windowscodecs: Fixed loading png from streams.

dlls/windowscodecs/pngformat.c

@@ -774,11 +774,12 @@ static HRESULT WINAPI PngDecoder_Initialize(IWICBitmapDecoder *iface, IStream *p
 
     /* Find the metadata chunks in the file. */
     seek.QuadPart = 8;
-    hr = IStream_Seek(pIStream, seek, STREAM_SEEK_SET, &chunk_start);
-    if (FAILED(hr)) goto end;
 
     do
     {
+        hr = IStream_Seek(pIStream, seek, STREAM_SEEK_SET, &chunk_start);
+        if (FAILED(hr)) goto end;
+
         hr = read_png_chunk(pIStream, chunk_type, NULL, &chunk_size);
         if (FAILED(hr)) goto end;
 
@@ -816,8 +817,6 @@ static HRESULT WINAPI PngDecoder_Initialize(IWICBitmapDecoder *iface, IStream *p
         }
 
         seek.QuadPart = chunk_start.QuadPart + chunk_size + 12; /* skip data and CRC */
-        hr = IStream_Seek(pIStream, seek, STREAM_SEEK_SET, &chunk_start);
-        if (FAILED(hr)) goto end;
     } while (memcmp(chunk_type, "IEND", 4));
 
     This->stream = pIStream;

dlls/windowscodecs/tests/pngformat.c

@@ -306,7 +306,7 @@ static IWICBitmapDecoder *create_decoder(const void *image_data, UINT image_size
 
     zero.QuadPart = 0;
     IStream_Seek (stream, zero, STREAM_SEEK_CUR, &pos);
-    todo_wine ok(pos.QuadPart < image_size, "seek beyond the end of stream: %x%08x >= %x\n",
+    ok(pos.QuadPart < image_size, "seek beyond the end of stream: %x%08x >= %x\n",
        (UINT)(pos.QuadPart >> 32), (UINT)pos.QuadPart, image_size);
 
     refcount = IStream_Release(stream);