Source: https://sources.debian.net/src/tvtime/1.0.2-14/debian/patches/libpng.diff

From: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Date: Mon, 14 May 2012 19:01:31 +0900
Prepares the package for libpng 1.5.  Closes: #650582.

--- tvtime-1.0.2.orig/src/pngoutput.c
+++ tvtime-1.0.2/src/pngoutput.c
@@ -18,5 +18,6 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <zlib.h>
 #include <png.h>
 #include "pngoutput.h"