process: correctly parse Unicode in NODE_OPTIONS

src/node_credentials.cc

@@ -57,8 +57,20 @@ bool SafeGetenv(const char* key, std::string* text, Environment* env) {
 
   {
     Mutex::ScopedLock lock(per_process::env_var_mutex);
-    if (const char* value = getenv(key)) {
-      *text = value;
+
+    size_t init_sz = 256;
+    MaybeStackBuffer<char, 256> val;
+    int ret = uv_os_getenv(key, *val, &init_sz);
+
+    if (ret == UV_ENOBUFS) {
+      // Buffer is not large enough, reallocate to the updated init_sz
+      // and fetch env value again.
+      val.AllocateSufficientStorage(init_sz);
+      ret = uv_os_getenv(key, *val, &init_sz);
+    }
+
+    if (ret >= 0) {  // Env key value fetch success.
+      *text = *val;
       return true;
     }
   }

test/parallel/test-unicode-node-options.js

@@ -0,0 +1,26 @@
+'use strict';
+// Flags: --expose-internals
+require('../common');
+const { getOptionValue } = require('internal/options');
+const assert = require('assert');
+const cp = require('child_process');
+
+const expected_redirect_value = 'foó';
+
+if (process.argv.length === 2) {
+  const NODE_OPTIONS = `--redirect-warnings=${expected_redirect_value}`;
+  const result = cp.spawnSync(process.argv0,
+                              ['--expose-internals', __filename, 'test'],
+                              {
+                                env: {
+                                  ...process.env,
+                                  NODE_OPTIONS
+                                },
+                                stdio: 'inherit'
+                              });
+  assert.strictEqual(result.status, 0);
+} else {
+  const redirect_value = getOptionValue('--redirect-warnings');
+  console.log(`--redirect-warings=${redirect_value}`);
+  assert.strictEqual(redirect_value, expected_redirect_value);
+}