Re: Strange results from lwarn + match-string

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>> (lwarn t :warning "0: %s" (match-string-no-properties 0))
>>> (lwarn t :warning "1: %s" (match-string-no-properties 1))
>>> (lwarn t :warning "2: %s" (match-string-no-properties 2))
>>> (lwarn t :warning "3: %s" (match-string-no-properties 3))
>> 
>> Since you don't know for a fact that lwarn is among the few functions
>> that do not affect match-data, you need to call all
>> 4 `match-string-no-properties' before you call the 4 `lwarn'.

> Hm. It cured the problem, but that was really a surprise.

There are very few functions which guarantee that they preserve
match-data, so if there's the slightest doubt, assume that match-data
will be destroyed,


        Stefan