ftp://ftp.netbsd.org/pub/pkgsrc/current/pkgsrc/graphics/gif2png/patches/patch-aa

--- gif2png.c
+++ gif2png.c
@@ -10,6 +10,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>	/* for isatty() */
+#include <zlib.h>
 
 #if !defined(TRUE)
 #define FALSE	0
@@ -120,8 +121,8 @@ int writefile(struct GIFelement *s,struc
     int colors_used = 0;
     byte remap[MAXCMSIZE];
     int low_prec;
-    png_struct *png_ptr = xalloc(sizeof (png_struct));
-    png_info *info_ptr = xalloc(sizeof (png_info));
+    png_struct *png_ptr;
+    png_info *info_ptr;
     int p;
     int gray_bitdepth;
     png_color pal_rgb[MAXCMSIZE], *pltep;
@@ -136,6 +137,19 @@ int writefile(struct GIFelement *s,struc
     png_text software;
     png_text comment;
 
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (png_ptr == NULL) {
+      fprintf(stderr, "gif2png: fatal error, out of memory\n");
+      fprintf(stderr, "gif2png: exiting ungracefully\n");
+      exit(1);
+    }
+    info_ptr = png_create_info_struct(png_ptr);
+    if (info_ptr == NULL) {
+      fprintf(stderr, "gif2png: fatal error, out of memory\n");
+      fprintf(stderr, "gif2png: exiting ungracefully\n");
+      exit(1);
+    }
+
     /* these volatile declarations prevent gcc warnings ("variable might be
      *  clobbered by `longjmp' or `vfork'") */
     volatile int gray = TRUE;