PATCH: [perl #133347] Tk broken

PATCH: [perl #133347] Tk broken

This was caused by utf8_to_uvchr() failing to set the returned ptr
in some circumstances, leading to reading uninitialized memory.

A test failure remains, and I'll wait for Slaven's feedback before
looking further into that.  It is in t/photo.t

 couldn't recognize image data at blib/lib/Tk/Image.pm line 21.
 # Looks like your test exited with 255 just after 100

And it's trying at that point to look at 'Xcamel.gif'