Update bundled libpng to last upstream version 1.6.54

1 files changed, 29 insertions, 26 deletions

diff --git a/png/pngwrite.c b/png/pngwrite.c
index 35a5d17b6..362a8c3e1 100644
--- a/png/pngwrite.c
+++ b/png/pngwrite.c
@@ -1,6 +1,6 @@
 /* pngwrite.c - general routines to write a PNG file
  *
- * Copyright (c) 2018-2025 Cosmin Truta
+ * Copyright (c) 2018-2026 Cosmin Truta
  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
  * Copyright (c) 1996-1997 Andreas Dilger
  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
@@ -542,7 +542,8 @@ png_convert_from_time_t(png_timep ptime, time_t ttime)
 /* Initialize png_ptr structure, and allocate any memory needed */
 PNG_FUNCTION(png_structp,PNGAPI
 png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
-    png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
+    png_error_ptr error_fn, png_error_ptr warn_fn),
+    PNG_ALLOCATED)
 {
 #ifndef PNG_USER_MEM_SUPPORTED
    png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
@@ -556,7 +557,8 @@ png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
 PNG_FUNCTION(png_structp,PNGAPI
 png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
     png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
-    png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
+    png_malloc_ptr malloc_fn, png_free_ptr free_fn),
+    PNG_ALLOCATED)
 {
    png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
        error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
@@ -1376,8 +1378,8 @@ png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
 
 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
 void PNGAPI
-png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
-    write_user_transform_fn)
+png_set_write_user_transform_fn(png_structrp png_ptr,
+    png_user_transform_ptr write_user_transform_fn)
 {
    png_debug(1, "in png_set_write_user_transform_fn");
 
@@ -1393,7 +1395,7 @@ png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
 #ifdef PNG_INFO_IMAGE_SUPPORTED
 void PNGAPI
 png_write_png(png_structrp png_ptr, png_inforp info_ptr,
-    int transforms, voidp params)
+    int transforms, png_voidp params)
 {
    png_debug(1, "in png_write_png");
 
@@ -1558,18 +1560,20 @@ png_image_write_init(png_imagep image)
 /* Arguments to png_image_write_main: */
 typedef struct
 {
-   /* Arguments: */
-   png_imagep      image;
+   /* Arguments */
+   png_imagep image;
    png_const_voidp buffer;
-   png_int_32      row_stride;
+   png_int_32 row_stride;
    png_const_voidp colormap;
-   int             convert_to_8bit;
-   /* Local variables: */
+   int convert_to_8bit;
+
+   /* Instance variables */
    png_const_voidp first_row;
-   ptrdiff_t       row_bytes;
-   png_voidp       local_row;
+   png_voidp local_row;
+   ptrdiff_t row_step;
+
    /* Byte count for memory writing */
-   png_bytep        memory;
+   png_bytep memory;
    png_alloc_size_t memory_bytes; /* not used for STDIO */
    png_alloc_size_t output_bytes; /* running total */
 } png_image_write_control;
@@ -1676,7 +1680,7 @@ png_write_image_16bit(png_voidp argument)
       }
 
       png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row));
-      input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+      input_row += display->row_step / 2;
    }
 
    return 1;
@@ -1802,7 +1806,7 @@ png_write_image_8bit(png_voidp argument)
 
          png_write_row(png_ptr, png_voidcast(png_const_bytep,
              display->local_row));
-         input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+         input_row += display->row_step / 2;
       } /* while y */
    }
 
@@ -1827,7 +1831,7 @@ png_write_image_8bit(png_voidp argument)
          }
 
          png_write_row(png_ptr, output_row);
-         input_row += (png_uint_16)display->row_bytes/(sizeof (png_uint_16));
+         input_row += display->row_step / 2;
       }
    }
 
@@ -2143,16 +2147,16 @@ png_image_write_main(png_voidp argument)
 
    {
       png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
-      ptrdiff_t row_bytes = display->row_stride;
+      ptrdiff_t row_step = display->row_stride;
 
       if (linear != 0)
-         row_bytes *= (sizeof (png_uint_16));
+         row_step *= 2;
 
-      if (row_bytes < 0)
-         row += (image->height-1) * (-row_bytes);
+      if (row_step < 0)
+         row += (image->height-1) * (-row_step);
 
       display->first_row = row;
-      display->row_bytes = row_bytes;
+      display->row_step = row_step;
    }
 
    /* Apply 'fast' options if the flag is set. */
@@ -2173,8 +2177,7 @@ png_image_write_main(png_voidp argument)
     * before it is written.  This only applies when the input is 16-bit and
     * either there is an alpha channel or it is converted to 8-bit.
     */
-   if ((linear != 0 && alpha != 0 ) ||
-       (colormap == 0 && display->convert_to_8bit != 0))
+   if (linear != 0 && (alpha != 0 || display->convert_to_8bit != 0))
    {
       png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr,
           png_get_rowbytes(png_ptr, info_ptr)));
@@ -2200,13 +2203,13 @@ png_image_write_main(png_voidp argument)
    else
    {
       png_const_bytep row = png_voidcast(png_const_bytep, display->first_row);
-      ptrdiff_t row_bytes = display->row_bytes;
+      ptrdiff_t row_step = display->row_step;
       png_uint_32 y = image->height;
 
       for (; y > 0; --y)
       {
          png_write_row(png_ptr, row);
-         row += row_bytes;
+         row += row_step;
       }
    }