Imported from libpng-1.4.0beta51.tarv1.4.0beta51

1 files changed, 6 insertions, 4 deletions

diff --git a/pngwio.c b/pngwio.c
index 535a15d40..29cb01067 100644
--- a/pngwio.c
+++ b/pngwio.c
@@ -1,7 +1,7 @@
 
 /* pngwio.c - functions for data output
  *
- * Last changed in libpng 1.4.0 [March 9, 2009]
+ * Last changed in libpng 1.4.0 [March 21, 2009]
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -119,8 +119,7 @@ png_default_flush(png_structp png_ptr)
    png_FILE_p io_ptr;
    if (png_ptr == NULL) return;
    io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
-   if (io_ptr != NULL && png_fileno(io_ptr) != -1)
-      fflush(io_ptr);
+   fflush(io_ptr);
 }
 #endif
 #endif
@@ -149,7 +148,10 @@ png_default_flush(png_structp png_ptr)
                    PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
                    time, output_flush_fn will be ignored, although it must be
                    supplied for compatibility.  May be NULL, in which case
-                   libpng's default function will be used. */
+                   libpng's default function will be used, if
+                   PNG_WRITE_FLUSH_SUPPORTED is defined.  This is not
+                   a good idea if io_ptr does not point to a standard
+                   *FILE structure. */
 void PNGAPI
 png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)