third_party/libpng: update to 1.2.54

third_party/libpng/pngwutil.c

 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.2.43 [February 25, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.54 [November 12, 2015]
+ * Copyright (c) 1998-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
  * and license in png.h
  */
 
 #define PNG_INTERNAL
 #define PNG_NO_PEDANTIC_WARNINGS
@@ skipping 231 matching lines @@
 
             old_max = comp->max_output_ptr;
             comp->max_output_ptr = comp->num_output_ptr + 4;
             if (comp->output_ptr != NULL)
             {
                png_charpp old_ptr;
 
                old_ptr = comp->output_ptr;
                comp->output_ptr = (png_charpp)png_malloc(png_ptr,
                   (png_uint_32)
-                  (comp->max_output_ptr * png_sizeof(png_charpp)));
+                  (comp->max_output_ptr * png_sizeof(png_charp)));
                png_memcpy(comp->output_ptr, old_ptr, old_max
                   * png_sizeof(png_charp));
                png_free(png_ptr, old_ptr);
             }
             else
                comp->output_ptr = (png_charpp)png_malloc(png_ptr,
                   (png_uint_32)
                   (comp->max_output_ptr * png_sizeof(png_charp)));
          }
 
@@ skipping 300 matching lines @@
 /* Write the palette.  We are careful not to trust png_color to be in the
  * correct order for PNG, so people can redefine it to any convenient
  * structure.
  */
 void /* PRIVATE */
 png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
 {
 #ifdef PNG_USE_LOCAL_ARRAYS
    PNG_PLTE;
 #endif
-   png_uint_32 i;
+   png_uint_32 max_palette_length, i;
    png_colorp pal_ptr;
    png_byte buf[3];
 
    png_debug(1, "in png_write_PLTE");
 
+   max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+      (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+
    if ((
 #ifdef PNG_MNG_FEATURES_SUPPORTED
         !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
 #endif
-        num_pal == 0) || num_pal > 256)
+       num_pal == 0) || num_pal > max_palette_length)
    {
      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
      {
         png_error(png_ptr, "Invalid number of colors in palette");
      }
      else
      {
         png_warning(png_ptr, "Invalid number of colors in palette");
         return;
      }
@@ skipping 1153 matching lines @@
 
    png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
 }
 #endif
 
 /* Initializes the row writing capability of libpng */
 void /* PRIVATE */
 png_write_start_row(png_structp png_ptr)
 {
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
+#ifndef PNG_USE_GLOBAL_ARRAYS
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
    int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
 
    /* Offset to next interlace block */
    int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
 
    /* Start of interlace block in the y direction */
    int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
 
    /* Offset to next interlace block in the y direction */
    int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
 #endif
+#endif
 
    png_size_t buf_size;
 
    png_debug(1, "in png_write_start_row");
 
    buf_size = (png_size_t)(PNG_ROWBYTES(
       png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1);
 
    /* Set up row buffer */
    png_ptr->row_buf = (png_bytep)png_malloc(png_ptr,
@@ skipping 64 matching lines @@
    }
    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
    png_ptr->zstream.next_out = png_ptr->zbuf;
 }
 
 /* Internal use only.  Called when finished processing a row of data. */
 void /* PRIVATE */
 png_write_finish_row(png_structp png_ptr)
 {
 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
+#ifndef PNG_USE_GLOBAL_ARRAYS
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
    int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
 
    /* Offset to next interlace block */
    int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
 
    /* Start of interlace block in the y direction */
    int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
 
    /* Offset to next interlace block in the y direction */
    int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
 #endif
+#endif
 
    int ret;
 
    png_debug(1, "in png_write_finish_row");
 
    /* Next row */
    png_ptr->row_number++;
 
    /* See if we are done */
    if (png_ptr->row_number < png_ptr->num_rows)
@@ skipping 85 matching lines @@
  * pointer and a destination pointer (sp and dp), and copy the
  * correct pixels for the pass.  As the row gets compacted,
  * sp will always be >= dp, so we should never overwrite anything.
  * See the default: case for the easiest code to understand.
  */
 void /* PRIVATE */
 png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
 {
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
+#ifndef PNG_USE_GLOBAL_ARRAYS
    /* Start of interlace block */
    int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
 
