Windows: Modernize getSpecialFolderLocation

Ported from CSIDL to newer FOLDERID API and used wcstombs_s to
convert the returned path to a multi-byte string.

Fixes issues when the Windows username contains special characters.

3 files changed, 32 insertions, 33 deletions

diff --git a/src/client.cpp b/src/client.cpp
index 63452112..abd426ce 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -1116,7 +1116,7 @@ void Client::initHomeDir()
         mLocalDataDir = PHYSFS_getUserDir();
         mLocalDataDir += "/config/data/Mana";
 #elif defined _WIN32
-        mLocalDataDir = getSpecialFolderLocation(CSIDL_LOCAL_APPDATA);
+        mLocalDataDir = getSpecialFolderLocation(FOLDERID_LocalAppData);
         if (mLocalDataDir.empty())
             mLocalDataDir = PHYSFS_getUserDir();
         mLocalDataDir += "/Mana";
@@ -1281,9 +1281,9 @@ void Client::initScreenshotDir()
     else if (mScreenshotDir.empty())
     {
 #ifdef _WIN32
-        mScreenshotDir = getSpecialFolderLocation(CSIDL_MYPICTURES);
+        mScreenshotDir = getSpecialFolderLocation(FOLDERID_Pictures);
         if (mScreenshotDir.empty())
-            mScreenshotDir = getSpecialFolderLocation(CSIDL_DESKTOP);
+            mScreenshotDir = getSpecialFolderLocation(FOLDERID_Desktop);
 #else
         mScreenshotDir = std::string(PHYSFS_getUserDir()) + "Desktop";
 #endif
diff --git a/src/utils/specialfolder.cpp b/src/utils/specialfolder.cpp
index bd3e1bca..c351ba1a 100644
--- a/src/utils/specialfolder.cpp
+++ b/src/utils/specialfolder.cpp
@@ -1,6 +1,6 @@
 /*
  *  The Mana Client
- *  Copyright (C) 2010-2012  The Mana Developers
+ *  Copyright (C) 2010-2024  The Mana Developers
  *
  *  This file is part of The Mana Client.
  *
@@ -21,6 +21,7 @@
 #ifdef _WIN32
 #include "specialfolder.h"
 #include <windows.h>
+#include <stdlib.h>
 
 #ifdef SPECIALFOLDERLOCATION_TEST
 // compile with -DSPECIALFOLDERLOCATION_TEST to get a standalone
@@ -29,49 +30,47 @@
 #endif
 
 /*
- * Retrieve the pathname of special folders on win32, or an empty string
- * on error / if the folder does not exist.
- * See http://msdn.microsoft.com/en-us/library/bb762494(VS.85).aspx for
- * a list of folder ids
+ * Retrieve the pathname of special folders on Windows, or an empty string
+ * on error.
+ *
+ * See https://learn.microsoft.com/en-us/windows/win32/shell/knownfolderid
+ * for a list of folder IDs.
  */
-std::string getSpecialFolderLocation(int folderId)
+std::string getSpecialFolderLocation(const KNOWNFOLDERID &folderId)
 {
     std::string ret;
-    LPITEMIDLIST pItemIdList;
-    LPMALLOC pMalloc;
-    char szPath[MAX_PATH];
-
-    // get the item ID list for folderId
-    HRESULT hr = SHGetSpecialFolderLocation(NULL, folderId, &pItemIdList);
-    if (hr != S_OK)
-        return ret;
+    PWSTR widePath = 0;
 
-    // convert the ID list into a file system path
-    if (SHGetPathFromIDList(pItemIdList, szPath) == FALSE)
-        return ret;
+    HRESULT hr = SHGetKnownFolderPath(folderId, 0, NULL, &widePath);
+    if (hr == S_OK)
+    {
+        // determine needed bytes
+        size_t len;
+        if (wcstombs_s(&len, nullptr, 0, widePath, 0) == 0)
+        {
+            ret.resize(len - 1);    // subtract null character
+            if (wcstombs_s(nullptr, ret.data(), len, widePath, len - 1) != 0)
+                ret.clear();
+        }
+    }
 
-    // get the IMalloc pointer and free all resources we used
-    hr = SHGetMalloc(&pMalloc);
-    pMalloc->Free(pItemIdList);
-    pMalloc->Release();
+    CoTaskMemFree(widePath);
 
-    ret = szPath;
     return ret;
 }
 
 #ifdef SPECIALFOLDERLOCATION_TEST
 int main()
 {
-    std::cout << "APPDATA " << getSpecialFolderLocation(CSIDL_APPDATA)
+    std::cout << "RoamingAppData " << getSpecialFolderLocation(FOLDERID_RoamingAppData)
               << std::endl;
-    std::cout << "DESKTOP " << getSpecialFolderLocation(CSIDL_DESKTOP)
+    std::cout << "Desktop " << getSpecialFolderLocation(FOLDERID_Desktop)
               << std::endl;
-    std::cout << "LOCAL_APPDATA "
-              << getSpecialFolderLocation(CSIDL_LOCAL_APPDATA)
+    std::cout << "LocalAppData " << getSpecialFolderLocation(FOLDERID_LocalAppData)
               << std::endl;
-    std::cout << "MYPICTURES " << getSpecialFolderLocation(CSIDL_MYPICTURES)
+    std::cout << "Pictures " << getSpecialFolderLocation(FOLDERID_Pictures)
               << std::endl;
-    std::cout << "PERSONAL " << getSpecialFolderLocation(CSIDL_PERSONAL)
+    std::cout << "Documents " << getSpecialFolderLocation(FOLDERID_Documents)
               << std::endl;
 }
 #endif
diff --git a/src/utils/specialfolder.h b/src/utils/specialfolder.h
index 411752a2..8570d009 100644
--- a/src/utils/specialfolder.h
+++ b/src/utils/specialfolder.h
@@ -1,6 +1,6 @@
 /*
  *  The Mana Client
- *  Copyright (C) 2010-2012  The Mana Developers
+ *  Copyright (C) 2010-2024  The Mana Developers
  *
  *  This file is part of The Mana Client.
  *
@@ -24,7 +24,7 @@
 #ifdef _WIN32
 #include <shlobj.h>
 #include <string>
-std::string getSpecialFolderLocation(int folderId);
+std::string getSpecialFolderLocation(const KNOWNFOLDERID &folderId);
 #endif
 
 #endif