Percent signs in ghostscript output files should be duplicated

[Pavel Roskin]

Percent signs in ghostscript output files (i.e. those after  
-sOutputFile) should be duplicated on the command line.  It's not a  
format string bug as I initially suspected, it's a documented feature.

http://ghostscript.com/doc/8.63/Use.htm#File_output

"Note: Since the % character is used to precede the page number format  
specification, in order to represent a file name that contains a %,  
double % characters must be used. For example for the file my%foo the  
OutputFile string needs to be my%%foo."

As it stands now, lilypond generates a postscript file but fails to  
produce a pdf if the original filename contains a percent sign.

$ lilypond Mazurek\ D%85browskiego.ly
GNU LilyPond 2.17.21
Processing `Mazurek D%85browskiego.ly'
Parsing...
Interpreting music...
Interpreting music...[8][16]
Preprocessing graphical objects...
MIDI output to `Mazurek D%85browskiego.midi'...
Fitting music on 1 page...
Drawing systems...
Layout output to `Mazurek D%85browskiego.ps'...
Converting to `./Mazurek D%85browskiego.pdf'...
warning: `(gs -q -dSAFER -dDEVICEWIDTHPOINTS=595.28  
-dDEVICEHEIGHTPOINTS=841.89 -dCompatibilityLevel=1.4 -dNOPAUSE -dBATCH  
-r1200 -sDEVICE=pdfwrite -sOutputFile=./Mazurek D%85browskiego.pdf  
-c.setpdfwrite -fMazurek D%85browskiego.ps)' failed (256)

fatal error: failed files: "Mazurek D%85browskiego.ly"

Percent signs in the input files (after -f) should not be duplicated.

--
Regards,
Pavel Roskin