fix: Filesystem::unique_path wasn't using the unicode rectified string (

#4203)

Signed-off-by: Larry Gritz <[email protected]>

src/libutil/filesystem.cpp

@@ -507,24 +507,30 @@ Filesystem::unique_path(string_view model)
     // See boost/filesystem/path.hpp
     // The only correct way to do this is to do the conversion ourselves
     std::wstring modelStr = Strutil::utf8_to_utf16wstring(model);
+    std::wstring name;
 #    else
     std::string modelStr = model.str();
+    std::string name;
 #    endif
     static const char chrs[] = "0123456789abcdef";
     static std::mt19937 rg { std::random_device {}() };
     static std::uniform_int_distribution<size_t> pick(0, 15);
     static std::mutex mutex;
     std::lock_guard<std::mutex> lock(mutex);
-    std::string name;
     while (true) {
-        name = model.str();
-        for (size_t i = 0, e = model.size(); i < e; ++i)
+        name = modelStr;
+        // Replace the '%' characters in the name with random hex digits
+        for (size_t i = 0, e = modelStr.size(); i < e; ++i)
             if (name[i] == '%')
                 name[i] = chrs[pick(rg)];
         if (!exists(name))
             break;
     }
+#    if defined(_WIN32)
+    return Strutil::utf16_to_utf8(name);
+#    else
     return name;
+#    endif
 #endif
 }