python: fix segfault on empty argv in main() (#2003)

Co-authored-by: dominic <510002+dmah42@users.noreply.github.com>

Author: senyai

bindings/python/google_benchmark/benchmark.cc

@@ -14,16 +14,18 @@ namespace {
 namespace nb = nanobind;
 
 std::vector<std::string> Initialize(const std::vector<std::string>& argv) {
-  // The `argv` pointers here become invalid when this function returns, but
-  // benchmark holds the pointer to `argv[0]`. We create a static copy of it
-  // so it persists, and replace the pointer below.
-  static std::string executable_name(argv[0]);
   std::vector<char*> ptrs;
   ptrs.reserve(argv.size());
   for (auto& arg : argv) {
     ptrs.push_back(const_cast<char*>(arg.c_str()));
   }
-  ptrs[0] = const_cast<char*>(executable_name.c_str());
+  if (!ptrs.empty()) {
+    // The `argv` pointers here become invalid when this function returns, but
+    // benchmark holds the pointer to `argv[0]`. We create a static copy of it
+    // so it persists, and replace the pointer below.
+    static std::string executable_name(argv[0]);
+    ptrs[0] = const_cast<char*>(executable_name.c_str());
+  }
   int argc = static_cast<int>(argv.size());
   benchmark::Initialize(&argc, ptrs.data());
   std::vector<std::string> remaining_argv;