From c554ec47dca508a085c4206aea5cc5cadc1311fb Mon Sep 17 00:00:00 2001
From: George Hazan <george.hazan@gmail.com>
Date: Thu, 18 Dec 2014 11:45:07 +0000
Subject: libpng updated to 1.6.15

git-svn-id: http://svn.miranda-ng.org/main/trunk@11507 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
---
 plugins/AdvaImg/src/LibPNG/pngrtran.c | 415 +++++++++++++++++-----------------
 1 file changed, 209 insertions(+), 206 deletions(-)

(limited to 'plugins/AdvaImg/src/LibPNG/pngrtran.c')

diff --git a/plugins/AdvaImg/src/LibPNG/pngrtran.c b/plugins/AdvaImg/src/LibPNG/pngrtran.c
index ae5deaeacc..c4dba7f686 100644
--- a/plugins/AdvaImg/src/LibPNG/pngrtran.c
+++ b/plugins/AdvaImg/src/LibPNG/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.15 [November 20, 2014]
  * Copyright (c) 1998-2014 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.)
@@ -91,14 +91,15 @@ png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
 /* Is it OK to set a transformation now?  Only if png_start_read_image or
  * png_read_update_info have not been called.  It is not necessary for the IHDR
- * to have been read in all cases, the parameter allows for this check too.
+ * to have been read in all cases; the need_IHDR parameter allows for this
+ * check too.
  */
 static int
 png_rtran_ok(png_structrp png_ptr, int need_IHDR)
 {
    if (png_ptr != NULL)
    {
-      if (png_ptr->flags & PNG_FLAG_ROW_INIT)
+      if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
          png_app_error(png_ptr,
             "invalid after png_start_read_image or png_read_update_info");
 
@@ -127,7 +128,7 @@ png_set_background_fixed(png_structrp png_ptr,
 {
    png_debug(1, "in png_set_background_fixed");
 
-   if (!png_rtran_ok(png_ptr, 0) || background_color == NULL)
+   if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL)
       return;
 
    if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
@@ -143,7 +144,7 @@ png_set_background_fixed(png_structrp png_ptr,
    png_ptr->background = *background_color;
    png_ptr->background_gamma = background_gamma;
    png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
-   if (need_expand)
+   if (need_expand != 0)
       png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
    else
       png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
@@ -171,7 +172,7 @@ png_set_scale_16(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_scale_16");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= PNG_SCALE_16_TO_8;
@@ -185,7 +186,7 @@ png_set_strip_16(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_strip_16");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= PNG_16_TO_8;
@@ -198,7 +199,7 @@ png_set_strip_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_strip_alpha");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= PNG_STRIP_ALPHA;
@@ -226,7 +227,7 @@ translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
 #     else
          PNG_UNUSED(png_ptr)
 #     endif
-      if (is_screen)
+      if (is_screen != 0)
          output_gamma = PNG_GAMMA_sRGB;
       else
          output_gamma = PNG_GAMMA_sRGB_INVERSE;
@@ -235,7 +236,7 @@ translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
    else if (output_gamma == PNG_GAMMA_MAC_18 ||
       output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
    {
-      if (is_screen)
+      if (is_screen != 0)
          output_gamma = PNG_GAMMA_MAC_OLD;
       else
          output_gamma = PNG_GAMMA_MAC_INVERSE;
@@ -279,7 +280,7 @@ png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
 
    png_debug(1, "in png_set_alpha_mode");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
@@ -363,7 +364,7 @@ png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
    /* Finally, if pre-multiplying, set the background fields to achieve the
     * desired result.
     */
-   if (compose)
+   if (compose != 0)
    {
       /* And obtain alpha pre-multiplication by composing on black: */
       memset(&png_ptr->background, 0, (sizeof png_ptr->background));
@@ -371,7 +372,7 @@ png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
       png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
       png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
 
-      if (png_ptr->transformations & PNG_COMPOSE)
+      if ((png_ptr->transformations & PNG_COMPOSE) != 0)
          png_error(png_ptr,
             "conflicting calls to set alpha mode and background");
 
@@ -415,12 +416,12 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
 {
    png_debug(1, "in png_set_quantize");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= PNG_QUANTIZE;
 
-   if (!full_quantize)
+   if (full_quantize == 0)
    {
       int i;
 
@@ -475,12 +476,12 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
                }
             }
 
-            if (done)
+            if (done != 0)
                break;
          }
 
          /* Swap the palette around, and set up a table, if necessary */
-         if (full_quantize)
+         if (full_quantize != 0)
          {
             int j = num_palette;
 
@@ -663,7 +664,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
                         num_new_palette--;
                         palette[png_ptr->index_to_palette[j]]
                             = palette[num_new_palette];
-                        if (!full_quantize)
+                        if (full_quantize == 0)
                         {
                            int k;
 
@@ -731,7 +732,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
    }
    png_ptr->num_palette = (png_uint_16)num_palette;
 
