[Gimp-developer] incompatible pointer type in file-png.c in load_color_profile?

[Elle Stone <ellestone ninedegreesbelow com>]

While compiling GIMP I noticed the following warning, and was wondering 
if this warning is completely harmless:

file-png.c: In function 'load_color_profile':
file-png.c:800:53: warning: passing argument 5 of 'png_get_iCCP' from 
incompatible pointer type
   if (png_get_iCCP (pp, info, &profname, &profcomp, &prof, &proflen))
                                                     ^
In file included from /usr/include/libpng16/png.h:340:0,
                 from file-png.c:51:
/usr/include/libpng16/png.h:2086:30: note: expected 'png_bytepp' but 
argument is of type 'char **'
 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
                              ^
/usr/include/libpng16/pngconf.h:287:70: note: in definition of macro 
'PNG_FUNCTION'
 #  define PNG_FUNCTION(type, name, args, attributes) attributes type 
name args
                                                                      ^
/usr/include/libpng16/pngconf.h:311:4: note: in expansion of macro 
'PNG_EXPORTA'
    PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
    ^
/usr/include/libpng16/png.h:2086:1: note: in expansion of macro 'PNG_EXPORT'
 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
 ^
file-png.c: In function 'save_image':
file-png.c:1692:23: warning: pointer targets in passing argument 5 of 
'png_set_iCCP' differ in signedness [-Wpointer-sign]
                       (png_charp) icc_data,
                       ^
In file included from /usr/include/libpng16/png.h:340:0,
                 from file-png.c:51:
/usr/include/libpng16/png.h:2092:23: note: expected 'png_const_bytep' 
but argument is of type 'char *'
 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
                       ^
/usr/include/libpng16/pngconf.h:287:70: note: in definition of macro 
'PNG_FUNCTION'
 #  define PNG_FUNCTION(type, name, args, attributes) attributes type 
name args
                                                                      ^
/usr/include/libpng16/pngconf.h:311:4: note: in expansion of macro 
'PNG_EXPORTA'
    PNG_EXPORTA(ordinal, type, name, args, PNG_EMPTY)
    ^
/usr/include/libpng16/png.h:2092:1: note: in expansion of macro 'PNG_EXPORT'
 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
 ^
  CCLD   file-png


Elle