Imported from libpng-0.85.tar
diff --git a/pngwrite.c b/pngwrite.c
index 50ea96b..453d5cf 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -1,10 +1,10 @@
 
 /* pngwrite.c - general routines to write a png file
 
-   libpng 1.0 beta 2 - version 0.81
+	libpng 1.0 beta 2 - version 0.85
    For conditions of distribution and use, see copyright notice in png.h
    Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
-   August 24, 1995
+   December 19, 1995
    */
 
 /* get internal access to png.h */
@@ -16,12 +16,12 @@
    write it, and put it in the correct location here.  If you want
    the chunk written after the image data, put it in png_write_end().
    I strongly encurage you to supply a PNG_INFO_ flag, and check
-   info->valid before writing the chunk, as that will keep the code
+	info->valid before writing the chunk, as that will keep the code
    from breaking if you want to just write a plain png file.
    If you have long comments, I suggest writing them in png_write_end(),
    and compressing them. */
 void
-png_write_info(png_struct *png_ptr, png_info *info)
+png_write_info(png_structp png_ptr, png_infop info)
 {
    png_write_sig(png_ptr); /* write PNG signature */
    /* write IHDR information. */
@@ -57,30 +57,25 @@
    if (info->valid & PNG_INFO_bKGD)
       png_write_bKGD(png_ptr, &(info->background), info->color_type);
 #endif
-
 #if defined(PNG_WRITE_hIST_SUPPORTED)
    if (info->valid & PNG_INFO_hIST)
       png_write_hIST(png_ptr, info->hist, info->num_palette);
 #endif
-
 #if defined(PNG_WRITE_pHYs_SUPPORTED)
    if (info->valid & PNG_INFO_pHYs)
       png_write_pHYs(png_ptr, info->x_pixels_per_unit,
          info->y_pixels_per_unit, info->phys_unit_type);
 #endif
-
 #if defined(PNG_WRITE_oFFs_SUPPORTED)
    if (info->valid & PNG_INFO_oFFs)
       png_write_oFFs(png_ptr, info->x_offset, info->y_offset,
          info->offset_unit_type);
 #endif
-
 #if defined(PNG_WRITE_tIME_SUPPORTED)
    if (info->valid & PNG_INFO_tIME)
       png_write_tIME(png_ptr, &(info->mod_time));
    /* Check to see if we need to write text chunks */
 #endif
-
 #if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
    if (info->num_text)
    {
@@ -89,17 +84,11 @@
       /* loop through the text chunks */
       for (i = 0; i < info->num_text; i++)
       {
-         if (strlen(info->text[i].key) > 80)
-         {
-            (*(png_ptr->warning_fn))(png_ptr,"tEXt keyword more than 80 chars");
-            continue;
-         }
-
          /* if chunk is compressed */
          if (info->text[i].compression >= 0)
          {
 #if defined(PNG_WRITE_zTXt_SUPPORTED)
-            /* write compressed chunk */
+				/* write compressed chunk */
             png_write_zTXt(png_ptr, info->text[i].key,
                info->text[i].text, info->text[i].text_length,
                info->text[i].compression);
@@ -110,13 +99,12 @@
 #if defined(PNG_WRITE_tEXt_SUPPORTED)
             /* write uncompressed chunk */
             png_write_tEXt(png_ptr, info->text[i].key,
-               info->text[i].text, info->text[i].text_length);
+					info->text[i].text, info->text[i].text_length);
 #endif
          }
       }
    }
-#endif /* PNG_WRITE_tEXt_SUPPORTED || PNG_WRITE_zTXt_SUPPORTED */
-   png_ptr->mode = PNG_HAVE_IHDR;
+#endif
 }
 
 /* writes the end of the png file.  If you don't want to write comments or
@@ -124,11 +112,8 @@
    in png_write_info(), do not write them again here.  If you have long
    comments, I suggest writing them here, and compressing them. */
 void
-png_write_end(png_struct *png_ptr, png_info *info)
+png_write_end(png_structp png_ptr, png_infop info)
 {
-   if (info && png_ptr->mode == PNG_AFTER_IEND)
-     return;
-
    /* see if user wants us to write information chunks */
    if (info)
    {
@@ -137,7 +122,6 @@
       if (info->valid & PNG_INFO_tIME)
          png_write_tIME(png_ptr, &(info->mod_time));
 #endif
-
 #if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
       /* check to see if we need to write comment chunks */
       if (info->num_text)
@@ -146,7 +130,7 @@
 
          /* loop through comment chunks */
          for (i = 0; i < info->num_text; i++)
-         {
+			{
             /* check to see if comment is to be compressed */
             if (info->text[i].compression >= 0)
             {
@@ -164,51 +148,59 @@
                png_write_tEXt(png_ptr, info->text[i].key,
                   info->text[i].text, info->text[i].text_length);
 #endif
-            }
+				}
          }
       }
-#endif /* PNG_WRITE_tEXt_SUPPORTED || PNG_WRITE_zTXt_SUPPORTED */
+#endif
    }
    /* write end of png file */
    png_write_IEND(png_ptr);
-
-   png_ptr->mode = PNG_AFTER_IEND;
 }
 
