UTF-8 in package names and sub names? The first is problematic
because of the mapping to pathnames, ditto for the second one if
-one does autosplitting, for example.
+one does autosplitting, for example. Some of this works already
+in 5.8.0, but essentially it is unsupported. Constructs to consider,
+at the very least:
+
+ use utf8;
+ package UnicodePackage;
+ sub new { bless {}, shift };
+ sub UnicodeMethod1 { ... $_[0]->UnicodeMethod2(...) ... }
+ sub UnicodeMethod2 { ... } # in here caller(0) should contain Unicode
+ ...
+ package main;
+ my $x = UnicodePackage->new;
+ print ref $x, "\n"; # should be Unicode
+ $x->UnicodeMethod1(...);
+ my $y = UnicodeMethod3 UnicodePackage ...;
+
+In the above all I<UnicodeXxx> contain (identifier-worthy) characters
+beyond the code point 255, for example 256. Wherever package/class or
+subroutine names can be returned needs to be checked for Unicodeness.
=back
=head2 Unicode in Filenames
-chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open, qx,
-readdir, readlink, rename, rmdir, stat, symlink, sysopen, system,
-truncate, unlink, utime. All these could potentially accept Unicode
-filenames either as input or output (and in the case of system and qx
-Unicode in general, as input or output to/from the shell). Whether a
-filesystem - an operating system pair understands Unicode in filenames
-varies.
+chdir, chmod, chown, chroot, exec, glob, link, lstat, mkdir, open,
+opendir, qx, readdir, readlink, rename, rmdir, stat, symlink, sysopen,
+system, truncate, unlink, utime. All these could potentially accept
+Unicode filenames either as input or output (and in the case of system
+and qx Unicode in general, as input or output to/from the shell).
+Whether a filesystem - an operating system pair understands Unicode in
+filenames varies.
Known combinations that have some level of understanding include
Microsoft NTFS, Apple HFS+ (In Mac OS 9 and X) and Apple UFS (in Mac