-   if (full_quantize)
+   if (full_quantize != 0)
    {
       int i;
       png_bytep distance;
@@ -793,7 +794,7 @@ png_set_quantize(png_structrp png_ptr, png_colorp palette,
       png_free(png_ptr, distance);
    }
 }
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#endif /* READ_QUANTIZE */
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
 void PNGFAPI
@@ -802,7 +803,7 @@ png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
 {
    png_debug(1, "in png_set_gamma_fixed");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    /* New in libpng-1.5.4 - reserve particular negative values as flags. */
@@ -842,7 +843,7 @@ png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
    png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
       convert_gamma_value(png_ptr, file_gamma));
 }
-#  endif /* FLOATING_POINT_SUPPORTED */
+#  endif /* FLOATING_POINT */
 #endif /* READ_GAMMA */
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
@@ -855,7 +856,7 @@ png_set_expand(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_expand");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
@@ -885,7 +886,7 @@ png_set_palette_to_rgb(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_palette_to_rgb");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
@@ -897,7 +898,7 @@ png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= PNG_EXPAND;
@@ -909,12 +910,12 @@ png_set_tRNS_to_alpha(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_tRNS_to_alpha");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
 }
-#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
+#endif /* READ_EXPAND */
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
 /* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
@@ -925,7 +926,7 @@ png_set_expand_16(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_expand_16");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
@@ -938,7 +939,7 @@ png_set_gray_to_rgb(png_structrp png_ptr)
 {
    png_debug(1, "in png_set_gray_to_rgb");
 
-   if (!png_rtran_ok(png_ptr, 0))
+   if (png_rtran_ok(png_ptr, 0) == 0)
       return;
 
    /* Because rgb must be 8 bits or more: */
@@ -956,10 +957,10 @@ png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
 
    /* Need the IHDR here because of the check on color_type below. */
    /* TODO: fix this */
-   if (!png_rtran_ok(png_ptr, 1))
+   if (png_rtran_ok(png_ptr, 1) == 0)
       return;
 
-   switch(error_action)
+   switch (error_action)
    {
       case PNG_ERROR_ACTION_NONE:
          png_ptr->transformations |= PNG_RGB_TO_GRAY;
@@ -998,7 +999,7 @@ png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
          png_uint_16 red_int, green_int;
 
          /* NOTE: this calculation does not round, but this behavior is retained
-          * for consistency, the inaccuracy is very small.  The code here always
+          * for consistency; the inaccuracy is very small.  The code here always
           * overwrites the coefficients, regardless of whether they have been
           * defaulted or set already.
           */
@@ -1091,7 +1092,7 @@ png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
  * the palette.
  */
 
-/*For the moment 'png_init_palette_transformations' and
+/* For the moment 'png_init_palette_transformations' and
  * 'png_init_rgb_transformations' only do some flag canceling optimizations.
  * The intent is that these two routines should have palette or rgb operations
  * extracted from 'png_init_read_transformations'.
@@ -1131,7 +1132,7 @@ png_init_palette_transformations(png_structrp png_ptr)
    }
 
    /* If no alpha we can optimize. */
-   if (!input_has_alpha)
+   if (input_has_alpha == 0)
    {
       /* Any alpha means background and associative alpha processing is
        * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
@@ -1140,7 +1141,7 @@ png_init_palette_transformations(png_structrp png_ptr)
       png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
       png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
 
-      if (!input_has_transparency)
+      if (input_has_transparency == 0)
          png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
    }
 
@@ -1153,8 +1154,8 @@ png_init_palette_transformations(png_structrp png_ptr)
    /* The following code cannot be entered in the alpha pre-multiplication case
     * because PNG_BACKGROUND_EXPAND is cancelled below.
     */
-   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
-       (png_ptr->transformations & PNG_EXPAND))
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+       (png_ptr->transformations & PNG_EXPAND) != 0)
    {
       {
          png_ptr->background.red   =
@@ -1165,9 +1166,9 @@ png_init_palette_transformations(png_structrp png_ptr)
              png_ptr->palette[png_ptr->background.index].blue;
 
 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
-        if (png_ptr->transformations & PNG_INVERT_ALPHA)
+        if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
         {
-           if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+           if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
            {
               /* Invert the alpha channel (in tRNS) unless the pixels are
                * going to be expanded, in which case leave it for later
@@ -1179,10 +1180,10 @@ png_init_palette_transformations(png_structrp png_ptr)
                     png_ptr->trans_alpha[i]);
            }
         }
-#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */
+#endif /* READ_INVERT_ALPHA */
       }
    } /* background expand and (therefore) no alpha association. */
-#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
+#endif /* READ_EXPAND && READ_BACKGROUND */
 }
 
 static void /* PRIVATE */
@@ -1196,7 +1197,7 @@ png_init_rgb_transformations(png_structrp png_ptr)
    int input_has_transparency = png_ptr->num_trans > 0;
 
    /* If no alpha we can optimize. */
-   if (!input_has_alpha)
+   if (input_has_alpha == 0)
    {
       /* Any alpha means background and associative alpha processing is
        * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
@@ -1207,7 +1208,7 @@ png_init_rgb_transformations(png_structrp png_ptr)
          png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
 #     endif
 
-      if (!input_has_transparency)
+      if (input_has_transparency == 0)
          png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
    }
 
@@ -1220,9 +1221,9 @@ png_init_rgb_transformations(png_structrp png_ptr)
    /* The following code cannot be entered in the alpha pre-multiplication case
     * because PNG_BACKGROUND_EXPAND is cancelled below.
     */
-   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
-       (png_ptr->transformations & PNG_EXPAND) &&
-       !(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
+       (png_ptr->transformations & PNG_EXPAND) != 0 &&
+       (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
        /* i.e., GRAY or GRAY_ALPHA */
    {
       {
@@ -1260,14 +1261,14 @@ png_init_rgb_transformations(png_structrp png_ptr)
          png_ptr->background.red = png_ptr->background.green =
             png_ptr->background.blue = (png_uint_16)gray;
 
