Fix FTBFS due to png code

This closes Bug 595

digikam/kioslave/digikamthumbnail.cpp

@@ -370,7 +370,7 @@ TQImage kio_digikamthumbnailProtocol::loadPNG(const TQString& path)
     unsigned char buf[PNG_BYTES_TO_CHECK];
 
     fread(buf, 1, PNG_BYTES_TO_CHECK, f);
-    if (!png_check_sig(buf, PNG_BYTES_TO_CHECK))
+    if (png_sig_cmp(buf, 0, PNG_BYTES_TO_CHECK))
     {
         fclose(f);
         return qimage;
@@ -465,7 +465,7 @@ TQImage kio_digikamthumbnailProtocol::loadPNG(const TQString& path)
     {
         png_set_gray_to_rgb(png_ptr);
         if (png_get_bit_depth(png_ptr, info_ptr) < 8)
-            png_set_gray_1_2_4_to_8(png_ptr);
+            png_set_expand_gray_1_2_4_to_8(png_ptr);
     }
 
     int sizeOfUint = sizeof(unsigned int);

digikam/libs/dimg/loaders/pngloader.cpp

@@ -88,7 +88,7 @@ bool PNGLoader::load(const TQString& filePath, DImgLoaderObserver *observer)
     unsigned char buf[PNG_BYTES_TO_CHECK];
 
     fread(buf, 1, PNG_BYTES_TO_CHECK, f);
-    if (!png_check_sig(buf, PNG_BYTES_TO_CHECK))
+    if (png_sig_cmp(buf, 0, PNG_BYTES_TO_CHECK))
     {
         DDebug() << k_funcinfo << "Not a PNG image file." << endl;
         fclose(f);
@@ -252,7 +252,7 @@ bool PNGLoader::load(const TQString& filePath, DImgLoaderObserver *observer)
 #ifdef ENABLE_DEBUG_MESSAGES
                 DDebug() << "PNG in PNG_COLOR_TYPE_GRAY" << endl;
 #endif
-                png_set_gray_1_2_4_to_8(png_ptr);
+                png_set_expand_gray_1_2_4_to_8(png_ptr);
                 png_set_gray_to_rgb(png_ptr);
 
                 if (TQImage::systemByteOrder() == TQImage::LittleEndian)       // Intel

digikam/libs/greycstoration/CImg.h

@@ -29449,7 +29449,7 @@ namespace cimg_library {
         new_bit_depth = 8;
       }
       if (new_color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8){
-        png_set_gray_1_2_4_to_8(png_ptr);
+        png_set_expand_gray_1_2_4_to_8(png_ptr);
         new_bit_depth = 8;
       }
       if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))