Imported from libpng-1.0.1e.tar
diff --git a/pngrio.c b/pngrio.c
index a17c64d..b57b563 100644
--- a/pngrio.c
+++ b/pngrio.c
@@ -1,12 +1,11 @@
/* pngrio.c - functions for data input
*
- * libpng 1.0.1d
+ * libpng 1.0.1e - June 6, 1998
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
*
* This file provides a location for all input. Users who need
* special handling are expected to write a function that has the same
@@ -136,7 +135,14 @@
#endif
/* It is an error to write to a read device */
- png_ptr->write_data_fn = NULL;
+ if (png_ptr->write_data_fn != NULL)
+ {
+ png_ptr->write_data_fn = NULL;
+ png_warning(png_ptr,
+ "It's an error to set both read_data_fn and write_data_fn in the ");
+ png_warning(png_ptr,
+ "same structure. Resetting write_data_fn to NULL.");
+ }
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
png_ptr->output_flush_fn = NULL;