[Python-Dev] Commit messages: please avoid temporal ambiguity

[Terry Reedy]

A commit (push) partition time and behavior into before and after (with 
a short change period in between during which behavior is undefined).

Some commit messages have the form 'x does y'. Does 'does' mean before 
or after? Sometimes that is clear. 'x crashes' means before. 'x return 
correct value' means after. But some messages of this type are unclear 
to me as written.

Consider 'x raises exception'? The temporal reference is obvious to the 
committer but not necessary to everyone else. It could mean 'x used to 
segfault and now raises a catchable exception'. There was a fix like 
this (with a clear message) just today. It could also mean 'x used to 
raise but now return an answer. There have been many fixes like this.

Two minimal fixes are 'x raised exception' or 'make x raise exception'.

-- 
Terry Jan Reedy