[asan] Fix argv array for PyROOT applications (#22768)

* [asan] Fix argv array for PyROOT applications

pick these changes from #22746:
- The argv array for PyROOT applications was one element too small
This fixes 20 failing pyunittests on Windows. Thanks @hageboeck!

* clang-format

Author: bellenot

bindings/pyroot/pythonizations/src/RPyROOTApplication.cxx

@@ -46,7 +46,8 @@ bool PyROOT::RPyROOTApplication::CreateApplication(int ignoreCmdLineOpts)
       char **argv = nullptr;
 
       if (ignoreCmdLineOpts) {
-         argv = new char *[argc];
+         // Last argv must be null (see https://en.cppreference.com/cpp/language/main_function)
+         argv = new char *[argc + 1] {};
       } else {
          // Retrieve sys.argv list from Python
          PyObject *argl = PySys_GetObject("argv");
@@ -57,7 +58,8 @@ bool PyROOT::RPyROOTApplication::CreateApplication(int ignoreCmdLineOpts)
                argc = static_cast<int>(size);
          }
 
-         argv = new char *[argc];
+         // Last argv must be null (see https://en.cppreference.com/cpp/language/main_function)
+         argv = new char *[argc + 1] {};
 
          for (int i = 1; i < argc; ++i) {
             PyObject *item = PyList_GetItem(argl, i);