From 7157c29ea5249b2217048bb4acfcd3d1492efc24 Mon Sep 17 00:00:00 2001
From: Philipp Stephani <phst@google.com>
Date: Thu, 23 Dec 2021 23:29:21 +0100
Subject: [PATCH] Allow argc = 0.
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This is allowed according to the C++ standard, so don’t invoke undefined
behavior when converting argv[0] to a string.
---
 elisp/binary.template | 6 ++++--
 emacs/driver.template | 6 ++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/elisp/binary.template b/elisp/binary.template
index 80078fd3..48ef800c 100644
--- a/elisp/binary.template
+++ b/elisp/binary.template
@@ -17,12 +17,14 @@
 #include "elisp/binary.h"
 
 int PHST_RULES_ELISP_MAIN(int argc, phst_rules_elisp::NativeChar** argv) {
-  std::vector<phst_rules_elisp::NativeString> args = {
+  using phst_rules_elisp::NativeString;
+  using phst_rules_elisp::RunBinary;
+  std::vector<NativeString> args = {
     [[args]],
     PHST_RULES_ELISP_NATIVE_LITERAL("--")
   };
   args.insert(args.end(), argv, argv + argc);
-  return phst_rules_elisp::RunBinary(argv[0], args);
+  return RunBinary(argc == 0 ? NativeString() : argv[0], args);
 }
 
 // Local Variables:
diff --git a/emacs/driver.template b/emacs/driver.template
index c91c26c3..c95ac0ac 100644
--- a/emacs/driver.template
+++ b/emacs/driver.template
@@ -17,12 +17,14 @@
 #include "elisp/emacs.h"
 
 int PHST_RULES_ELISP_MAIN(int argc, phst_rules_elisp::NativeChar** argv) {
-  std::vector<phst_rules_elisp::NativeString> args = {
+  using phst_rules_elisp::NativeString;
+  using phst_rules_elisp::RunEmacs;
+  std::vector<NativeString> args = {
     [[args]],
     PHST_RULES_ELISP_NATIVE_LITERAL("--")
   };
   args.insert(args.end(), argv, argv + argc);
-  return phst_rules_elisp::RunEmacs(argv[0], args);
+  return RunEmacs(argc == 0 ? NativeString() : argv[0], args);
 }
 
 // Local Variables: