[v10.x] src: allows escaping NODE_OPTIONS with backslashes

doc/api/cli.md

@@ -642,6 +642,13 @@ if they had been specified on the command line before the actual command line
 (so they can be overridden). Node.js will exit with an error if an option
 that is not allowed in the environment is used, such as `-p` or a script file.
 
+In case an option value happens to contain a space (for example a path listed in
+`--require`), it must be escaped using double quotes. For example:
+
+```bash
+--require "./my path/file.js"
+```
+
 Node.js options that are allowed are:
 - `--enable-fips`
 - `--experimental-modules`

src/node.cc

@@ -2610,23 +2610,49 @@ void Init(std::vector<std::string>* argv,
 
 #if !defined(NODE_WITHOUT_NODE_OPTIONS)
   std::string node_options;
+
   if (SafeGetenv("NODE_OPTIONS", &node_options)) {
     std::vector<std::string> env_argv;
     // [0] is expected to be the program name, fill it in from the real argv.
     env_argv.push_back(argv->at(0));
 
-    // Split NODE_OPTIONS at each ' ' character.
-    std::string::size_type index = std::string::npos;
-    do {
-      std::string::size_type prev_index = index;
-      index = node_options.find(' ', index + 1);
-      if (index - prev_index == 1) continue;
-
-      const std::string option = node_options.substr(
-          prev_index + 1, index - prev_index - 1);
-      if (!option.empty())
-        env_argv.emplace_back(std::move(option));
-    } while (index != std::string::npos);
+    bool is_in_string = false;
+    bool will_start_new_arg = true;
+    for (std::string::size_type index = 0;
+         index < node_options.size();
+         ++index) {
+      char c = node_options.at(index);
+
+      // Backslashes escape the following character
+      if (c == '\\' && is_in_string) {
+        if (index + 1 == node_options.size()) {
+          fprintf(stderr, "invalid value for NODE_OPTIONS "
+                          "(invalid escape)\n");
+          exit(9);
+        } else {
+          c = node_options.at(++index);
+        }
+      } else if (c == ' ' && !is_in_string) {
+        will_start_new_arg = true;
+        continue;
+      } else if (c == '"') {
+        is_in_string = !is_in_string;
+        continue;
+      }
+
+      if (will_start_new_arg) {
+        env_argv.push_back(std::string(1, c));
+        will_start_new_arg = false;
+      } else {
+        env_argv.back() += c;
+      }
+    }
+
+    if (is_in_string) {
+      fprintf(stderr, "invalid value for NODE_OPTIONS "
+                      "(unterminated string)\n");
+      exit(9);
+    }
 
 
     ProcessArgv(&env_argv, nullptr, true);

test/fixtures/print A.js

@@ -0,0 +1 @@
+console.log('A')

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

@@ -15,7 +15,12 @@ tmpdir.refresh();
 process.chdir(tmpdir.path);
 
 const printA = require.resolve('../fixtures/printA.js');
+const printSpaceA = require.resolve('../fixtures/print A.js');
+
+expect(` -r ${printA} `, 'A\nB\n');
 expect(`-r ${printA}`, 'A\nB\n');
+expect(`-r ${JSON.stringify(printA)}`, 'A\nB\n');
+expect(`-r ${JSON.stringify(printSpaceA)}`, 'A\nB\n');
 expect(`-r ${printA} -r ${printA}`, 'A\nB\n');
 expect('--no-deprecation', 'B\n');
 expect('--no-warnings', 'B\n');