    /* Offset to next interlace block */
    int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+#endif
 
    png_debug(1, "in png_do_write_interlace");
 
    /* We don't have to do anything on the last pass (6) */
 #ifdef PNG_USELESS_TESTS_SUPPORTED
    if (row != NULL && row_info != NULL && pass < 6)
 #else
    if (pass < 6)
 #endif
    {
@@ skipping 149 matching lines @@
 #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
 void /* PRIVATE */
 png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
 {
    png_bytep best_row;
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    png_bytep prev_row, row_buf;
    png_uint_32 mins, bpp;
    png_byte filter_to_do = png_ptr->do_filter;
    png_uint_32 row_bytes = row_info->rowbytes;
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   int num_p_filters = (int)png_ptr->num_prev_filters;
-#endif 
 
    png_debug(1, "in png_write_find_filter");
 
-#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-  if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
-  {
-      /* These will never be selected so we need not test them. */
-      filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
-  }
-#endif 
-
    /* Find out how many bytes offset each pixel is */
    bpp = (row_info->pixel_depth + 7) >> 3;
 
    prev_row = png_ptr->prev_row;
 #endif
    best_row = png_ptr->row_buf;
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    row_buf = best_row;
    mins = PNG_MAXSUM;
 
@@ skipping 29 matching lines @@
       png_uint_32 sum = 0;
       png_uint_32 i;
       int v;
 
       for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
       {
          v = *rp;
          sum += (v < 128) ? v : 256 - v;
       }
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         png_uint_32 sumhi, sumlo;
-         int j;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
-
-         /* Reduce the sum if we match any of the previous rows */
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         /* Factor in the cost of this filter (this is here for completeness,
-          * but it makes no sense to have a "cost" for the NONE filter, as
-          * it has the minimum possible computational cost - none).
-          */
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
-            PNG_COST_SHIFT;
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
-            PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
       mins = sum;
    }
 
    /* Sub filter */
    if (filter_to_do == PNG_FILTER_SUB)
    /* It's the only filter so no testing is needed */
    {
       png_bytep rp, lp, dp;
       png_uint_32 i;
       for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
            i++, rp++, dp++)
       {
          *dp = *rp;
       }
       for (lp = row_buf + 1; i < row_bytes;
          i++, rp++, lp++, dp++)
       {
          *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
       }
       best_row = png_ptr->sub_row;
    }
 
    else if (filter_to_do & PNG_FILTER_SUB)
    {
       png_bytep rp, dp, lp;
       png_uint_32 sum = 0, lmins = mins;
       png_uint_32 i;
       int v;
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      /* We temporarily increase the "minimum sum" by the factor we
-       * would reduce the sum of this filter, so that we can do the
-       * early exit comparison without scaling the sum each time.
-       */
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-            PNG_COST_SHIFT;
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-            PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
       for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
            i++, rp++, dp++)
       {
          v = *dp = *rp;
 
          sum += (v < 128) ? v : 256 - v;
       }
       for (lp = row_buf + 1; i < row_bytes;
          i++, rp++, lp++, dp++)
       {
          v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;
 
          if (sum > lmins)  /* We are already worse, don't continue. */
             break;
       }
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
-            {
-               sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-            PNG_COST_SHIFT;
-         sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
-            PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
       if (sum < mins)
       {
          mins = sum;
          best_row = png_ptr->sub_row;
       }
    }
 
    /* Up filter */
    if (filter_to_do == PNG_FILTER_UP)
    {
       png_bytep rp, dp, pp;
       png_uint_32 i;
 
       for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
            pp = prev_row + 1; i < row_bytes;
            i++, rp++, pp++, dp++)
       {
          *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
       }
       best_row = png_ptr->up_row;
    }
 
    else if (filter_to_do & PNG_FILTER_UP)
    {
       png_bytep rp, dp, pp;
       png_uint_32 sum = 0, lmins = mins;
       png_uint_32 i;
       int v;
 
-
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
-            PNG_COST_SHIFT;
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
-            PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
       for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
            pp = prev_row + 1; i < row_bytes; i++)
       {
          v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;
 
          if (sum > lmins)  /* We are already worse, don't continue. */
             break;
       }
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
-            PNG_COST_SHIFT;
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
-            PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
       if (sum < mins)
       {
          mins = sum;
          best_row = png_ptr->up_row;
       }
    }
 
