From 11ae6ba6f528db3c611825254ccac56329277adc Mon Sep 17 00:00:00 2001
From: Leon Styhre <leon@leonstyhre.com>
Date: Wed, 30 Jun 2021 17:27:20 +0200
Subject: [PATCH] Improved the support for portable installations.

---
 es-app/src/main.cpp                         | 46 +++++++++++++++++++++
 resources/systems/windows/es_find_rules.xml |  3 ++
 2 files changed, 49 insertions(+)

diff --git a/es-app/src/main.cpp b/es-app/src/main.cpp
index dd5ef6a8b..aa61a3c62 100644
--- a/es-app/src/main.cpp
+++ b/es-app/src/main.cpp
@@ -48,6 +48,7 @@
 #endif
 
 #include <FreeImage.h>
+#include <fstream>
 #include <iostream>
 #include <time.h>
 
@@ -136,6 +137,46 @@ bool parseArgs(int argc, char* argv[])
         win64ConsoleType consoleType = outputToConsole(false);
     #endif
 
+    std::string portableFilePath = Utils::FileSystem::getExePath() + "/portable.txt";
+
+    // This is primarily intended for portable ES-DE installations on Windows (for example
+    // placed on a USB memory stick) but it may be usable for other operating systems too.
+    if (Utils::FileSystem::exists(portableFilePath)) {
+        std::cout << "Found portable.txt in the ES-DE executable directory\n";
+        std::ifstream portableFile;
+        std::string homePath;
+        #if defined(_WIN64)
+        portableFile.open(Utils::String::stringToWideString(portableFilePath).c_str());
+        #else
+        portableFile.open(portableFilePath.c_str());
+        #endif
+        if (!portableFile.fail()) {
+            std::string relativePath;
+            getline(portableFile, relativePath);
+            // If the file is empty, use the ES-DE executable directory as home.
+            if (relativePath == "")
+                homePath = Utils::FileSystem::getExePath();
+            else
+                homePath = Utils::FileSystem::getExePath() + "/" + relativePath;
+
+            #if defined(_WIN64)
+            homePath = Utils::String::replace(homePath, "/", "\\");
+            #endif
+
+            if (!Utils::FileSystem::exists(homePath)) {
+                std::cerr << "Error: Defined home path \"" << homePath << "\" does not exist\n";
+            }
+            else if (Utils::FileSystem::isRegularFile(homePath)) {
+                std::cerr << "Error: Defined home path \"" << homePath << "\" is a file\n";
+            }
+            else {
+                std::cout << "Setting home path to \"" << homePath << "\"\n";
+                Utils::FileSystem::setHomePath(homePath);
+            }
+        }
+        portableFile.close();
+    }
+
     // We need to process --home before any call to Settings::getInstance(),
     // because settings are loaded from the home path.
     for (int i = 1; i < argc; i++) {
@@ -359,8 +400,13 @@ bool checkApplicationHomeDirectory()
     std::string home = Utils::FileSystem::getHomePath();
     std::string applicationHome = home + "/.emulationstation";
     if (!Utils::FileSystem::exists(applicationHome)) {
+        #if defined(_WIN64)
+            std::cout << "First startup, creating application home directory \"" <<
+                Utils::String::replace(applicationHome, "/", "\\") << "\"\n";
+        #else
         std::cout << "First startup, creating application home directory \"" <<
                 applicationHome << "\"\n";
+        #endif
         Utils::FileSystem::createDirectory(applicationHome);
         if (!Utils::FileSystem::exists(applicationHome)) {
             std::cerr << "Fatal error: Couldn't create directory, permission problems?\n";
diff --git a/resources/systems/windows/es_find_rules.xml b/resources/systems/windows/es_find_rules.xml
index f0a9e0150..dc90587c1 100644
--- a/resources/systems/windows/es_find_rules.xml
+++ b/resources/systems/windows/es_find_rules.xml
@@ -20,6 +20,8 @@
       <entry>C:\Program Files (x86)\RetroArch-Win64\retroarch.exe</entry>
       <entry>C:\Program Files (x86)\RetroArch\retroarch.exe</entry>
       <!-- Portable installation -->
+      <entry>%ESPATH%\RetroArch-Win64\retroarch.exe</entry>
+      <entry>%ESPATH%\RetroArch\retroarch.exe</entry>
       <entry>%ESPATH%\..\RetroArch-Win64\retroarch.exe</entry>
       <entry>%ESPATH%\..\RetroArch\retroarch.exe</entry>
     </rule>
@@ -32,6 +34,7 @@
     <rule type="staticpath">
       <entry>~\AppData\Local\yuzu\yuzu-windows-msvc\yuzu.exe</entry>
       <!-- Portable installation -->
+      <entry>%ESPATH%\yuzu\yuzu-windows-msvc\yuzu.exe</entry>
       <entry>%ESPATH%\..\yuzu\yuzu-windows-msvc\yuzu.exe</entry>
     </rule>
   </emulator>