From: Glenn Randers-Pehrson <glennrp@gmail.com>
Date: Tue, 12 Sep 2017 23:35:34 +0000 (-0400)
Subject: Max valid hour is 23, not 24 in PNG tIME chunk
X-Git-Tag: 7.0.7-3~60
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ce14a33e93e04c11f816e88185aca2c5e3949244;p=imagemagick

Max valid hour is 23, not 24 in PNG tIME chunk
---

diff --git a/coders/png.c b/coders/png.c
index 0c47fe6d2..e4c15fbd8 100644
--- a/coders/png.c
+++ b/coders/png.c
@@ -8174,6 +8174,7 @@ static void write_tIME_chunk(Image *image,png_struct *ping,png_info *info,
   if (addhours < 0)
   {
     addhours+=24;
+    addminutes=-addminutes;
     day--;
   }
   hour+=addhours;
@@ -8202,7 +8203,7 @@ static void write_tIME_chunk(Image *image,png_struct *ping,png_info *info,
      hour++;
      minute-=60;
   }
-  if (hour > 24)
+  if (hour > 23)
   {
      day ++;
      hour -=24;