src: fix empty-named env var assertion failure

Setting an environment variable with an empty name on Windows resulted in an assertion failure, because it was checked for an '=' sign at the beginning without verifying the length was greater than 0. Fixes: nodejs#32920 Refs: nodejs#27310 PR-URL: nodejs#32921 Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: David Carlier <devnexen@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com> Reviewed-By: Zeyu Yang <himself65@outlook.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>

Author: bl-ue

src/node_env_var.cc

@@ -121,7 +121,7 @@ void RealEnvStore::Set(Isolate* isolate,
  node::Utf8Value val(isolate, value);
 
 #ifdef _WIN32
- if (key[0] == L'=') return;
+ if (key.length() > 0 && key[0] == L'=') return;
 #endif
  uv_os_setenv(*key, *val);
  DateTimeConfigurationChangeNotification(isolate, key);

test/parallel/test-process-env.js

@@ -106,3 +106,11 @@ if (common.isWindows) {
  const keys = Object.keys(process.env);
  assert.ok(keys.length > 0);
 }
+
+// Setting environment variables on Windows with empty names should not cause
+// an assertion failure.
+// https://github.com/nodejs/node/issues/32920
+{
+ process.env[''] = '';
+ assert.strictEqual(process.env[''], undefined);
+}