 #if defined(PNG_WRITE_tIME_SUPPORTED)
 void
-png_convert_from_struct_tm(png_time *ptime, struct tm *ttime)
+png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
 {
-   ptime->year = 1900 + ttime->tm_year;
-   ptime->month = ttime->tm_mon + 1;
-   ptime->day = ttime->tm_mday;
-   ptime->hour = ttime->tm_hour;
-   ptime->minute = ttime->tm_min;
-   ptime->second = ttime->tm_sec;
+	ptime->year = 1900 + ttime->tm_year;
+	ptime->month = ttime->tm_mon + 1;
+	ptime->day = ttime->tm_mday;
+	ptime->hour = ttime->tm_hour;
+	ptime->minute = ttime->tm_min;
+	ptime->second = ttime->tm_sec;
 }
 
 void
-png_convert_from_time_t(png_time *ptime, time_t ttime)
+png_convert_from_time_t(png_timep ptime, time_t ttime)
 {
    struct tm *tbuf;
 
    tbuf = gmtime(&ttime);
    png_convert_from_struct_tm(ptime, tbuf);
 }
-#endif /* PNG_WRITE_tIME_SUPPORTED */
+#endif
 
 /* initialize png structure, and allocate any memory needed */
 void
-png_write_init(png_struct *png_ptr)
+png_write_init(png_structp png_ptr)
 {
    jmp_buf tmp_jmp; /* to save current jump buffer */
+	png_msg_ptr error_fn;
+	png_msg_ptr warning_fn;
+	png_voidp msg_ptr;
 
-   /* save jump buffer */
-   png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
-   /* reset all variables to 0 */
-   png_memset(png_ptr, 0, sizeof (png_struct));
-   /* restore jump buffer */
+	/* save jump buffer and error functions */
+	png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+	error_fn = png_ptr->error_fn;
+	warning_fn = png_ptr->warning_fn;
+	msg_ptr = png_ptr->msg_ptr;
+
+	/* reset all variables to 0 */
+	png_memset(png_ptr, 0, sizeof (png_struct));
+	/* restore jump buffer and error functions */
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+	png_ptr->error_fn = error_fn;
+	png_ptr->warning_fn = warning_fn;
+	png_ptr->msg_ptr = msg_ptr;
 
    /* initialize zbuf - compression buffer */
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
@@ -218,13 +210,13 @@
 /* write a few rows of image data.  If the image is interlaced,
    either you will have to write the 7 sub images, or, if you
    have called png_set_interlace_handling(), you will have to
-   "write" the image seven times */
+	"write" the image seven times */
 void
-png_write_rows(png_struct *png_ptr, png_bytef **row,
+png_write_rows(png_structp png_ptr, png_bytepp row,
    png_uint_32 num_rows)
 {
    png_uint_32 i; /* row counter */
-   png_bytef **rp; /* row pointer */
+   png_bytepp rp; /* row pointer */
 
    /* loop through the rows */
    for (i = 0, rp = row; i < num_rows; i++, rp++)
@@ -236,11 +228,11 @@
 /* write the image.  You only need to call this function once, even
    if you are writing an interlaced image. */
 void
-png_write_image(png_struct *png_ptr, png_bytef **image)
+png_write_image(png_structp png_ptr, png_bytepp image)
 {
    png_uint_32 i; /* row index */
    int pass, num_pass; /* pass variables */
-   png_bytef **rp; /* points to current row */
+   png_bytepp rp; /* points to current row */
 
    /* intialize interlace handling.  If image is not interlaced,
       this will set pass to 1 */
@@ -258,23 +250,21 @@
 
 /* write a row of image data */
 void
-png_write_row(png_struct *png_ptr, png_bytef *row)
+png_write_row(png_structp png_ptr, png_bytep row)
 {
    /* initialize transformations and other stuff if first time */
-   if (png_ptr->mode < PNG_HAVE_IDAT)
+   if (png_ptr->row_number == 0 && png_ptr->pass == 0)
    {
       png_write_start_row(png_ptr);
    }
 
