Fix for CVE CVE-2016-10167

DOS vulnerability in gdImageCreateFromGd2Ctx()

Change based on commit at:

https://github.com/libgd/libgd/commit/fe9ed49dafa993e3af96b6a5a589efeea9bfb36f

--- gd_gd2.c.orig	2017-01-31 07:09:38.043472825 +0000

+++ gd_gd2.c	2017-01-31 07:40:06.395740258 +0000

@@ -414,10 +414,9 @@

 			{

 			  if (!gdGetInt (&im->tpixels[y][x], in))

 			    {

-			      /*printf("EOF while reading\n"); */

-			      /*gdImageDestroy(im); */

-			      /*return 0; */

-			      im->tpixels[y][x] = 0;

+			      fprintf (stderr, "gd2: EOF while reading\n");

+			      gdImageDestroy(im);

+			      return NULL;

 			    }

 			}

 		      else

@@ -425,10 +424,9 @@

 			  int ch;

 			  if (!gdGetByte (&ch, in))

 			    {

-			      /*printf("EOF while reading\n"); */

-			      /*gdImageDestroy(im); */

-			      /*return 0; */

-			      ch = 0;

+			      fprintf (stderr, "gd2: EOF while reading\n");

+			      gdImageDestroy(im);

+			      return NULL;

 			    }

 			  im->pixels[y][x] = ch;

 			}