--- libpng-1.4.12.old/png.c
+++ libpng-1.4.12/png.c
@@ -19,6 +19,38 @@
 /* Generate a compiler error if there is an old png.h in the search path. */
 typedef version_1_4_12 Your_png_h_is_not_version_1_4_12;
 
+//--------------------------------------------------------------------
+
+#ifdef PNG_READ_SUPPORTED
+#undef png_check_sig
+
+int PNGAPI
+png_check_sig (png_bytep sig, int num)
+{
+  return ((int) !png_sig_cmp (sig, (png_size_t) 0, (png_size_t) num));
+}
+#endif
+
+/* Read the data from whatever input you are using.  The default routine
+ * reads from a file pointer.  Note that this routine sometimes gets called
+ * with very small lengths, so you should implement some kind of simple
+ * buffering if you are using unbuffered reads.  This should never be asked
+ * to read more then 64K on a 16 bit machine.
+ */
+
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
+png_read_data (png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   if (png_ptr->read_data_fn != NULL)
+      (*(png_ptr->read_data_fn)) (png_ptr, data, length);
+   else
+      png_error (png_ptr, "Call to NULL read function");
+}
+#endif
+
+//--------------------------------------------------------------------
+
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
  * stream we can set num_bytes = 8 so that libpng will not attempt to read
--- libpng-1.4.12.old/png.h
+++ libpng-1.4.12/png.h
@@ -1520,6 +1520,14 @@
 PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
    int num_bytes));
 
+/* Replacement for legacy "libpng" 1.2.X functions */
+extern PNG_EXPORT (int, png_check_sig)
+    PNGARG ((png_bytep, int));
+extern PNG_EXPORT (void, png_set_gray_1_2_4_to_8)
+    PNGARG ((png_structp));
+extern PNG_EXPORT (void, png_read_data)
+    PNGARG ((png_structp, png_bytep, png_size_t));
+
 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
  * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
  * signature, and non-zero otherwise.  Having num_to_check == 0 or
--- libpng-1.4.12.old/pngpriv.h
+++ libpng-1.4.12/pngpriv.h
@@ -305,10 +305,6 @@
 /* Read the chunk header (length + type name) */
 PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
 
-/* Read data from whatever input you are using into the "data" buffer */
-PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
-   png_size_t length));
-
 /* Read bytes into buf, and update png_ptr->crc */
 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
    png_size_t length));
--- libpng-1.4.12.old/pngrio.c
+++ libpng-1.4.12/pngrio.c
@@ -23,23 +23,6 @@
 #ifdef PNG_READ_SUPPORTED
 #include "pngpriv.h"
 
-/* Read the data from whatever input you are using.  The default routine
- * reads from a file pointer.  Note that this routine sometimes gets called
- * with very small lengths, so you should implement some kind of simple
- * buffering if you are using unbuffered reads.  This should never be asked
- * to read more then 64K on a 16 bit machine.
- */
-void /* PRIVATE */
-png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
-   png_debug1(4, "reading %d bytes", (int)length);
-
-   if (png_ptr->read_data_fn != NULL)
-      (*(png_ptr->read_data_fn))(png_ptr, data, length);
-   else
-      png_error(png_ptr, "Call to NULL read function");
-}
-
 #ifdef PNG_STDIO_SUPPORTED
 /* This is the function that does the actual reading of data.  If you are
  * not reading from a standard C stream, you should create a replacement
--- libpng-1.4.12.old/pngrtran.c
+++ libpng-1.4.12/pngrtran.c
@@ -21,6 +21,16 @@
 #ifdef PNG_READ_SUPPORTED
 #include "pngpriv.h"
 
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+/* Deprecated as of libpng-1.2.9 */
+
+void PNGAPI
+png_set_gray_1_2_4_to_8 (png_structp png_ptr)
+{
+   if (png_ptr == NULL) return;
+   png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+
 /* Set the action on getting a CRC error for an ancillary or critical chunk. */
 void PNGAPI
 png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)