File htmldoc-CVE-2022-24191.patch of Package htmldoc.17472

commit fb0334a51300988e9b83b9870d4063e86002b077
Author: Michael R Sweet <michael.r.sweet@gmail.com>
Date:   Tue Jan 25 18:11:34 2022 -0500

    Fix a potential stack overflow bug with GIF images (Issue #470)

diff --git a/htmldoc/image.cxx b/htmldoc/image.cxx
index a483784..550b0f9 100644
--- a/htmldoc/image.cxx
+++ b/htmldoc/image.cxx
@@ -465,7 +465,6 @@ gif_read_lzw(FILE *fp,			/* I - File to read from */
     {
       uchar	buf[260];
 
-
       if (!gif_eof)
         while (gif_get_block(fp, buf) > 0);
 
@@ -482,17 +481,23 @@ gif_read_lzw(FILE *fp,			/* I - File to read from */
 
     while (code >= clear_code)
     {
+      if (sp >= (stack + sizeof(stack)))
+        return (255);
+
       *sp++ = table[1][code];
+
       if (code == table[0][code])
 	return (255);
 
       code = table[0][code];
     }
 
+    if (sp >= (stack + sizeof(stack)))
+      return (255);
+
     *sp++ = firstcode = table[1][code];
-    code  = max_code;
 
-    if (code < 4096)
+    if ((code = max_code) < 4096)
     {
       table[0][code] = oldcode;
       table[1][code] = firstcode;