[libpng16] Fixed bug recently introduced in png_set_PLTE() that uses png_ptr

not info_ptr.

ANNOUNCE

-Libpng 1.6.20beta02 - November 22, 2015
+Libpng 1.6.20beta02 - November 23, 2015
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -30,6 +30,8 @@ Version 1.6.20beta01 [November 20, 2015]
     png_handle_pCAL() (Bug report by John Regehr).
 
 Version 1.6.20beta02 [(PENDING RELEASE)]
+  Fixed bug recently introduced in png_set_PLTE() that uses png_ptr
+    not info_ptr.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -5419,6 +5419,8 @@ Version 1.6.20beta01 [November 20, 2015]
     png_handle_pCAL() (Bug report by John Regehr).
 
 Version 1.6.20beta02 [(PENDING RELEASE)]
+  Fixed bug recently introduced in png_set_PLTE() that uses png_ptr
+    not info_ptr.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

pngset.c

@@ -520,8 +520,8 @@ png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr,
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
-   max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
-      (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
+   max_palette_length = (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
+      (1 << info_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
 
    if (num_palette < 0 || num_palette > (int) max_palette_length)
    {