Re: [perl #36616] bug or feature? foreach (sort @array) {y/a-z/A-Z/;} # @array modified!

[Adriano Ferreira]

The described behavior changes whether "sort @arr" goes directly in
'for' or you assign it first to an array variable.

   @arr = ('one', 'two', 'three', 'four');
   y/a-z/A-Z/ foreach sort @arr;
   print "\na: @arr\n"

prints "a: ONE TWO THREE FOUR" and

   @arr = ('one', 'two', 'three', 'four');
   @s = sort @arr;
   y/a-z/A-Z/ foreach @s;
   print "\na: @arr\n"

prints "a: one two three four". This has to do with copy-on-assign?

That seems like a (subtle) feature. Otherwise, it is a very old bug:
the same behavior with 5.8.6, 5.6.1, and  5.005_03.