/* pngget.c - retrieval of values from info struct
*
- * Copyright (c) 2018 Cosmin Truta
+ * Copyright (c) 2018-2023 Cosmin Truta
* Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
* Copyright (c) 1996-1997 Andreas Dilger
* Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
png_uint_32 flag)
{
if (png_ptr != NULL && info_ptr != NULL)
+ {
+#ifdef PNG_READ_tRNS_SUPPORTED
+ /* png_handle_PLTE() may have canceled a valid tRNS chunk but left the
+ * 'valid' flag for the detection of duplicate chunks. Do not report a
+ * valid tRNS chunk in this case.
+ */
+ if (flag == PNG_INFO_tRNS && png_ptr->num_trans == 0)
+ return(0);
+#endif
+
return(info_ptr->valid & flag);
+ }
return(0);
}