-         if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+         if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
          {
             png_ptr->trans_color.red = png_ptr->trans_color.green =
                png_ptr->trans_color.blue = (png_uint_16)trans_gray;
          }
       }
    } /* background expand and (therefore) no alpha association. */
-#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
+#endif /* READ_EXPAND && READ_BACKGROUND */
 }
 
 void /* PRIVATE */
@@ -1336,7 +1337,7 @@ png_init_read_transformations(png_structrp png_ptr)
        * the code immediately below if the transform can be handled outside the
        * row loop.
        */
-      if (gamma_correction)
+      if (gamma_correction != 0)
          png_ptr->transformations |= PNG_GAMMA;
 
       else
@@ -1345,7 +1346,7 @@ png_init_read_transformations(png_structrp png_ptr)
 #endif
 
    /* Certain transformations have the effect of preventing other
-    * transformations that happen afterward in png_do_read_transformations,
+    * transformations that happen afterward in png_do_read_transformations;
     * resolve the interdependencies here.  From the code of
     * png_do_read_transformations the order is:
     *
@@ -1374,8 +1375,8 @@ png_init_read_transformations(png_structrp png_ptr)
     * 23) PNG_USER_TRANSFORM [must be last]
     */
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
-   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
-      !(png_ptr->transformations & PNG_COMPOSE))
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) == 0)
    {
       /* Stripping the alpha channel happens immediately after the 'expand'
        * transformations, before all other transformation, so it cancels out
@@ -1401,7 +1402,7 @@ png_init_read_transformations(png_structrp png_ptr)
    /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
     * settings will have no effect.
     */
-   if (!png_gamma_significant(png_ptr->screen_gamma))
+   if (png_gamma_significant(png_ptr->screen_gamma) == 0)
    {
       png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
       png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
@@ -1412,7 +1413,7 @@ png_init_read_transformations(png_structrp png_ptr)
    /* Make sure the coefficients for the rgb to gray conversion are set
     * appropriately.
     */
-   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
       png_colorspace_set_rgb_coefficients(png_ptr);
 #endif
 
@@ -1433,23 +1434,23 @@ png_init_read_transformations(png_structrp png_ptr)
     * png_set_background, along with the bit depth, then the code has a record
     * of exactly what color space the background is currently in.
     */
-   if (png_ptr->transformations & PNG_BACKGROUND_EXPAND)
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0)
    {
       /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
        * the file was grayscale the background value is gray.
        */
-      if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR))
+      if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
          png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
    }
 
-   else if (png_ptr->transformations & PNG_COMPOSE)
+   else if ((png_ptr->transformations & PNG_COMPOSE) != 0)
    {
       /* PNG_COMPOSE: png_set_background was called with need_expand false,
        * so the color is in the color space of the output or png_set_alpha_mode
        * was called and the color is black.  Ignore RGB_TO_GRAY because that
        * happens before GRAY_TO_RGB.
        */
-      if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+      if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
       {
          if (png_ptr->background.red == png_ptr->background.green &&
              png_ptr->background.red == png_ptr->background.blue)
@@ -1459,8 +1460,8 @@ png_init_read_transformations(png_structrp png_ptr)
          }
       }
    }
-#endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */
-#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */
+#endif /* READ_EXPAND && READ_BACKGROUND */
+#endif /* READ_GRAY_TO_RGB */
 
    /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
     * can be performed directly on the palette, and some (such as rgb to gray)
@@ -1481,10 +1482,10 @@ png_init_read_transformations(png_structrp png_ptr)
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
    defined(PNG_READ_EXPAND_16_SUPPORTED)
-   if ((png_ptr->transformations & PNG_EXPAND_16) &&
-      (png_ptr->transformations & PNG_COMPOSE) &&
-      !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
-      png_ptr->bit_depth != 16)
+   if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+       png_ptr->bit_depth != 16)
    {
       /* TODO: fix this.  Because the expand_16 operation is after the compose
        * handling the background color must be 8, not 16, bits deep, but the
@@ -1503,15 +1504,15 @@ png_init_read_transformations(png_structrp png_ptr)
       CHOP(png_ptr->background.gray);
 #     undef CHOP
    }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */
+#endif /* READ_BACKGROUND && READ_EXPAND_16 */
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
    (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
    defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
-   if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) &&
-      (png_ptr->transformations & PNG_COMPOSE) &&
-      !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
-      png_ptr->bit_depth == 16)
+   if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
+       png_ptr->bit_depth == 16)
    {
       /* On the other hand, if a 16-bit file is to be reduced to 8-bits per
        * component this will also happen after PNG_COMPOSE and so the background
@@ -1554,25 +1555,24 @@ png_init_read_transformations(png_structrp png_ptr)
     * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
     * tables.
     */
-   if ((png_ptr->transformations & PNG_GAMMA)
-      || ((png_ptr->transformations & PNG_RGB_TO_GRAY)
-         && (png_gamma_significant(png_ptr->colorspace.gamma) ||
-            png_gamma_significant(png_ptr->screen_gamma)))
-      || ((png_ptr->transformations & PNG_COMPOSE)
-         && (png_gamma_significant(png_ptr->colorspace.gamma)
-            || png_gamma_significant(png_ptr->screen_gamma)
+   if ((png_ptr->transformations & PNG_GAMMA) != 0 ||
+       ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 &&
+        (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
+         png_gamma_significant(png_ptr->screen_gamma) != 0)) ||
+        ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
+         (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
+          png_gamma_significant(png_ptr->screen_gamma) != 0
 #  ifdef PNG_READ_BACKGROUND_SUPPORTED
-            || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE
-               && png_gamma_significant(png_ptr->background_gamma))
+         || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE &&
+           png_gamma_significant(png_ptr->background_gamma) != 0)
 #  endif
-      )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA)
-         && png_gamma_significant(png_ptr->screen_gamma))
-      )
+        )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+       png_gamma_significant(png_ptr->screen_gamma) != 0))
    {
       png_build_gamma_table(png_ptr, png_ptr->bit_depth);
 
