windowscodecs: Implement PngDecoder_Block_GetReaderByIndex.

dlls/windowscodecs/pngformat.c

@@ -1062,8 +1062,51 @@ static HRESULT WINAPI PngDecoder_Block_GetCount(IWICMetadataBlockReader *iface,
 static HRESULT WINAPI PngDecoder_Block_GetReaderByIndex(IWICMetadataBlockReader *iface,
     UINT nIndex, IWICMetadataReader **ppIMetadataReader)
 {
-    FIXME("%p,%d,%p\n", iface, nIndex, ppIMetadataReader);
-    return E_NOTIMPL;
+    PngDecoder *This = impl_from_IWICMetadataBlockReader(iface);
+    HRESULT hr;
+    IWICComponentFactory* factory;
+    IWICStream* stream;
+
+    TRACE("%p,%d,%p\n", iface, nIndex, ppIMetadataReader);
+
+    if (nIndex >= This->metadata_count || !ppIMetadataReader)
+        return E_INVALIDARG;
+
+    if (!This->metadata_blocks[nIndex].reader)
+    {
+        hr = StreamImpl_Create(&stream);
+
+        if (SUCCEEDED(hr))
+        {
+            hr = IWICStream_InitializeFromIStreamRegion(stream, This->stream,
+                This->metadata_blocks[nIndex].ofs, This->metadata_blocks[nIndex].len);
+
+            if (SUCCEEDED(hr))
+                hr = ComponentFactory_CreateInstance(&IID_IWICComponentFactory, (void**)&factory);
+
+            if (SUCCEEDED(hr))
+            {
+                hr = IWICComponentFactory_CreateMetadataReaderFromContainer(factory,
+                    &GUID_ContainerFormatPng, NULL, WICMetadataCreationAllowUnknown,
+                    (IStream*)stream, &This->metadata_blocks[nIndex].reader);
+
+                IWICComponentFactory_Release(factory);
+            }
+
+            IWICStream_Release(stream);
+        }
+
+        if (FAILED(hr))
+        {
+            *ppIMetadataReader = NULL;
+            return hr;
+        }
+    }
+
+    *ppIMetadataReader = This->metadata_blocks[nIndex].reader;
+    IWICMetadataReader_AddRef(*ppIMetadataReader);
+
+    return S_OK;
 }
 
 static HRESULT WINAPI PngDecoder_Block_GetEnumerator(IWICMetadataBlockReader *iface,

dlls/windowscodecs/tests/metadata.c

@@ -960,19 +960,19 @@ static void test_metadata_png(void)
         }
 
         hr = IWICMetadataBlockReader_GetReaderByIndex(blockreader, 0, &reader);
-        todo_wine ok(hr == S_OK, "GetReaderByIndex failed, hr=%x\n", hr);
+        ok(hr == S_OK, "GetReaderByIndex failed, hr=%x\n", hr);
 
         if (SUCCEEDED(hr))
         {
             hr = IWICMetadataReader_GetMetadataFormat(reader, &containerformat);
             ok(hr == S_OK, "GetMetadataFormat failed, hr=%#x\n", hr);
-            ok(IsEqualGUID(&containerformat, &GUID_MetadataFormatChunktIME) ||
+            todo_wine ok(IsEqualGUID(&containerformat, &GUID_MetadataFormatChunktIME) ||
                broken(IsEqualGUID(&containerformat, &GUID_MetadataFormatUnknown)) /* Windows XP */,
                "unexpected container format\n");
 
             hr = IWICMetadataReader_GetCount(reader, &count);
             ok(hr == S_OK, "GetCount error %#x\n", hr);
-            ok(count == 6 || broken(count == 1) /* XP */, "expected 6, got %u\n", count);
+            todo_wine ok(count == 6 || broken(count == 1) /* XP */, "expected 6, got %u\n", count);
             if (count == 6)
                 compare_metadata(reader, td, count);