[Magick-bugs] convert fails for pngalpha device using new ghostscript

[duc.sequere.aut.de.via.decede at imagemagick.org]

> ==30776== Invalid free() / delete / delete[]

Unfortunately we cannot reproduce the problem.  We're running 
ImageMagick 6.3.8-2 and Ghostscript 8.60:

-> convert -verbose logo.ps logo.png
"gs" -q -dQUIET -dPARANOIDSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=0 "-sDEVICE=pngalpha" -dTextAlphaBits=4 -dGraphicsAlphaBits=4 "-r72x72" -g640x480  "-sOutputFile=/tmp/magick-XXjkZMgq" "-f/tmp/magick-XXZ3wv1R" "-f/tmp/magick-XXJPzzMj"
/tmp/magick-XXjkZMgq PNG 640x480 640x480+0+0 DirectClass 8-bit 93.6387kb 
logo.ps PS 640x480 640x480+0+0 DirectClass 16-bit 93.6387kb 
logo.ps=>logo.png PS 640x480 640x480+0+0 DirectClass 16-bit 139.055kb