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
-      if (png_ptr->transformations & PNG_COMPOSE)
+      if ((png_ptr->transformations & PNG_COMPOSE) != 0)
       {
          /* Issue a warning about this combination: because RGB_TO_GRAY is
           * optimized to do the gamma transform if present yet do_background has
@@ -1580,11 +1580,11 @@ png_init_read_transformations(png_structrp png_ptr)
           * double-gamma-correction happens.  This is true in all versions of
           * libpng to date.
           */
-         if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+         if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
             png_warning(png_ptr,
                "libpng does not support gamma+background+rgb_to_gray");
 
-         if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+         if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0)
          {
             /* We don't get to here unless there is a tRNS chunk with non-opaque
              * entries - see the checking code at the start of this function.
@@ -1632,7 +1632,7 @@ png_init_read_transformations(png_structrp png_ptr)
                      break;
                }
 
-               if (png_gamma_significant(gs))
+               if (png_gamma_significant(gs) != 0)
                {
                   back.red = png_gamma_8bit_correct(png_ptr->background.red,
                       gs);
@@ -1649,7 +1649,7 @@ png_init_read_transformations(png_structrp png_ptr)
                   back.blue  = (png_byte)png_ptr->background.blue;
                }
 
-               if (png_gamma_significant(g))
+               if (png_gamma_significant(g) != 0)
                {
                   back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
                      g);
@@ -1743,11 +1743,11 @@ png_init_read_transformations(png_structrp png_ptr)
             g_sig = png_gamma_significant(g);
             gs_sig = png_gamma_significant(gs);
 
-            if (g_sig)
+            if (g_sig != 0)
                png_ptr->background_1.gray = png_gamma_correct(png_ptr,
                    png_ptr->background.gray, g);
 
-            if (gs_sig)
+            if (gs_sig != 0)
                png_ptr->background.gray = png_gamma_correct(png_ptr,
                    png_ptr->background.gray, gs);
 
@@ -1756,7 +1756,7 @@ png_init_read_transformations(png_structrp png_ptr)
                 (png_ptr->background.red != png_ptr->background.gray))
             {
                /* RGB or RGBA with color background */
-               if (g_sig)
+               if (g_sig != 0)
                {
                   png_ptr->background_1.red = png_gamma_correct(png_ptr,
                       png_ptr->background.red, g);
@@ -1768,7 +1768,7 @@ png_init_read_transformations(png_structrp png_ptr)
                       png_ptr->background.blue, g);
                }
 
-               if (gs_sig)
+               if (gs_sig != 0)
                {
                   png_ptr->background.red = png_gamma_correct(png_ptr,
                       png_ptr->background.red, gs);
@@ -1798,7 +1798,7 @@ png_init_read_transformations(png_structrp png_ptr)
 
       else
       /* Transformation does not include PNG_BACKGROUND */
-#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+#endif /* READ_BACKGROUND */
       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
          /* RGB_TO_GRAY needs to have non-gamma-corrected values! */
@@ -1828,11 +1828,11 @@ png_init_read_transformations(png_structrp png_ptr)
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
    else
 #endif
-#endif /* PNG_READ_GAMMA_SUPPORTED */
+#endif /* READ_GAMMA */
 
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
    /* No GAMMA transformation (see the hanging else 4 lines above) */
-   if ((png_ptr->transformations & PNG_COMPOSE) &&
+   if ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
        (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
    {
       int i;
@@ -1867,11 +1867,11 @@ png_init_read_transformations(png_structrp png_ptr)
 
       png_ptr->transformations &= ~PNG_COMPOSE;
    }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+#endif /* READ_BACKGROUND */
 
 #ifdef PNG_READ_SHIFT_SUPPORTED
-   if ((png_ptr->transformations & PNG_SHIFT) &&
-      !(png_ptr->transformations & PNG_EXPAND) &&
+   if ((png_ptr->transformations & PNG_SHIFT) != 0 &&
+       (png_ptr->transformations & PNG_EXPAND) == 0 &&
        (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
    {
       int i;
@@ -1913,7 +1913,7 @@ png_init_read_transformations(png_structrp png_ptr)
             png_ptr->palette[i].blue = (png_byte)component;
          }
    }
-#endif  /* PNG_READ_SHIFT_SUPPORTED */
+#endif  /* READ_SHIFT */
 }
 
