intl: Don't crash if v8BreakIterator not available

If the undocumented v8BreakIterator does not have data available,
monkeypatch it to throw an error instead of crashing.

Fixes: #3111
PR-URL: #4253
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

lib/internal/process.js

@@ -117,6 +117,21 @@ function setupConfig(_source) {
     if (value === 'false') return false;
     return value;
   });
+  const processConfig = process.binding('config');
+  // Intl.v8BreakIterator() would crash w/ fatal error, so throw instead.
+  if (processConfig.hasIntl &&
+      processConfig.hasSmallICU &&
+      Intl.hasOwnProperty('v8BreakIterator') &&
+      !process.icu_data_dir) {
+    const des = Object.getOwnPropertyDescriptor(Intl, 'v8BreakIterator');
+    des.value = function v8BreakIterator() {
+      throw new Error('v8BreakIterator: full ICU data not installed. ' +
+                      'See https://github.com/nodejs/node/wiki/Intl');
+    };
+    Object.defineProperty(Intl, 'v8BreakIterator', des);
+  }
+  // Don’t let icu_data_dir leak through.
+  delete process.icu_data_dir;
 }
 
 

src/node.cc

@@ -2976,6 +2976,13 @@ void SetupProcessObject(Environment* env,
   READONLY_PROPERTY(versions,
                     "icu",
                     OneByteString(env->isolate(), U_ICU_VERSION));
+
+  if (icu_data_dir != nullptr) {
+    // Did the user attempt (via env var or parameter) to set an ICU path?
+    READONLY_PROPERTY(process,
+                      "icu_data_dir",
+                      OneByteString(env->isolate(), icu_data_dir));
+  }
 #endif
 
   const char node_modules_version[] = NODE_STRINGIFY(NODE_MODULE_VERSION);

test/parallel/test-intl-v8BreakIterator.js

@@ -0,0 +1,15 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+if (global.Intl === undefined || Intl.v8BreakIterator === undefined) {
+  return console.log('1..0 # Skipped: no Intl');
+}
+
+try {
+  new Intl.v8BreakIterator();
+  // May succeed if data is available - OK
+} catch (e) {
+  // May throw this error if ICU data is not available - OK
+  assert.throws(() => new Intl.v8BreakIterator(), /ICU data/);
+}