Reply To cazfi
It's likely that a more serious bug than tiny memory leak lurks there - certainly it was not created to be registered to no action.
It's used in S3_1, for ACTRES_BOMBARD. It's no longer an obligatory bombard requirement in master. The oblig_hard_req_reg() call just wasn't removed when the only action previously registered to it stopped being registered to it.
Originally detected by valgrind as a memory leak: One of the oblig_hard_req_reg() calls has no target action results (list is immediately terminated by ACTRES_NONE). With zero users to begin with, nobody reduces its reference count and thus code to free it is never triggered.
It's likely that a more serious bug than tiny memory leak lurks there - certainly it was not created to be registered to no action.
It's the one about war with tile owner OR tile having no city.