 /* Modify the info structure to reflect the transformations.  The
@@ -1926,7 +1926,7 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
    png_debug(1, "in png_read_transform_info");
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
-   if (png_ptr->transformations & PNG_EXPAND)
+   if ((png_ptr->transformations & PNG_EXPAND) != 0)
    {
       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       {
@@ -1948,9 +1948,9 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
       }
       else
       {
-         if (png_ptr->num_trans)
+         if (png_ptr->num_trans != 0)
          {
-            if (png_ptr->transformations & PNG_EXPAND_tRNS)
+            if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
                info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
          }
          if (info_ptr->bit_depth < 8)
@@ -1966,7 +1966,7 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
    /* The following is almost certainly wrong unless the background value is in
     * the screen space!
     */
-   if (png_ptr->transformations & PNG_COMPOSE)
+   if ((png_ptr->transformations & PNG_COMPOSE) != 0)
       info_ptr->background = png_ptr->background;
 #endif
 
@@ -1987,12 +1987,12 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
    {
 #  ifdef PNG_READ_16BIT_SUPPORTED
 #     ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-         if (png_ptr->transformations & PNG_SCALE_16_TO_8)
+         if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
             info_ptr->bit_depth = 8;
 #     endif
 
 #     ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
-         if (png_ptr->transformations & PNG_16_TO_8)
+         if ((png_ptr->transformations & PNG_16_TO_8) != 0)
             info_ptr->bit_depth = 8;
 #     endif
 
@@ -2018,27 +2018,27 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
             CONFIGURATION ERROR: you must enable at least one 16 to 8 method
 #        endif
 #    endif
-#endif /* !READ_16BIT_SUPPORTED */
+#endif /* !READ_16BIT */
    }
 
 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
-   if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
       info_ptr->color_type = (png_byte)(info_ptr->color_type |
          PNG_COLOR_MASK_COLOR);
 #endif
 
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
       info_ptr->color_type = (png_byte)(info_ptr->color_type &
          ~PNG_COLOR_MASK_COLOR);
 #endif
 
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
-   if (png_ptr->transformations & PNG_QUANTIZE)
+   if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
    {
       if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
           (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
-          png_ptr->palette_lookup && info_ptr->bit_depth == 8)
+          png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8)
       {
          info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
       }
@@ -2046,29 +2046,31 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
 #endif
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
-   if (png_ptr->transformations & PNG_EXPAND_16 && info_ptr->bit_depth == 8 &&
-      info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
+   if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
+       info_ptr->bit_depth == 8 &&
+       info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
    {
       info_ptr->bit_depth = 16;
    }
 #endif
 
 #ifdef PNG_READ_PACK_SUPPORTED
-   if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
+   if ((png_ptr->transformations & PNG_PACK) != 0 &&
+       (info_ptr->bit_depth < 8))
       info_ptr->bit_depth = 8;
 #endif
 
    if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       info_ptr->channels = 1;
 
-   else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+   else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
       info_ptr->channels = 3;
 
    else
       info_ptr->channels = 1;
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
-   if (png_ptr->transformations & PNG_STRIP_ALPHA)
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0)
    {
       info_ptr->color_type = (png_byte)(info_ptr->color_type &
          ~PNG_COLOR_MASK_ALPHA);
@@ -2076,25 +2078,25 @@ png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
    }
 #endif
 
-   if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+   if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
       info_ptr->channels++;
 
 #ifdef PNG_READ_FILLER_SUPPORTED
    /* STRIP_ALPHA and FILLER allowed:  MASK_ALPHA bit stripped above */
-   if ((png_ptr->transformations & PNG_FILLER) &&
-       ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
-       (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
+   if ((png_ptr->transformations & PNG_FILLER) != 0 &&
+       (info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
+       info_ptr->color_type == PNG_COLOR_TYPE_GRAY))
    {
       info_ptr->channels++;
       /* If adding a true alpha channel not just filler */
-      if (png_ptr->transformations & PNG_ADD_ALPHA)
+      if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0)
          info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
    }
 #endif
 
 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
 defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
-   if (png_ptr->transformations & PNG_USER_TRANSFORM)
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
    {
       if (info_ptr->bit_depth < png_ptr->user_transform_depth)
          info_ptr->bit_depth = png_ptr->user_transform_depth;
@@ -2118,7 +2120,7 @@ defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
    png_ptr->info_rowbytes = info_ptr->rowbytes;
 
 #ifndef PNG_READ_EXPAND_SUPPORTED
-   if (png_ptr)
+   if (png_ptr != NULL)
       return;
 #endif
 }
@@ -2245,7 +2247,7 @@ png_do_unshift(png_row_infop row_info, png_bytep row,
       int channels = 0;
       int bit_depth = row_info->bit_depth;
 
-      if (color_type & PNG_COLOR_MASK_COLOR)
+      if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
       {
          shift[channels++] = bit_depth - sig_bits->red;
          shift[channels++] = bit_depth - sig_bits->green;
@@ -2257,7 +2259,7 @@ png_do_unshift(png_row_infop row_info, png_bytep row,
          shift[channels++] = bit_depth - sig_bits->gray;
       }
 
