libtiff: Fix unsigned vs signed comparison warning.

third_party/libtiff/tif_pixarlog.c

 /* $Id: tif_pixarlog.c,v 1.39 2012-12-10 17:27:13 tgl Exp $ */
 
 /*
  * Copyright (c) 1996-1997 Sam Leffler
  * Copyright (c) 1996 Pixar
  *
  * Permission to use, copy, modify, distribute, and sell this software and 
  * its documentation for any purpose is hereby granted without fee, provided
  * that (i) the above copyright notices and this permission notice appear in
  * all copies of the software and related documentation, and (ii) the names of
@@ skipping 766 matching lines @@
             we need to simplify this code to reflect a ZLib that is likely updated
             to deal with 8byte memory sizes, though this code will respond
             apropriately even before we simplify it */
         sp->stream.avail_out = (uInt) (nsamples * sizeof(uint16));
         if (sp->stream.avail_out != nsamples * sizeof(uint16))
         {
                 TIFFErrorExt(tif->tif_clientdata, module, "ZLib cannot deal with buffers this size");
                 return (0);
         }
         /* Check that we will not fill more than what was allocated */
-        if (sp->stream.avail_out > sp->tbuf_size)
+        if ((tmsize_t)sp->stream.avail_out > sp->tbuf_size)
         {
                 TIFFErrorExt(tif->tif_clientdata, module, "sp->stream.avail_out > sp->tbuf_size");
                 return (0);
         }
         do {
                 int state = inflate(&sp->stream, Z_PARTIAL_FLUSH);
                 if (state == Z_STREAM_END) {
                         break;                  /* XXX */
                 }
                 if (state == Z_DATA_ERROR) {
@@ skipping 643 matching lines @@
 #endif /* PIXARLOG_SUPPORT */
 
 /* vim: set ts=8 sts=8 sw=8 noet: */
 /*
  * Local Variables:
  * mode: c
  * c-basic-offset: 8
  * fill-column: 78
  * End:
  */