-   png_ptr->mode = PNG_HAVE_IDAT;
-
 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
    /* if interlaced and not interested in row, return */
    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
    {
       switch (png_ptr->pass)
       {
-         case 0:
+			case 0:
             if (png_ptr->row_number & 7)
             {
                png_write_finish_row(png_ptr);
@@ -292,7 +282,7 @@
             if ((png_ptr->row_number & 7) != 4)
             {
                png_write_finish_row(png_ptr);
-               return;
+					return;
             }
             break;
          case 3:
@@ -310,7 +300,7 @@
             }
             break;
          case 5:
-            if ((png_ptr->row_number & 1) || png_ptr->width < 2)
+				if ((png_ptr->row_number & 1) || png_ptr->width < 2)
             {
                png_write_finish_row(png_ptr);
                return;
@@ -325,10 +315,10 @@
             break;
       }
    }
-#endif /* PNG_WRITE_INTERLACE_SUPPORTED */
+#endif
 
    /* set up row info for transformations */
-   png_ptr->row_info.color_type = png_ptr->color_type;
+	png_ptr->row_info.color_type = png_ptr->color_type;
    png_ptr->row_info.width = png_ptr->usr_width;
    png_ptr->row_info.channels = png_ptr->usr_channels;
    png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
@@ -346,7 +336,7 @@
       (png_ptr->transformations & PNG_INTERLACE))
    {
       png_do_write_interlace(&(png_ptr->row_info),
-         png_ptr->row_buf + 1, png_ptr->pass);
+			png_ptr->row_buf + 1, png_ptr->pass);
       /* this should always get caught above, but still ... */
       if (!(png_ptr->row_info.width))
       {
@@ -354,7 +344,7 @@
          return;
       }
    }
-#endif /* PNG_WRITE_INTERLACE_SUPPORTED */
+#endif
 
    /* handle other transformations */
    if (png_ptr->transformations)
@@ -364,7 +354,7 @@
    if (png_ptr->do_filter)
    {
       /* save row to previous row */
-      png_memcpy(png_ptr->save_row, png_ptr->row_buf,
+		png_memcpy(png_ptr->save_row, png_ptr->row_buf,
          (png_size_t)png_ptr->row_info.rowbytes + 1);
 
       /* filter row */
@@ -373,7 +363,7 @@
 
       /* trade saved pointer and prev pointer so next row references are correctly */
       { /* scope limiter */
-         png_bytef *tptr;
+			png_bytep tptr;
 
          tptr = png_ptr->prev_row;
          png_ptr->prev_row = png_ptr->save_row;
@@ -382,12 +372,11 @@
    }
    else
       /* set filter row to "none" */
-      png_ptr->row_buf[0] = 0;
+		png_ptr->row_buf[0] = 0;
 
    /* set up the zlib input buffer */
    png_ptr->zstream->next_in = png_ptr->row_buf;
    png_ptr->zstream->avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
-
    /* repeat until we have compressed all the data */
    do
    {
@@ -399,9 +388,9 @@
       if (ret != Z_OK)
       {
          if (png_ptr->zstream->msg)
-            (*(png_ptr->error_fn))(png_ptr, png_ptr->zstream->msg);
-         else
-            (*(png_ptr->error_fn))(png_ptr, "zlib error");
+            png_error(png_ptr, png_ptr->zstream->msg);
+			else
+				png_error(png_ptr, "zlib error");
       }
 
       /* see if it is time to write another IDAT */
@@ -415,17 +404,17 @@
    /* repeat until all data has been compressed */
    } while (png_ptr->zstream->avail_in);
 
-   /* finish row - updates counters and flushes zlib if last row */
-   png_write_finish_row(png_ptr);
+	/* finish row - updates counters and flushes zlib if last row */
+	png_write_finish_row(png_ptr);
 
 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
-   png_ptr->flush_rows++;
+	png_ptr->flush_rows++;
 
-   if (png_ptr->flush_dist > 0 &&
-       png_ptr->flush_rows >= png_ptr->flush_dist)
-   {
-      png_write_flush(png_ptr);
-   }
+	if (png_ptr->flush_dist > 0 &&
+		 png_ptr->flush_rows >= png_ptr->flush_dist)
+	{
+		png_write_flush(png_ptr);
+	}
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 }
 
@@ -434,68 +423,70 @@
 void
 png_set_flush(png_struct *png_ptr, int nrows)
 {
-   png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
+	png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
 }
 
 /* flush the current output buffers now */
 void
 png_write_flush(png_struct *png_ptr)
 {
-   char wrote_IDAT;
+	int wrote_IDAT;
 
-   if (png_ptr->mode != PNG_HAVE_IDAT)
-     return;
+	if (png_ptr->mode != PNG_HAVE_IDAT)
+	  return;
 
-   do
-   {
-      int ret;
+	do
+	{
+		int ret;
 
-      /* compress the data */
-      ret = deflate(png_ptr->zstream, Z_SYNC_FLUSH);
-      wrote_IDAT = 0;
+		/* compress the data */
+		ret = deflate(png_ptr->zstream, Z_SYNC_FLUSH);
+		wrote_IDAT = 0;
 
