Silly me, I upgraded my development Mac to Snow Leopard, and a bunch of my UTF-8 code broke with the newer version of Perl (5.10.0). I've isolated the problem to a strange behavior with regular expressions, have RT'ed the FM, and can't find an explanation in any of the expected behaviors of newer Perl. Thinking this might be a bug, I've rolled forward to 5.12.0/1, but the problem persists. I could try to roll back to the older (5.6?) Perl, but would prefer to understand what's going on, and fix my code, if possible.

Here's a simple test case. The string in question is valid UTF-8 as far as I can tell (same problem persists when reading from a UTF-8 file), and works with most regular expressions, just not a very specific combination of them. 

#!/usr/bin/perl

use strict vars;
use utf8;
use encoding 'utf8';

my $e = "Böck";

if (utf8::is_utf8($e)) { print "yep, is UTF8\n"; }

# this fails with: Malformed UTF-8 character
# seems to require the combination of a minimum-length wildcard match
# + non-matching character class. For example:
#       m/.*?[k]$/      succeeds
#       m/.*?x$/      succeeds
#       m/.*[x]$/      succeeds

if ($e=~ m/.*?[x]$/) { print "matched\n"; }

print "success with $e\n";

[download]
The program dies thus: 
% ./test.pl
yep, is UTF8
Malformed UTF-8 character (fatal) at ./test.pl line 17.

[download]

Have tried lots of things, to no avail. Perhaps some monk more adept than I will have a clue as to how to approach this?

Many thanks!

In reply to Odd problems with UTF-8, regexps, and newer Perl versions by ablegrape

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