-      if (color_type & PNG_COLOR_MASK_ALPHA)
+      if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
       {
          shift[channels++] = bit_depth - sig_bits->alpha;
       }
@@ -2277,7 +2279,7 @@ png_do_unshift(png_row_infop row_info, png_bytep row,
                have_shift = 1;
          }
 
-         if (!have_shift)
+         if (have_shift == 0)
             return;
       }
 
@@ -2671,7 +2673,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
    {
       if (row_info->bit_depth == 8)
       {
-         if (flags & PNG_FLAG_FILLER_AFTER)
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
          {
             /* This changes the data from G to GX */
             png_bytep sp = row + (png_size_t)row_width;
@@ -2706,7 +2708,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
 #ifdef PNG_READ_16BIT_SUPPORTED
       else if (row_info->bit_depth == 16)
       {
-         if (flags & PNG_FLAG_FILLER_AFTER)
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
          {
             /* This changes the data from GG to GGXX */
             png_bytep sp = row + (png_size_t)row_width * 2;
@@ -2748,7 +2750,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
    {
       if (row_info->bit_depth == 8)
       {
-         if (flags & PNG_FLAG_FILLER_AFTER)
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
          {
             /* This changes the data from RGB to RGBX */
             png_bytep sp = row + (png_size_t)row_width * 3;
@@ -2787,7 +2789,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
 #ifdef PNG_READ_16BIT_SUPPORTED
       else if (row_info->bit_depth == 16)
       {
-         if (flags & PNG_FLAG_FILLER_AFTER)
+         if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
          {
             /* This changes the data from RRGGBB to RRGGBBXX */
             png_bytep sp = row + (png_size_t)row_width * 6;
@@ -2848,7 +2850,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
    png_debug(1, "in png_do_gray_to_rgb");
 
    if (row_info->bit_depth >= 8 &&
-       !(row_info->color_type & PNG_COLOR_MASK_COLOR))
+       (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0)
    {
       if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
       {
@@ -2986,8 +2988,8 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
 
    png_debug(1, "in png_do_rgb_to_gray");
 
-   if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) &&
-       (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 &&
+       (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
    {
       PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
       PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
@@ -3038,7 +3040,7 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
                   *(dp++) = red;
                }
 
-               if (have_alpha)
+               if (have_alpha != 0)
                   *(dp++) = *(sp++);
             }
          }
@@ -3067,7 +3069,7 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
                else
                   *(dp++) = red;
 
-               if (have_alpha)
+               if (have_alpha != 0)
                   *(dp++) = *(sp++);
             }
          }
@@ -3086,15 +3088,15 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
             {
                png_uint_16 red, green, blue, w;
 
-               red   = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-               green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-               blue  = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               red   = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
+               green = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
+               blue  = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
 
                if (red == green && red == blue)
                {
                   if (png_ptr->gamma_16_table != NULL)
-                     w = png_ptr->gamma_16_table[(red&0xff)
-                         >> png_ptr->gamma_shift][red>>8];
+                     w = png_ptr->gamma_16_table[(red & 0xff)
+                         >> png_ptr->gamma_shift][red >> 8];
 
                   else
                      w = red;
@@ -3119,7 +3121,7 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
                *(dp++) = (png_byte)((w>>8) & 0xff);
                *(dp++) = (png_byte)(w & 0xff);
 
-               if (have_alpha)
+               if (have_alpha != 0)
                {
                   *(dp++) = *(sp++);
                   *(dp++) = *(sp++);
@@ -3137,9 +3139,9 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
             {
                png_uint_16 red, green, blue, gray16;
 
-               red   = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-               green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
-               blue  = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2;
+               red   = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
+               green = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
+               blue  = (png_uint_16)(((*(sp)) << 8) | *(sp + 1)); sp += 2;
 
                if (red != green || red != blue)
                   rgb_error |= 1;
@@ -3150,10 +3152,10 @@ png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
                 */
                gray16  = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
                   15);
-               *(dp++) = (png_byte)((gray16>>8) & 0xff);
+               *(dp++) = (png_byte)((gray16 >> 8) & 0xff);
                *(dp++) = (png_byte)(gray16 & 0xff);
 
-               if (have_alpha)
+               if (have_alpha != 0)
                {
                   *(dp++) = *(sp++);
                   *(dp++) = *(sp++);
@@ -3221,7 +3223,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                         *sp = (png_byte)(tmp & 0xff);
                      }
 
-                     if (!shift)
+                     if (shift == 0)
                      {
                         shift = 7;
                         sp++;
@@ -3260,7 +3262,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 6;
                            sp++;
@@ -3286,7 +3288,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 6;
                            sp++;
@@ -3326,7 +3328,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 4;
                            sp++;
@@ -3352,7 +3354,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 4;
                            sp++;
@@ -3605,7 +3607,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                         v = gamma_to_1[*sp];
                         png_composite(w, v, a, png_ptr->background_1.gray);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_from_1[w];
                         *sp = w;
                      }
@@ -3662,7 +3664,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                         g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
                         png_composite_16(v, g, a, png_ptr->background_1.gray);
-                        if (optimize)
+                        if (optimize != 0)
                            w = v;
                         else
                            w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
@@ -3736,17 +3738,17 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                         v = gamma_to_1[*sp];
                         png_composite(w, v, a, png_ptr->background_1.red);
-                        if (!optimize) w = gamma_from_1[w];
+                        if (optimize == 0) w = gamma_from_1[w];
                         *sp = w;
 
