created according to:   https://github.com/libgd/libgd/commit/aba3db8

                        https://github.com/libgd/libgd/commit/a6a0e7feabb2a9738086a5dc96348f233c87fa79

                        https://github.com/libgd/libgd/commit/48bbc25

diff -urN '--exclude=cscope.*' gd-2.0.35/gd_gd2.c fixed/gd_gd2.c

--- gd-2.0.35/gd_gd2.c	2007-01-04 13:40:48.000000000 +0100

+++ fixed/gd_gd2.c	2020-11-04 08:46:03.800937688 +0100

@@ -169,11 +169,17 @@

     {

       nc = (*ncx) * (*ncy);

       GD2_DBG (printf ("Reading %d chunk index entries\n", nc));

+      if (overflow2(sizeof(t_chunk_info), nc)) {

+		goto fail1;

+      }

       sidx = sizeof (t_chunk_info) * nc;

+      if (sidx <=0) {

+		goto fail1;

+      }

       cidx = gdCalloc (sidx, 1);

-			if (!cidx) {

-				goto fail1;

-			}

+      if (cidx == NULL) {

+		goto fail1;

+      }

       for (i = 0; i < nc; i++)

 	{

 	  if (gdGetInt (&cidx[i].offset, in) != 1)