CogDis: Battle background not shown in web player

[Ghabry]

Name of the game: Mother Cognitive Dissonance

Player platform: Web

Describe the issue in detail and how to reproduce it:

Start a battle. The background is missing due to async error.

[Ghabry]

Not tested yet but the fix should be simply using two request_id variables as the request does not fire the callback when the request gets overwritten.

diff --git a/src/background.cpp b/src/background.cpp
index d18bbfdc..30282818 100644
--- a/src/background.cpp
+++ b/src/background.cpp
@@ -35,7 +35,7 @@ Background::Background(const std::string& name) : Drawable(Priority_Background)
        if (!name.empty()) {
                FileRequestAsync* request = AsyncHandler::RequestFile("Backdrop", name);
                request->SetGraphicFile(true);
-               request_id = request->Bind(&Background::OnBackgroundGraphicReady, this);
+               bg_request_id = request->Bind(&Background::OnBackgroundGraphicReady, this);
                request->Start();
        }
 }
@@ -55,7 +55,7 @@ Background::Background(int terrain_id) : Drawable(Priority_Background)
        if (terrain->background_type == lcf::rpg::Terrain::BGAssociation_background && !terrain->background_name.empty()) {
                FileRequestAsync* request = AsyncHandler::RequestFile("Backdrop", terrain->background_name);
                request->SetGraphicFile(true);
-               request_id = request->Bind(&Background::OnBackgroundGraphicReady, this);
+               bg_request_id = request->Bind(&Background::OnBackgroundGraphicReady, this);
                request->Start();
                return;
        }
@@ -64,7 +64,7 @@ Background::Background(int terrain_id) : Drawable(Priority_Background)
        if (!terrain->background_a_name.empty()) {
                FileRequestAsync* request = AsyncHandler::RequestFile("Frame", terrain->background_a_name);
                request->SetGraphicFile(true);
-               request_id = request->Bind(&Background::OnBackgroundGraphicReady, this);
+               bg_request_id = request->Bind(&Background::OnBackgroundGraphicReady, this);
                request->Start();

                bg_hscroll = terrain->background_a_scrollh ? terrain->background_a_scrollh_speed : 0;
@@ -74,7 +74,7 @@ Background::Background(int terrain_id) : Drawable(Priority_Background)
        if (terrain->background_b && !terrain->background_b_name.empty()) {
                FileRequestAsync* request = AsyncHandler::RequestFile("Frame", terrain->background_b_name);
                request->SetGraphicFile(true);
-               request_id = request->Bind(&Background::OnForegroundFrameGraphicReady, this);
+               fg_request_id = request->Bind(&Background::OnForegroundFrameGraphicReady, this);
                request->Start();

                fg_hscroll = terrain->background_b_scrollh ? terrain->background_b_scrollh_speed : 0;
diff --git a/src/background.h b/src/background.h
index f8814871..1885d532 100644
--- a/src/background.h
+++ b/src/background.h
@@ -55,7 +55,8 @@ private:
        int fg_x = 0;
        int fg_y = 0;

-       FileRequestBinding request_id;
+       FileRequestBinding fg_request_id;
+       FileRequestBinding bg_request_id;
 };

 inline Tone Background::GetTone() const {