Imported from libpng-1.2.0beta5.tar
diff --git a/pngwutil.c b/pngwutil.c
index 841fcc2..68bb9a4 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -1,7 +1,7 @@
/* pngwutil.c - utilities to write a PNG file
*
- * libpng 1.2.0beta4 - June 23, 2001
+ * libpng 1.2.0beta5 - August 8, 2001
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2001 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
@@ -996,6 +996,12 @@
else if (color_type == PNG_COLOR_TYPE_GRAY)
{
/* one 16 bit value */
+ if(tran->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
+ return;
+ }
png_save_uint_16(buf, tran->gray);
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
}
@@ -1005,6 +1011,12 @@
png_save_uint_16(buf, tran->red);
png_save_uint_16(buf + 2, tran->green);
png_save_uint_16(buf + 4, tran->blue);
+ if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
+ return;
+ }
png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
}
else
@@ -1045,10 +1057,22 @@
png_save_uint_16(buf, back->red);
png_save_uint_16(buf + 2, back->green);
png_save_uint_16(buf + 4, back->blue);
+ if(png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
+ return;
+ }
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
}
else
{
+ if(back->gray >= (1 << png_ptr->bit_depth))
+ {
+ png_warning(png_ptr,
+ "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
+ return;
+ }
png_save_uint_16(buf, back->gray);
png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
}