Detect flatpak rather than forcing xdg directories

the earlier patch was rather blunt and forced xdg directories in all
cases, this new solution is less ugly and will be easier to upstream.

detectflatpak.patch

@@ -0,0 +1,56 @@
+diff --git a/Source/Core/UICommon/UICommon.cpp b/Source/Core/UICommon/UICommon.cpp
+index cb857fd3c7..47a012c4f0 100644
+--- a/Source/Core/UICommon/UICommon.cpp
++++ b/Source/Core/UICommon/UICommon.cpp
+@@ -306,19 +306,45 @@ void SetUserDirectory(std::string custom_path)
+       user_path = home_path + DOLPHIN_DATA_DIR DIR_SEP;
+     }
+ #else
+-    // We are on a non-Apple and non-Android POSIX system, there are 4 cases:
+-    // 1. GetExeDirectory()/portable.txt exists
++    // We are on a non-Apple and non-Android POSIX system, there are 5 cases:
++    // 1. Running inside flatpak sandbox
++    //    -> Use XDG basedir
++    // 2. GetExeDirectory()/portable.txt exists
+     //    -> Use GetExeDirectory()/User
+-    // 2. $DOLPHIN_EMU_USERPATH is set
++    // 3. $DOLPHIN_EMU_USERPATH is set
+     //    -> Use $DOLPHIN_EMU_USERPATH
+-    // 3. ~/.dolphin-emu directory exists
++    // 4. ~/.dolphin-emu directory exists
+     //    -> Use ~/.dolphin-emu
+-    // 4. Default
++    // 5. Default
+     //    -> Use XDG basedir, see
+     //    http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
+     user_path = home_path + "." DOLPHIN_DATA_DIR DIR_SEP;
+     std::string exe_path = File::GetExeDirectory();
+-    if (File::Exists(exe_path + DIR_SEP "portable.txt"))
++    if (File::Exists(DIR_SEP ".flatpak-info"))
++    {
++      const char* data_home = getenv("XDG_DATA_HOME");
++      std::string data_path =
++          std::string(data_home && data_home[0] == '/' ? data_home :
++                                                         (home_path + ".local" DIR_SEP "share")) +
++          DIR_SEP DOLPHIN_DATA_DIR DIR_SEP;
++
++      const char* config_home = getenv("XDG_CONFIG_HOME");
++      std::string config_path =
++          std::string(config_home && config_home[0] == '/' ? config_home :
++                                                             (home_path + ".config")) +
++          DIR_SEP DOLPHIN_DATA_DIR DIR_SEP;
++
++      const char* cache_home = getenv("XDG_CACHE_HOME");
++      std::string cache_path =
++          std::string(cache_home && cache_home[0] == '/' ? cache_home : (home_path + ".cache")) +
++          DIR_SEP DOLPHIN_DATA_DIR DIR_SEP;
++
++      File::SetUserPath(D_USER_IDX, data_path);
++      File::SetUserPath(D_CONFIG_IDX, config_path);
++      File::SetUserPath(D_CACHE_IDX, cache_path);
++      return;
++    }
++    else if (File::Exists(exe_path + DIR_SEP "portable.txt"))
+     {
+       user_path = exe_path + DIR_SEP "User" DIR_SEP;
+     }

forcexdg.patch

@@ -1,45 +0,0 @@
-diff --git a/Source/Core/UICommon/UICommon.cpp b/Source/Core/UICommon/UICommon.cpp
-index 2055c4d863..163a15f8a5 100644
---- a/Source/Core/UICommon/UICommon.cpp
-+++ b/Source/Core/UICommon/UICommon.cpp
-@@ -273,28 +273,11 @@ void SetUserDirectory(const std::string& custom_path)
-       user_path = home_path + DOLPHIN_DATA_DIR DIR_SEP;
-     }
- #else
--    // We are on a non-Apple and non-Android POSIX system, there are 4 cases:
--    // 1. GetExeDirectory()/portable.txt exists
--    //    -> Use GetExeDirectory()/User
--    // 2. $DOLPHIN_EMU_USERPATH is set
--    //    -> Use $DOLPHIN_EMU_USERPATH
--    // 3. ~/.dolphin-emu directory exists
--    //    -> Use ~/.dolphin-emu
-     // 4. Default
-     //    -> Use XDG basedir, see
-     //    http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
-     user_path = home_path + "." DOLPHIN_DATA_DIR DIR_SEP;
-     std::string exe_path = File::GetExeDirectory();
--    if (File::Exists(exe_path + DIR_SEP "portable.txt"))
--    {
--      user_path = exe_path + DIR_SEP "User" DIR_SEP;
--    }
--    else if (env_path)
--    {
--      user_path = env_path;
--    }
--    else if (!File::Exists(user_path))
--    {
-       const char* data_home = getenv("XDG_DATA_HOME");
-       std::string data_path =
-           std::string(data_home && data_home[0] == '/' ? data_home :
-@@ -316,11 +299,9 @@ void SetUserDirectory(const std::string& custom_path)
-       File::SetUserPath(D_CONFIG_IDX, config_path);
-       File::SetUserPath(D_CACHE_IDX, cache_path);
-       return;
--    }
- #endif
-   }
- #endif
--  File::SetUserPath(D_USER_IDX, std::move(user_path));
- }
-
- void SaveWiimoteSources()

org.DolphinEmu.dolphin-emu.yml

@@ -112,11 +112,13 @@ modules:
       - type: git
         url: https://github.com/dolphin-emu/dolphin.git
         commit: 8ecfa537a242de74d2e372e30d9d79b14584b2fb
+      # detects whether dolphin is running in a flatpak sandbox
+      # and makes it use xdg directories if it is.
       # prevents dolphin from attempting to write conf files
       # in non-writable paths, typically happens when a user
       # has leftover files from a previous non-flatpak install
       - type: patch
-        path: forcexdg.patch
+        path: detectflatpak.patch
       # version strings must match exactly for online multiplayer
       - type: patch
         path: nodirtyversion.patch