[magick-users] Backslashes and percentage signs in image comments

[Anthony Thyssen]

Felix Hagemann on  wrote...
| Hello,
| I try to add image comments that contain backslashes and/or percentage
| signs but I am not having much success. Consider the following
| example:
| 
| $ convert -comment 'test\123\456\n%%w' logo: png:- | identify \
| -format '%c' png:-
| 
| Its output for ImageMagick 6.2.3 and some earlier versions, which were
| available for testing:
| 
| test\123\456
| 640
| 
| For ImageMagick 6.2.4:
| 
| test1346
| 641
| 
VERIFIED as FAILING on the latest beta...  IM v6.3.2-6  Feb 14 23:??

The escaping of escapes is failing!

=======8<--------
convert -version
Version: ImageMagick 6.3.2 02/15/07 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2007 ImageMagick Studio LLC

convert -comment 'test\\123\\456\\n%%w' logo: png:- |\
  identify -format '%c' png:-
test123456
640
=======8<--------

That last should have returned the exact string...
test\123\456\n%w

this is also failing with label...

=======8<--------
convert -label 'test\\123\\456\\n%%w' logo: png:- |\
   identify -format '%l' png:-
test123456
640
=======8<--------

Trying this with the -set operator method, also fails..

=======8<--------
convert logo: -set comment 'test\\123\\456\\n%%w' png:- |\
   identify -format '%c' png:-
test123456
640

convert logo: -set label 'test\\123\\456\\n%%w' png:- |\
  identify -format '%l' png:-
test123456
640
=======8<--------



Continuing escape escaping with labels....

=======8<--------
convert -comment 'test' label:'test\\123\\456\\n%%c' x:
=======8<--------
Image reads...
=======8<--------
test\123\456
%c
=======8<--------

Which is correct for most things, but WRONG for the newline character

Without the escaped escapes however...
=======8<--------
convert -comment 'test' label:'test\123\456\n%c' x:
=======8<--------
Image reads
=======8<--------
test123456
test
=======8<--------
And that is CORRECT.


ASIDE: You can escape the special meaning of a '@' at the start of a
line with backslash, and that is working.  Though the '@' special
meaning does not work for label or comment settings....

=======8<--------
echo "stdin" | convert label:'\@-' x:
=======8<--------

  Anthony Thyssen ( System Programmer )    <A.Thyssen at griffith.edu.au>
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    Shh!  Be vewy vewy qwiwet.  I'm hunting dose peskwey wuntime ewwors.
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     Anthony's Home is his Castle     http://www.cit.gu.edu.au/~anthony/