                         v = gamma_to_1[*(sp + 1)];
                         png_composite(w, v, a, png_ptr->background_1.green);
-                        if (!optimize) w = gamma_from_1[w];
+                        if (optimize == 0) w = gamma_from_1[w];
                         *(sp + 1) = w;
 
                         v = gamma_to_1[*(sp + 2)];
                         png_composite(w, v, a, png_ptr->background_1.blue);
-                        if (!optimize) w = gamma_from_1[w];
+                        if (optimize == 0) w = gamma_from_1[w];
                         *(sp + 2) = w;
                      }
                   }
@@ -3828,7 +3830,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                         v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
                         png_composite_16(w, v, a, png_ptr->background_1.red);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
                                 8];
                         *sp = (png_byte)((w >> 8) & 0xff);
@@ -3836,7 +3838,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                         v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
                         png_composite_16(w, v, a, png_ptr->background_1.green);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
                                 8];
 
@@ -3845,7 +3847,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
                         v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
                         png_composite_16(w, v, a, png_ptr->background_1.blue);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
                                 8];
 
@@ -3910,7 +3912,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
       }
    }
 }
-#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_READ_ALPHA_MODE_SUPPORTED */
+#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
 /* Gamma correct the image, avoiding the alpha channel.  Make sure
@@ -4127,7 +4129,7 @@ png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
 
    png_debug(1, "in png_do_encode_alpha");
 
-   if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+   if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
    {
       if (row_info->bit_depth == 8)
       {
@@ -4353,7 +4355,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
    {
       if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
       {
-         unsigned int gray = trans_color ? trans_color->gray : 0;
+         unsigned int gray = trans_color != NULL ? trans_color->gray : 0;
 
          if (row_info->bit_depth < 8)
          {
@@ -4497,7 +4499,8 @@ png_do_expand(png_row_infop row_info, png_bytep row,
                row_width);
          }
       }
-      else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_color)
+      else if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
+          trans_color != NULL)
       {
          if (row_info->bit_depth == 8)
          {
@@ -4688,7 +4691,7 @@ png_do_quantize(png_row_infop row_info, png_bytep row,
       }
    }
 }
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#endif /* READ_QUANTIZE */
 
 /* Transform the row.  The order of transformations is significant,
  * and is very touchy.  If you add a transformation, take care to
@@ -4715,7 +4718,7 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
     * demand, if necessary.
     */
    if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
-      !(png_ptr->flags & PNG_FLAG_ROW_INIT))
+       (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
    {
       /* Application has failed to call either png_read_start_image() or
        * png_read_update_info() after setting transforms that expand pixels.
@@ -4725,7 +4728,7 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
    }
 
 #ifdef PNG_READ_EXPAND_SUPPORTED
-   if (png_ptr->transformations & PNG_EXPAND)
+   if ((png_ptr->transformations & PNG_EXPAND) != 0)
    {
       if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
       {
@@ -4735,8 +4738,8 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 
       else
       {
-         if (png_ptr->num_trans &&
-             (png_ptr->transformations & PNG_EXPAND_tRNS))
+         if (png_ptr->num_trans != 0 &&
+             (png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
             png_do_expand(row_info, png_ptr->row_buf + 1,
                 &(png_ptr->trans_color));
 
@@ -4748,22 +4751,22 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 #endif
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
-   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
-      !(png_ptr->transformations & PNG_COMPOSE) &&
-      (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
-      row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) == 0 &&
+       (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+       row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
       png_do_strip_channel(row_info, png_ptr->row_buf + 1,
          0 /* at_start == false, because SWAP_ALPHA happens later */);
 #endif
 
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
-   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+   if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
    {
       int rgb_error =
           png_do_rgb_to_gray(png_ptr, row_info,
               png_ptr->row_buf + 1);
 
-      if (rgb_error)
+      if (rgb_error != 0)
       {
          png_ptr->rgb_to_gray_status=1;
          if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
@@ -4812,22 +4815,22 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
    /* If gray -> RGB, do so now only if background is non-gray; else do later
     * for performance reasons
     */
-   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
-       !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0)
       png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
 #endif
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
-   if (png_ptr->transformations & PNG_COMPOSE)
+   if ((png_ptr->transformations & PNG_COMPOSE) != 0)
       png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
 #endif
 
 #ifdef PNG_READ_GAMMA_SUPPORTED
-   if ((png_ptr->transformations & PNG_GAMMA) &&
+   if ((png_ptr->transformations & PNG_GAMMA) != 0 &&
 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
       /* Because RGB_TO_GRAY does the gamma transform. */
-      !(png_ptr->transformations & PNG_RGB_TO_GRAY) &&
+      (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 &&
 #endif
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
    defined(PNG_READ_ALPHA_MODE_SUPPORTED)
@@ -4836,7 +4839,7 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
        */
        !((png_ptr->transformations & PNG_COMPOSE) &&
        ((png_ptr->num_trans != 0) ||
-       (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
+       (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) &&
 #endif
       /* Because png_init_read_transformations transforms the palette, unless
        * RGB_TO_GRAY will do the transform.
@@ -4846,22 +4849,22 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 #endif
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
-   if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
-      (png_ptr->transformations & PNG_COMPOSE) &&
-      (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
-      row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+   if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
+       (png_ptr->transformations & PNG_COMPOSE) != 0 &&
+       (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+       row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
       png_do_strip_channel(row_info, png_ptr->row_buf + 1,
-         0 /* at_start == false, because SWAP_ALPHA happens later */);
+          0 /* at_start == false, because SWAP_ALPHA happens later */);
 #endif
 
