I'm going to jump in with my comments...
For any repair already created a problem
, but I guess I know what you mean...
I used to build woodies from scratch, and I done quite a bit of woodworking so I guess that you are thinking with a woodie, if breaks, just cut/splice/ sand, cover/ done.
Lately I'm more into composites and you need to have other aproach for them, but the principle is almost the same (a bit more messy and sticky until you yet the yist of it).
I just repaired a fully molde wing using a combination of techniques
I guess the answer to you question is depends on the type of damage but, the procedure would be pretty similar as if was wood, clear enough of the spar to be able to splice it.
I think composite repairing is pretty much the same as in wood (may be even easier) it just requires a different set of tools/materials and a slightly different approach but not much.