Re: [png-mng-implement] png_get_uint_16 should return the type png_uint_16

[<jb...@ac...>]

Yes, that's the right place for it too - this is where anyone who gets compiler warnings as a result will look.

John Bowler <jb...@ac...>

-----Original Message-----
From: Glenn Randers-Pehrson [mailto:gl...@gm...] 
Sent: Wednesday, November 24, 2010 12:12 PM
To: jb...@ac...; PNG/MNG implementation discussion list
Subject: Re: [png-mng-implement] png_get_uint_16 should return the type png_uint_16

Is this about right to put in libpng-1.4.5/png.h?

  /* The following definition introduces an API incompatibility (but not
   * an ABI incompatibility) with libpng-1.4.0 through 1.4.4.  Prior to
   * libpng-1.4.5 the macro, which is used by default, returned (incorrectly)
   * a (png_uint_32), while the function, if used instead, correctly returned
   * a (png_uint_16).
   *
   * Libpng versions 1.0.x and 1.2.x only used functions so are not affected
   * by this potential API incompatibility among macros.
   */
#  define png_get_uint_16(buf) \
     ((png_uint_16) \
       (((unsigned int)(*(buf)) << 8) + \
        ((unsigned int)(*((buf) + 1)))))

Glenn