buffer-overflow-in-real-program

cpTags(TIFF* in, TIFF* out)
 {
     struct cpTag *p;
     for (p = tags; p < &tags[NTAGS]; p++)
-   cpTag(in, out, p->tag, p->count, p->type);
+   {
+       if( p->tag == TIFFTAG_GROUP3OPTIONS )
+       {
+           uint16 compression;
+           if( !TIFFGetField(in, TIFFTAG_COMPRESSION, &compression) ||
+               compression != COMPRESSION_CCITTFAX3 )
+               continue;
+       }
+       if( p->tag == TIFFTAG_GROUP4OPTIONS )
+       {
+           uint16 compression;
+           if( !TIFFGetField(in, TIFFTAG_COMPRESSION, &compression) ||
+               compression != COMPRESSION_CCITTFAX4 )
+               continue;
+       }
+       cpTag(in, out, p->tag, p->count, p->type);
+   }
 }