App: Fix safe mode and home directory

src/App/Application.cpp

@@ -2569,13 +2569,13 @@ void Application::initConfig(int argc, char ** argv)
         mConfig["KeepDeprecatedPaths"] = "1";
     }
 
+    if (vm.contains("safe-mode")) {
+        mConfig["SafeMode"] = "1";
+    }
+
     // extract home paths
     _appDirs = std::make_unique<ApplicationDirectories>(mConfig);
 
-    if (vm.contains("safe-mode")) {
-        SafeMode::StartSafeMode();
-    }
-
 #   ifdef FC_DEBUG
     mConfig["Debug"] = "1";
 #   else

src/App/ApplicationDirectories.cpp

@@ -37,6 +37,7 @@
 
 #include <Base/FileInfo.h>
 #include <Base/Exception.h>
+#include "SafeMode.h"
 
 #include <Python.h>
 #include <QString>
@@ -68,6 +69,11 @@ const fs::path& ApplicationDirectories::getHomePath() const
     return this->_home;
 }
 
+const fs::path& ApplicationDirectories::getUserHomePath() const
+{
+    return this->_userHome;
+}
+
 const fs::path& ApplicationDirectories::getTempPath() const {
     return this->_temp;
 }
@@ -182,10 +188,19 @@ void ApplicationDirectories::configurePaths(std::map<std::string,std::string>& m
     // get the system standard paths
     auto [configHome, dataHome, cacheHome, tempPath] = getStandardPaths();
 
+    if (mConfig.contains("SafeMode")) {
+        if (startSafeMode(mConfig)) {
+            // If we're in safe mode, don't try to set any directories here, they've been overridden
+            // by temp directories in the SafeMode setup.
+            return;
+        }
+    }
+
     // User home path
     //
     fs::path homePath = findUserHomePath(customHome);
     mConfig["UserHomePath"] = Base::FileInfo::pathToString(homePath);
+    _userHome = homePath;
 
     // the old path name to save config and data files
     std::vector<std::string> subdirs;
@@ -243,6 +258,23 @@ void ApplicationDirectories::configurePaths(std::map<std::string,std::string>& m
     mConfig["UserMacroPath"] = Base::FileInfo::pathToString(macro) + PATHSEP;
 }
 
+bool ApplicationDirectories::startSafeMode(std::map<std::string,std::string>& mConfig)
+{
+    SafeMode::StartSafeMode();
+    if (SafeMode::SafeModeEnabled()) {
+        _userAppData = mConfig["UserAppData"];
+        _userConfig = mConfig["UserConfigPath"];
+        _userCache = mConfig["UserCachePath"];
+        _temp = mConfig["AppTempPath"];
+        _userMacro = mConfig["UserMacroPath"];
+        _userHome = mConfig["UserHomePath"];
+        _usingCustomDirectories = true;
+        return true;
+    }
+    return false;
+}
+
+
 void ApplicationDirectories::configureResourceDirectory(const std::map<std::string,std::string>& mConfig) {
 #ifdef RESOURCEDIR
     // #6892: Conda may inject null characters => remove them using c_str()

src/App/ApplicationDirectories.h

@@ -56,6 +56,10 @@ namespace App {
         /// `App::ApplicationDirectories` class.
         const std::filesystem::path& getHomePath() const;
 
+        /// Get the user's home directory. This should not be used for many things, use caution when
+        /// deciding to use it for anything, there are usually better places.
+        const std::filesystem::path& getUserHomePath() const;
+
         /// Temp path is the location of all temporary files: it is not guaranteed to preserve
         /// information between runs of the program, but *is* guaranteed to exist for the duration
         /// of a single program execution (that is, files are not deleted from it *during* the run).
@@ -174,6 +178,10 @@ namespace App {
 
     protected:
 
+        /// Override all application directories with temp directories. Returns true on success and
+        /// false if the temp directory creation failed.
+        bool startSafeMode(std::map<std::string,std::string>& mConfig);
+
         /// Take a path and add a version to it, if it's possible to do so. A version can be
         /// appended only if a) the versioned subdirectory already exists, or b) pathToCheck/subdirs
         /// does NOT yet exist. This does not actually create any directories, just determines
@@ -228,6 +236,7 @@ namespace App {
         std::filesystem::path _userConfig;
         std::filesystem::path _userAppData;
         std::filesystem::path _userMacro;
+        std::filesystem::path _userHome;
         std::filesystem::path _resource;
         std::filesystem::path _library;
         std::filesystem::path _help;