issues/988

Thanks to @Ashray-g for reporting this.

Change-Id: I52ae7627a66f637135209dbb2e42935b52c8bc77