Is there a length limitation on file extensions?

[j.o.l]

after some more experiments it looks like I was caught by a looking at
cached data. I was reloading the file for https as it was displayed as text
(happens to be readable xml). However this reload was answered with
not-modified without content-type (which is afaik standard conformant). 
Only on hard reload Chrome got a new copy with content type header. 
Goofish or not, maybe others stumble accross the same problem and this will
help them to resolve the issue.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,265148,265200#msg-265200