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