Boot - further unification of home path resolution

Both the API and the Ruby server do home directory detection and relative path resolution. Ideally this should be in one place, but in lieu of that, it is essential they both behave similarly.

Resolution now matches QDir::homePath():
The path specified by the SONIC_PI_HOME environment variable.
The path specified by the USERPROFILE environment variable. (windows only)
The path formed by concatenating the HOMEDRIVE and HOMEPATH environment variables. (windows only)
The path specified by the HOME environment variable.

Author: samaaron

app/api/src/sonicpi_api.cpp

@@ -83,26 +83,31 @@ fs::path SonicPiAPI::FindHomePath() const
     auto pszHome = std::getenv("SONIC_PI_HOME");
     if (pszHome != nullptr)
     {
-        homePath = fs::path(pszHome);
+        return pszHome;
     }
 
-    // Check for home path existence and if not, use user documents path
-    if (!fs::exists(homePath))
+#if defined(WIN32)
+    auto usrprofHome = std::getenv("USERPROFILE");
+    if (usrprofHome != nullptr)
     {
-        homePath = fs::path(sago::getDocumentsFolder()).parent_path();
+        return fs::path(usrprofHome);
     }
 
-    // Final attempt at getting the folder; try to create it if possible
-    if (!fs::exists(homePath))
+    auto homeDrive = std::getenv("HOMEDRIVE");
+    auto homePath = std::getenv("HOMEPATH");
+    if ((homeDrive  != nullptr) && (homePath != nullptr))
     {
-        std::error_code err;
-        if (!fs::create_directories(homePath, err))
-        {
-            // Didn't exist, and failed to create it
-            return fs::path();
-        }
+        return fs::path(homeDrive) / homePath;
     }
-    return homePath;
+#endif
+
+    auto home = std::getenv("HOME");
+    if (home != nullptr)
+    {
+        return fs::path(home);
+    }
+
+    return fs::path(sago::getDocumentsFolder()).parent_path();
 }
 
 std::error_code SonicPiAPI::RunProcess(const std::vector<std::string>& args, std::string* pOutput)

app/server/ruby/paths.rb

@@ -16,29 +16,30 @@
 module SonicPi
   module Paths
     def self.user_dir
+      return File.expand_path(ENV["SONIC_PI_HOME"]) if ENV["SONIC_PI_HOME"]
 
       # Figure out the user's home directory
       case os
       when :windows
+        return File.expand_path(ENV["USERPROFILE"]) if ENV["USERPROFILE"]
         # On Windows, Ruby lets HOME take precedence if it exists, which
         # is not what Sonic Pi should do to behave like a native Windows
         # app.  To get the same path as QDir::homePath() used by the
         # GUI, we must use HOMEDRIVE and HOMEPATH instead, if they are
         # set.
         home_drive = ENV["HOMEDRIVE"]
         home_path = ENV["HOMEPATH"]
-        if home_drive and home_path
-          File.expand_path(home_drive + home_path)
-        else
-          File.expand_path(Dir.home)
-        end
+        return File.absolute_path("#{home_drive}/#{home_path}") if home_drive and home_path
+        return File.expand_path(ENV["HOME"]) if ENV["HOME"]
+        return File.expand_path(Dir.home)
       else
-        File.expand_path(Dir.home)
+        return File.expand_path(ENV["HOME"]) if ENV["HOME"]
+        return File.expand_path(Dir.home)
       end
     end
 
     def self.home_dir_path
-      File.expand_path((ENV['SONIC_PI_HOME'] || user_dir) + '/.sonic-pi/')
+      File.absolute_path("#{user_dir}/.sonic-pi/")
     end
 
     def self.project_path