-      /* check for compression errors */
-      if (ret != Z_OK)
-      {
-         if (png_ptr->zstream->msg)
-            (*(png_ptr->error_fn))(png_ptr, png_ptr->zstream->msg);
-         else
-            (*(png_ptr->error_fn))(png_ptr, "zlib error");
-      }
+		/* check for compression errors */
+		if (ret != Z_OK)
+		{
+			if (png_ptr->zstream->msg)
+				png_error(png_ptr, png_ptr->zstream->msg);
+			else
+				png_error(png_ptr, "zlib error");
+		}
 
-      if (!png_ptr->zstream->avail_out)
-      {
-         /* write the IDAT and reset the zlib output buffer */
-         png_write_IDAT(png_ptr, png_ptr->zbuf,
-                        png_ptr->zbuf_size);
-         png_ptr->zstream->next_out = png_ptr->zbuf;
-         png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size;
-         wrote_IDAT = 1;
-      }
-   } while(wrote_IDAT == 1);
+		if (!png_ptr->zstream->avail_out)
+		{
+			/* write the IDAT and reset the zlib output buffer */
+			png_write_IDAT(png_ptr, png_ptr->zbuf,
+								png_ptr->zbuf_size);
+			png_ptr->zstream->next_out = png_ptr->zbuf;
+			png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size;
+			wrote_IDAT = 1;
+		}
+	} while(wrote_IDAT == 1);
 
-   /* If there is any data left to be output, write it into a new IDAT */
-   if (png_ptr->zbuf_size != png_ptr->zstream->avail_out)
-   {
-      /* write the IDAT and reset the zlib output buffer */
-      png_write_IDAT(png_ptr, png_ptr->zbuf,
-                     png_ptr->zbuf_size - png_ptr->zstream->avail_out);
-      png_ptr->zstream->next_out = png_ptr->zbuf;
-      png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size;
-   }
-   png_ptr->flush_rows = 0;
-   (*(png_ptr->output_flush_fn))(png_ptr);
+	/* If there is any data left to be output, write it into a new IDAT */
+	if (png_ptr->zbuf_size != png_ptr->zstream->avail_out)
+	{
+		/* write the IDAT and reset the zlib output buffer */
+		png_write_IDAT(png_ptr, png_ptr->zbuf,
+							png_ptr->zbuf_size - png_ptr->zstream->avail_out);
+		png_ptr->zstream->next_out = png_ptr->zbuf;
+		png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size;
+	}
+	png_ptr->flush_rows = 0;
+	png_flush(png_ptr);
 }
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 
+
 /* free any memory used in png struct */
 void
-png_write_destroy(png_struct *png_ptr)
+png_write_destroy(png_structp png_ptr)
 {
-   jmp_buf tmp_jmp; /* save jump buffer */
+	jmp_buf tmp_jmp; /* save jump buffer */
 
    /* free any memory zlib uses */
-   deflateEnd(png_ptr->zstream);
+	deflateEnd(png_ptr->zstream);
+   png_free(png_ptr, png_ptr->zstream);
    /* free our memory.  png_free checks NULL for us. */
    png_large_free(png_ptr, png_ptr->zbuf);
    png_large_free(png_ptr, png_ptr->row_buf);
@@ -506,44 +497,43 @@
    png_memset(png_ptr, 0, sizeof (png_struct));
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
 }
-
 void
-png_set_filtering(png_struct *png_ptr, int filter)
+png_set_filtering(png_structp png_ptr, int filter)
 {
    png_ptr->do_custom_filter = 1;
    png_ptr->do_filter = filter;
 }
 
 void
-png_set_compression_level(png_struct *png_ptr, int level)
+png_set_compression_level(png_structp png_ptr, int level)
 {
    png_ptr->zlib_custom_level = 1;
    png_ptr->zlib_level = level;
 }
 
 void
-png_set_compression_mem_level(png_struct *png_ptr, int mem_level)
+png_set_compression_mem_level(png_structp png_ptr, int mem_level)
 {
    png_ptr->zlib_custom_mem_level = 1;
-   png_ptr->zlib_mem_level = mem_level;
+	png_ptr->zlib_mem_level = mem_level;
 }
 
 void
-png_set_compression_strategy(png_struct *png_ptr, int strategy)
+png_set_compression_strategy(png_structp png_ptr, int strategy)
 {
    png_ptr->zlib_custom_strategy = 1;
    png_ptr->zlib_strategy = strategy;
 }
 
 void
-png_set_compression_window_bits(png_struct *png_ptr, int window_bits)
+png_set_compression_window_bits(png_structp png_ptr, int window_bits)
 {
    png_ptr->zlib_custom_window_bits = 1;
    png_ptr->zlib_window_bits = window_bits;
 }
 
 void
-png_set_compression_method(png_struct *png_ptr, int method)
+png_set_compression_method(png_structp png_ptr, int method)
 {
    png_ptr->zlib_custom_method = 1;
    png_ptr->zlib_method = method;