old_contents: class LibPngPackage (Package):
  	def __init__ (self):
  		Package.__init__(self, 'libpng', '1.4.12',
  										 sources = ['http://downloads.sourceforge.net/sourceforge/libpng/libpng-1.4.12.tar.xz'],
  										 configure_flags = ['--enable-shared'])
  
  		#This package would like to be built with fat binaries
  		if Package.profile.m64 == True:
  			self.fat_build = True
  
  LibPngPackage()
  
new_contents: class LibPngPackage (SourceForgeXzPackage):
  	def __init__ (self):
  		SourceForgeXzPackage.__init__ (self, 'libpng', 'libpng', '1.6.17', configure_flags = ['--enable-shared'])
  
  		# If we are on OS X this package likes to be a fat binary
  		if Package.profile.name == 'darwin':
  			if Package.profile.m64 == True:
  				self.fat_build = True
  
  LibPngPackage()
subject: Update libpng to 1.6.17