Use standard paths for storing LOOT data on Linux.

Fixes #494.

src/backend/globals.cpp.in

@@ -38,11 +38,7 @@ namespace loot {
     const boost::filesystem::path g_path_readme         = boost::filesystem::current_path() / "docs" / "LOOT Readme.html";
     const boost::filesystem::path g_path_report         = boost::filesystem::current_path() / "resources" / "ui" / "index.html";
     const boost::filesystem::path g_path_l10n           = boost::filesystem::current_path() / "resources" / "l10n";
-#ifdef _WIN32
     const boost::filesystem::path g_path_local          = GetLocalAppDataPath() / "LOOT";
-#else
-    const boost::filesystem::path g_path_local          = boost::filesystem::current_path() / "LOOT";
-#endif
     const boost::filesystem::path g_path_settings       = g_path_local / "settings.yaml";
     const boost::filesystem::path g_path_log            = g_path_local / "LOOTDebugLog.txt";
 }

src/backend/helpers/helpers.cpp

@@ -130,6 +130,36 @@ namespace loot {
 #endif
     }
 
+    boost::filesystem::path GetLocalAppDataPath() {
+#ifdef _WIN32
+        HWND owner = 0;
+        PWSTR path;
+
+        if (SHGetKnownFolderPath(FOLDERID_LocalAppData, 0, NULL, &path) != S_OK)
+            throw error(error::windows_error, lc::translate("Failed to get %LOCALAPPDATA% path."));
+
+        fs::path localAppDataPath(FromWinWide(path));
+        CoTaskMemFree(path);
+
+        return localAppDataPath;
+#else
+        // Use XDG_CONFIG_HOME environmental variable if it's available.
+        const char * xdgConfigHome = getenv("XDG_CONFIG_HOME");
+
+        if (xdgConfigHome != nullptr)
+            return fs::path(xdgConfigHome);
+
+        // Otherwise, use the HOME env. var. if it's available.
+        xdgConfigHome = getenv("HOME");
+
+        if (xdgConfigHome != nullptr)
+            return fs::path(xdgConfigHome) / ".config";
+
+        // If somehow both are missing, use the current path.
+        return fs::current_path();
+#endif
+    }
+
 #ifdef _WIN32
     //Get registry subkey value string.
     string RegKeyStringValue(const std::string& keyStr, const std::string& subkey, const std::string& value) {
@@ -169,18 +199,6 @@ namespace loot {
         }
     }
 
-    boost::filesystem::path GetLocalAppDataPath() {
-        HWND owner = 0;
-        TCHAR path[MAX_PATH];
-
-        HRESULT res = SHGetFolderPath(owner, CSIDL_LOCAL_APPDATA, NULL, SHGFP_TYPE_CURRENT, path);
-
-        if (res == S_OK)
-            return fs::path(path);
-        else
-            return fs::path("");
-    }
-
     //Helper to turn UTF8 strings into strings that can be used by WinAPI.
     std::wstring ToWinWide(const std::string& str) {
         size_t len = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), str.length(), 0, 0);

src/backend/helpers/helpers.h

@@ -42,13 +42,13 @@ namespace loot {
     //Opens the file in its registered default application.
     void OpenInDefaultApplication(const boost::filesystem::path& file);
 
+    //Get the local application data path, within which LOOT's data folder should be stored.
+    boost::filesystem::path GetLocalAppDataPath();
+
 #ifdef _WIN32
     //Get registry subkey value string.
     std::string RegKeyStringValue(const std::string& keyStr, const std::string& subkey, const std::string& value);
 
-    //Get the local application data path, within which LOOT's data folder should be stored.
-    boost::filesystem::path GetLocalAppDataPath();
-
     //Helper to turn UTF8 strings into strings that can be used by WinAPI.
     std::wstring ToWinWide(const std::string& str);