[C++] Add chdir back if --ninja_dir is not specified
diff --git a/ninja.cc b/ninja.cc
index 05c8455..2aa118a 100644
--- a/ninja.cc
+++ b/ninja.cc
@@ -559,6 +559,8 @@
     fprintf(fp, "#!%s\n", shell->c_str());
     fprintf(fp, "# Generated by kati %s\n", kGitVersion);
     fprintf(fp, "\n");
+    if (ninja_dir_ == ".")
+      fprintf(fp, "cd $(dirname \"$0\")\n");
 
     for (const auto& p : ev_->exports()) {
       if (p.second) {