UBSAN failures

[armintoepfer]

Next round of sanitizer failures that I'd appreciate getting fixed so we can finally have a UBSAN passing CI run of pbmm2 ;)

minimap2/chain.c:158:2: runtime error: null pointer passed as argument 2, which is declared to never be null
minimap2/chain.c:159:2: runtime error: null pointer passed as argument 1, which is declared to never be null

I'm using tag v2.17.

[lh3]

This is probably because minimap2 is memcpy-ing zero-length memory blocks. It should harmless and can probably by fixed by a check on the block length. I will come back to this later.

[lh3]

Could you check if d90583b fixes the issue? Thanks!

[armintoepfer]

Works! Thank you.