 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
-   if ((png_ptr->transformations & PNG_ENCODE_ALPHA) &&
-      (row_info->color_type & PNG_COLOR_MASK_ALPHA))
+   if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
+       (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
       png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
 #endif
 
 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-   if (png_ptr->transformations & PNG_SCALE_16_TO_8)
+   if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
       png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
 #endif
 
@@ -4870,12 +4873,12 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
     * by putting the 'scale' option first if the app asks for scale (either by
     * calling the API or in a TRANSFORM flag) this is what happens.
     */
-   if (png_ptr->transformations & PNG_16_TO_8)
+   if ((png_ptr->transformations & PNG_16_TO_8) != 0)
       png_do_chop(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_QUANTIZE_SUPPORTED
-   if (png_ptr->transformations & PNG_QUANTIZE)
+   if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
    {
       png_do_quantize(row_info, png_ptr->row_buf + 1,
           png_ptr->palette_lookup, png_ptr->quantize_index);
@@ -4883,7 +4886,7 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
       if (row_info->rowbytes == 0)
          png_error(png_ptr, "png_do_quantize returned rowbytes=0");
    }
-#endif /* PNG_READ_QUANTIZE_SUPPORTED */
+#endif /* READ_QUANTIZE */
 
 #ifdef PNG_READ_EXPAND_16_SUPPORTED
    /* Do the expansion now, after all the arithmetic has been done.  Notice
@@ -4891,35 +4894,35 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
     * is efficient (particularly true in the case of gamma correction, where
     * better accuracy results faster!)
     */
-   if (png_ptr->transformations & PNG_EXPAND_16)
+   if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
       png_do_expand_16(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
    /* NOTE: moved here in 1.5.4 (from much later in this list.) */
-   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
-       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
+       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0)
       png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_INVERT_SUPPORTED
-   if (png_ptr->transformations & PNG_INVERT_MONO)
+   if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
       png_do_invert(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
-   if (png_ptr->transformations & PNG_INVERT_ALPHA)
+   if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
       png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_SHIFT_SUPPORTED
-   if (png_ptr->transformations & PNG_SHIFT)
+   if ((png_ptr->transformations & PNG_SHIFT) != 0)
       png_do_unshift(row_info, png_ptr->row_buf + 1,
           &(png_ptr->shift));
 #endif
 
 #ifdef PNG_READ_PACK_SUPPORTED
-   if (png_ptr->transformations & PNG_PACK)
+   if ((png_ptr->transformations & PNG_PACK) != 0)
       png_do_unpack(row_info, png_ptr->row_buf + 1);
 #endif
 
@@ -4931,36 +4934,36 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 #endif
 
 #ifdef PNG_READ_BGR_SUPPORTED
-   if (png_ptr->transformations & PNG_BGR)
+   if ((png_ptr->transformations & PNG_BGR) != 0)
       png_do_bgr(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_PACKSWAP_SUPPORTED
-   if (png_ptr->transformations & PNG_PACKSWAP)
+   if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
       png_do_packswap(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_FILLER_SUPPORTED
-   if (png_ptr->transformations & PNG_FILLER)
+   if ((png_ptr->transformations & PNG_FILLER) != 0)
       png_do_read_filler(row_info, png_ptr->row_buf + 1,
           (png_uint_32)png_ptr->filler, png_ptr->flags);
 #endif
 
 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
-   if (png_ptr->transformations & PNG_SWAP_ALPHA)
+   if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
       png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
 #endif
 
 #ifdef PNG_READ_16BIT_SUPPORTED
 #ifdef PNG_READ_SWAP_SUPPORTED
-   if (png_ptr->transformations & PNG_SWAP_BYTES)
+   if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
       png_do_swap(row_info, png_ptr->row_buf + 1);
 #endif
 #endif
 
 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
-   if (png_ptr->transformations & PNG_USER_TRANSFORM)
-    {
+   if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
+   {
       if (png_ptr->read_user_transform_fn != NULL)
          (*(png_ptr->read_user_transform_fn)) /* User read transform function */
              (png_ptr,     /* png_ptr */
@@ -4973,10 +4976,10 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
                 /*  png_byte pixel_depth;    bits per pixel (depth*channels) */
              png_ptr->row_buf + 1);    /* start of pixel data for row */
 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
-      if (png_ptr->user_transform_depth)
+      if (png_ptr->user_transform_depth != 0)
          row_info->bit_depth = png_ptr->user_transform_depth;
 
-      if (png_ptr->user_transform_channels)
+      if (png_ptr->user_transform_channels != 0)
          row_info->channels = png_ptr->user_transform_channels;
 #endif
       row_info->pixel_depth = (png_byte)(row_info->bit_depth *
@@ -4987,5 +4990,5 @@ png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
 #endif
 }
 
-#endif /* PNG_READ_TRANSFORMS_SUPPORTED */
-#endif /* PNG_READ_SUPPORTED */
+#endif /* READ_TRANSFORMS */
+#endif /* READ */
-- 
cgit v1.2.3