From 4d6b920cfea41467a1179e8a53a66b3d6f8438dc Mon Sep 17 00:00:00 2001
From: Dirk Lemstra <dirk@lemstra.org>
Date: Thu, 25 Apr 2024 12:34:59 +0200
Subject: [PATCH] Added version checks for itxt_length in the png coder.

---
 coders/png.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/coders/png.c b/coders/png.c
index 5baa7d48d..19dfd3ab8 100644
--- a/coders/png.c
+++ b/coders/png.c
@@ -8258,22 +8258,25 @@ static void Magick_png_set_text(png_struct *ping,png_info *ping_info,
   MngInfo *mng_info,const ImageInfo *image_info,const char *key,
   const char *value)
 {
+#if PNG_LIBPNG_VER >= 10600
   const char
     *c;
 
+  MagickBooleanType
+    write_itxt=MagickFalse;
+#endif
+
   int
     compresion_none = PNG_TEXT_COMPRESSION_NONE,
     compresion_zTXt = PNG_TEXT_COMPRESSION_zTXt;
 
-  MagickBooleanType
-    write_itxt=MagickFalse;
-
   png_textp
     text;
 
   size_t
     length;
 
+#if PNG_LIBPNG_VER >= 10600
   /*
     Check if the string contains non-Latin1 characters.
   */
@@ -8288,6 +8291,7 @@ static void Magick_png_set_text(png_struct *ping,png_info *ping_info,
     }
     c++;
   }
+#endif
 #if PNG_LIBPNG_VER >= 10400
   text=(png_textp) png_malloc(ping,(png_alloc_size_t) sizeof(png_text));
 #else
@@ -8299,10 +8303,12 @@ static void Magick_png_set_text(png_struct *ping,png_info *ping_info,
   text[0].key=(char *) key;
   text[0].text=(char *) value;
   length=strlen(value);
-  if (write_itxt == MagickFalse)
-    text[0].text_length=length;
-  else
+#if PNG_LIBPNG_VER >= 10600
+  if (write_itxt != MagickFalse)
     text[0].itxt_length=length;
+  else
+#endif
+    text[0].text_length=length;
   if (mng_info->ping_exclude_tEXt != MagickFalse)
     text[0].compression=compresion_zTXt;
   else