fix: the winpath in winpath.cpp

nsis/winpath.cpp

@@ -15,24 +15,21 @@
 // This will start a Windows command line with PATH extended by
 // the location of the winpath executable.
 
+#include <filesystem>   // std::filesystem::path
 #include <process.h>    // _spawnvp
-#include <stdlib.h>     // _putenv_s
-#include <string.h>     // strcpy, strcat
-
-static char path[4096];
+#include <cstdlib>      // _putenv_s, getenv
+#include <string>       // std::string
 
 int main(int argc, char *argv[]) {
   if (argc > 1) {
-    char *dir = argv[0];
-    char *last = strrchr(dir, '\\');
-    if (last != nullptr) {
-      *last = '\0';
-    }
-    strcpy(path, dir);
-    strcat(path, ";");
-    strcat(path, getenv("PATH"));
-    _putenv_s("PATH", path);
-    _spawnvp(_P_WAIT, argv[1], argv + 1);
+    std::filesystem::path exe_path(argv[0]);
+    std::string dir = exe_path.parent_path().string();
+
+    const char *env_path = getenv("PATH");
+    std::string new_path = dir + ";" + (env_path ? env_path : "");
+
+    _putenv_s("PATH", new_path.c_str());
+    return _spawnvp(_P_WAIT, argv[1], argv + 1);
     //~ _spawnvp(_P_OVERLAY, argv[1], argv + 1);
   }
   return 0;