[libpng16] Restore info_ptr members that were deleted by the previous

patch; they are needed by png_set_IHDR() for both read and write.  Fix
some ifdefs that caused the contrib/pngminim/ applications to not compile.

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.0beta27 - July 14, 2012
+ * libpng version 1.6.0beta27 - August 10, 2012
  * Copyright (c) 1998-2012 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.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.0beta27 - July 14, 2012: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.0beta27 - August 10, 2012: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -198,7 +198,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.0beta27, July 14, 2012, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.0beta27, August 10, 2012, are
  * Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -310,7 +310,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    July 14, 2012
+ *    August 10, 2012
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -378,7 +378,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.6.0beta27"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.0beta27 - July 14, 2012\n"
+     " libpng version 1.6.0beta27 - August 10, 2012\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -1034,7 +1034,7 @@ PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
     png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
 #  define png_jmpbuf(png_ptr) \
-      (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
+      (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
 #else
 #  define png_jmpbuf(png_ptr) \
       (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
@@ -2008,9 +2008,11 @@ PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
     png_inforp info_ptr, png_bytepp row_pointers));
 #endif
 
+#ifdef PNG_READ_SUPPORTED
 /* Returns number of color channels in image. */
 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
     png_const_inforp info_ptr));
+#endif
 
 #ifdef PNG_EASY_ACCESS_SUPPORTED
 /* Returns image width in pixels. */
@@ -2067,9 +2069,11 @@ PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
 
 #endif /* PNG_EASY_ACCESS_SUPPORTED */
 
+#ifdef PNG_READ_SUPPORTED
 /* Returns pointer to signature string read from PNG header */
 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
     png_const_inforp info_ptr));
+#endif
 
 #ifdef PNG_bKGD_SUPPORTED
 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,

pngget.c

@@ -422,6 +422,8 @@ png_get_pHYs_dpi(png_const_structrp png_ptr, png_const_inforp info_ptr,
 
 #endif  /* PNG_EASY_ACCESS_SUPPORTED */
 
+
+#ifdef PNG_READ_SUPPORTED
 png_byte PNGAPI
 png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
 {
@@ -439,6 +441,7 @@ png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
 
    return (NULL);
 }
+#endif
 
 #ifdef PNG_bKGD_SUPPORTED
 png_uint_32 PNGAPI

pnginfo.h

@@ -55,7 +55,7 @@
 
 struct png_info_def
 {
-   /* the following are necessary for every PNG file */
+   /* The following are necessary for every PNG file */
    png_uint_32 width;  /* width of image in pixels (from IHDR) */
    png_uint_32 height; /* height of image in pixels (from IHDR) */
    png_uint_32 valid;  /* valid chunk data (see PNG_INFO_ below) */
@@ -70,13 +70,10 @@ struct png_info_def
    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
 
-#ifdef PNG_READ_SUPPORTED
-   /* The following is informational only on read, and not used on writes. */
    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
    png_byte pixel_depth;    /* number of bits per pixel */
    png_byte spare_byte;     /* to align the data, and for future use */
    png_byte signature[8];   /* magic bytes read by libpng from start of file */
-#endif
 
    /* The rest of the data is optional.  If you are reading, check the
     * valid field to see if the information in these are valid.  If you

pngrutil.c

@@ -312,8 +312,16 @@ png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
 
       else if (warn < 2) /* else silent */
       {
-         (warn ? png_chunk_warning : png_chunk_error)(png_ptr,
+#ifdef PNG_WARNINGS_SUPPORTED
-            "insufficient memory to read chunk");
+         if (warn)
+             png_chunk_warning(png_ptr, "insufficient memory to read chunk");
+         else
+#endif
+         {
+#ifdef PNG_ERROR_TEXT_SUPPORTED
+             png_chunk_error(png_ptr, "insufficient memory to read chunk");
+#endif
+         }
       }
    }
 

pngset.c

@@ -1297,7 +1297,7 @@ png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
       }
 #  endif
 
-#  ifdef PNG_WRITE_SUPPORTED
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
       if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
       {
          if (png_ptr->zowner != 0)

pngwrite.c

@@ -872,7 +872,9 @@ png_write_destroy(png_structrp png_ptr)
       deflateEnd(&png_ptr->zstream);
 
    /* Free our memory.  png_free checks NULL for us. */
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
    png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
+#endif
    png_free(png_ptr, png_ptr->row_buf);
 #ifdef PNG_WRITE_FILTER_SUPPORTED
    png_free(png_ptr, png_ptr->prev_row);

pngwutil.c

@@ -1033,8 +1033,10 @@ png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
          png_ptr->zbuffer_list->next = NULL;
       }
 
+#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
       else
          png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
+#endif
 
       /* It is a terminal error if we can't claim the zstream. */
       if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)