From 2130a3cd203a725e15dc8123909fa13018a3b232 Mon Sep 17 00:00:00 2001
From: Glenn Randers-Pehrson <glennrp at users.sourceforge.net>
Date: Sun, 15 Feb 2015 13:18:50 -0600
Subject: [PATCH] [libpng17] Combined several redundant lines of code in
 pngwutil.c

---
 pngwutil.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/pngwutil.c b/pngwutil.c
index a78c1d342..a6ab45b0d 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -2360,6 +2360,8 @@ png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp,
    png_size_t sum = 0;
    int v;
 
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
+
    for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp;
         i++, rp++, dp++)
    {
@@ -2397,6 +2399,8 @@ png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes,
    png_size_t sum = 0;
    int v;
 
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
+
    for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
        pp = png_ptr->prev_row + 1; i < row_bytes;
        i++, rp++, pp++, dp++)
@@ -2428,6 +2432,8 @@ png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp,
    png_size_t sum = 0;
    int v;
 
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
+
    for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
         pp = png_ptr->prev_row + 1; i < bpp; i++)
    {
@@ -2467,6 +2473,8 @@ png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp,
    png_size_t sum = 0;
    int v;
 
+   png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
+
    for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1,
        pp = png_ptr->prev_row + 1; i < bpp; i++)
    {
@@ -2586,6 +2594,7 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
     * that has been chosen, as it doesn't actually do anything to the data.
     */
    best_row = png_ptr->row_buf;
+   png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
 
    if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE)
    {
@@ -2594,7 +2603,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       png_size_t i;
       int v;
 
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_NONE;
       for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
       {
          v = *rp;
@@ -2647,7 +2655,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
    if (filter_to_do == PNG_FILTER_SUB)
    /* It's the only filter so no testing is needed */
    {
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
       (void) png_setup_sub_row(png_ptr, bpp, row_bytes, mins); 
       best_row = png_ptr->try_row;
    }
@@ -2657,8 +2664,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       png_size_t sum;
       png_size_t lmins = mins;
 
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB;
-
 #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
@@ -2748,7 +2753,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
    /* Up filter */
    if (filter_to_do == PNG_FILTER_UP)
    {
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
       (void) png_setup_up_row(png_ptr, row_bytes, mins);
       best_row = png_ptr->try_row;
    }
@@ -2758,8 +2762,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       png_size_t sum;
       png_size_t lmins = mins;
 
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_UP;
-
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
       {
@@ -2845,7 +2847,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
    /* Avg filter */
    if (filter_to_do == PNG_FILTER_AVG)
    {
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
       (void) png_setup_avg_row(png_ptr, bpp, row_bytes, mins);
       best_row = png_ptr->try_row;
    }
@@ -2855,7 +2856,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       png_size_t sum;
       png_size_t lmins = mins;
 
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG;
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
       {
@@ -2941,7 +2941,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
    /* Paeth filter */
    if ((filter_to_do == PNG_FILTER_PAETH) != 0)
    {
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
       (void) png_setup_paeth_row(png_ptr, bpp, row_bytes, mins);
       best_row = png_ptr->try_row;
    }
@@ -2951,7 +2950,6 @@ png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
       png_size_t sum;
       png_size_t lmins = mins;
 
-      png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH;
 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
       if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
       {