    /* Avg filter */
    if (filter_to_do == PNG_FILTER_AVG)
    {
@@ skipping 12 matching lines @@
       best_row = png_ptr->avg_row;
    }
 
    else if (filter_to_do & PNG_FILTER_AVG)
    {
       png_bytep rp, dp, pp, lp;
       png_uint_32 sum = 0, lmins = mins;
       png_uint_32 i;
       int v;
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
-            PNG_COST_SHIFT;
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
-            PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
       for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
            pp = prev_row + 1; i < bpp; i++)
       {
          v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;
       }
       for (lp = row_buf + 1; i < row_bytes; i++)
       {
          v = *dp++ =
           (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;
 
          if (sum > lmins)  /* We are already worse, don't continue. */
             break;
       }
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
-            PNG_COST_SHIFT;
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
-            PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
       if (sum < mins)
       {
          mins = sum;
          best_row = png_ptr->avg_row;
       }
    }
 
    /* Paeth filter */
    if (filter_to_do == PNG_FILTER_PAETH)
    {
@@ skipping 33 matching lines @@
       best_row = png_ptr->paeth_row;
    }
 
    else if (filter_to_do & PNG_FILTER_PAETH)
    {
       png_bytep rp, dp, pp, cp, lp;
       png_uint_32 sum = 0, lmins = mins;
       png_uint_32 i;
       int v;
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 lmhi, lmlo;
-         lmlo = lmins & PNG_LOMASK;
-         lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
-            {
-               lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-            PNG_COST_SHIFT;
-         lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-            PNG_COST_SHIFT;
-
-         if (lmhi > PNG_HIMASK)
-            lmins = PNG_MAXSUM;
-         else
-            lmins = (lmhi << PNG_HISHIFT) + lmlo;
-      }
-#endif
-
       for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
            pp = prev_row + 1; i < bpp; i++)
       {
          v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;
       }
 
       for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
       {
@@ skipping 30 matching lines @@
 #endif /* PNG_SLOW_PAETH */
 
          v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;
 
          if (sum > lmins)  /* We are already worse, don't continue. */
             break;
       }
 
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-      if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
-      {
-         int j;
-         png_uint_32 sumhi, sumlo;
-         sumlo = sum & PNG_LOMASK;
-         sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
-
-         for (j = 0; j < num_p_filters; j++)
-         {
-            if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
-            {
-               sumlo = (sumlo * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-               sumhi = (sumhi * png_ptr->filter_weights[j]) >>
-                  PNG_WEIGHT_SHIFT;
-            }
-         }
-
-         sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-            PNG_COST_SHIFT;
-         sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
-            PNG_COST_SHIFT;
-
-         if (sumhi > PNG_HIMASK)
-            sum = PNG_MAXSUM;
-         else
-            sum = (sumhi << PNG_HISHIFT) + sumlo;
-      }
-#endif
-
       if (sum < mins)
       {
          best_row = png_ptr->paeth_row;
       }
    }
 #endif /* PNG_WRITE_FILTER_SUPPORTED */
    /* Do the actual writing of the filtered row data from the chosen filter. */
 
    png_write_filtered_row(png_ptr, best_row);
-
-#ifdef PNG_WRITE_FILTER_SUPPORTED
-#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
-   /* Save the type of filter we picked this time for future calculations */
-   if (png_ptr->num_prev_filters > 0)
-   {
-      int j;
-      for (j = 1; j < num_p_filters; j++)
-      {
-         png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
-      }
-      png_ptr->prev_filters[j] = best_row[0];
-   }
-#endif
-#endif /* PNG_WRITE_FILTER_SUPPORTED */
 }
 
 
 /* Do the actual writing of a previously filtered row. */
 void /* PRIVATE */
 png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
 {
    png_debug(1, "in png_write_filtered_row");
 
    png_debug1(2, "filter = %d", filtered_row[0]);
@@ skipping 45 matching lines @@
    png_ptr->flush_rows++;
 
    if (png_ptr->flush_dist > 0 &&
        png_ptr->flush_rows >= png_ptr->flush_dist)
    {
       png_write_flush(png_ptr);
    }
 #endif
 }
 #endif /* PNG_WRITE_SUPPORTED */