Imported from libpng-0.96.tar
diff --git a/pngrio.c b/pngrio.c
index 96d8290..1a7f038 100644
--- a/pngrio.c
+++ b/pngrio.c
@@ -1,10 +1,11 @@
/* pngrio.c - functions for data input
- libpng 1.0 beta 4 - version 0.90
+ libpng 1.0 beta 6 - version 0.96
For conditions of distribution and use, see copyright notice in png.h
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- January 10, 1997
+ Copyright (c) 1996, 1997 Andreas Dilger
+ May 12, 1997
This file provides a location for all input. Users which need
special handling are expected to write a function which has the same
@@ -20,12 +21,12 @@
reads from a file pointer. Note that this routine sometimes gets called
with very small lengths, so you should implement some kind of simple
buffering if you are using unbuffered reads. This should never be asked
- to read more then 64K on a 16 bit machine. The cast to png_size_t is
- there to quiet some compilers */
+ to read more then 64K on a 16 bit machine. */
void
-png_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
+png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
- if (png_ptr->read_data_fn)
+ png_debug1(4,"reading %d bytes\n", length);
+ if (png_ptr->read_data_fn != NULL)
(*(png_ptr->read_data_fn))(png_ptr, data, length);
else
png_error(png_ptr, "Call to NULL read function");
@@ -37,11 +38,16 @@
than changing the library. */
#ifndef USE_FAR_KEYWORD
static void
-png_default_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
- png_uint_32 check;
+ png_size_t check;
- check = fread(data, 1, (size_t)length, (FILE *)png_ptr->io_ptr);
+ /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+ * instead of an int, which is what fread() actually returns.
+ */
+ check = (png_size_t)fread(data, (png_size_t)1, length,
+ (FILE *)png_ptr->io_ptr);
+
if (check != length)
{
png_error(png_ptr, "Read Error");
@@ -57,9 +63,9 @@
#define MIN(a,b) (a <= b ? a : b)
static void
-png_default_read_data(png_structp png_ptr, png_bytep data, png_uint_32 length)
+png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
- png_uint_32 check;
+ int check;
png_byte *n_data;
FILE *io_ptr;
@@ -68,18 +74,18 @@
io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr);
if ((png_bytep)n_data == data)
{
- check = fread(n_data, 1, (size_t)length, io_ptr);
+ check = fread(n_data, 1, length, io_ptr);
}
else
{
png_byte buf[NEAR_BUF_SIZE];
png_size_t read, remaining, err;
check = 0;
- remaining = (png_size_t)length;
+ remaining = length;
do
{
read = MIN(NEAR_BUF_SIZE, remaining);
- err = fread(buf, 1, read, io_ptr);
+ err = fread(buf, (png_size_t)1, read, io_ptr);
png_memcpy(data, buf, read); /* copy far buffer to near buffer */
if(err != read)
break;
@@ -116,7 +122,7 @@
{
png_ptr->io_ptr = io_ptr;
- if (read_data_fn)
+ if (read_data_fn != NULL)
png_ptr->read_data_fn = read_data_fn;
else
png_ptr->read_data_fn = png_default_read_data;
