From 5ba807a3f4bee77b6bf4dd889d2fc99d1195c3b7 Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Fri, 20 May 2016 23:11:27 +0200
Subject: [PATCH] module: don't cache uninitialized builtins

Don't cache the exported values of fully uninitialized builtins.
This works by adding an additional `loading` flag that is only
active during initial loading of an internal module and checking
that either the module is fully loaded or is in that state before
using its cached value.

This has the effect that builtins modules which could not be loaded
(e.g. because compilation failed due to missing stack space) can be
loaded at a later point.

Fixes: https://github.com/nodejs/node/issues/6899

Ref: https://github.com/nodejs/node/issues/6899
PR-URL: https://github.com/nodejs/node/pull/6907
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
---
 src/node.js                              | 20 +++++++++++++-------
 test/message/console_low_stack_space.js  | 22 ++++++++++++++++++++++
 test/message/console_low_stack_space.out |  1 +
 3 files changed, 36 insertions(+), 7 deletions(-)
 create mode 100644 test/message/console_low_stack_space.js
 create mode 100644 test/message/console_low_stack_space.out

diff --git a/src/node.js b/src/node.js
index 7301d9d114ed98..a4d86da6a93a69 100644
--- a/src/node.js
+++ b/src/node.js
@@ -877,6 +877,7 @@
     this.id = id;
     this.exports = {};
     this.loaded = false;
+    this.loading = true;
   }
 
   NativeModule._source = process.binding('natives');
@@ -888,7 +889,7 @@
     }
 
     var cached = NativeModule.getCached(id);
-    if (cached) {
+    if (cached && (cached.loaded || cached.loading)) {
       return cached.exports;
     }
 
@@ -952,13 +953,18 @@
     var source = NativeModule.getSource(this.id);
     source = NativeModule.wrap(source);
 
-    var fn = runInThisContext(source, {
-      filename: this.filename,
-      lineOffset: 0
-    });
-    fn(this.exports, NativeModule.require, this, this.filename);
+    this.loading = true;
+    try {
+      var fn = runInThisContext(source, {
+        filename: this.filename,
+        lineOffset: 0
+      });
+      fn(this.exports, NativeModule.require, this, this.filename);
 
-    this.loaded = true;
+      this.loaded = true;
+    } finally {
+      this.loading = false;
+    }
   };
 
   NativeModule.prototype.cache = function() {
diff --git a/test/message/console_low_stack_space.js b/test/message/console_low_stack_space.js
new file mode 100644
index 00000000000000..1685a35a1f9304
--- /dev/null
+++ b/test/message/console_low_stack_space.js
@@ -0,0 +1,22 @@
+'use strict';
+// copy console accessor because requiring ../common touches it
+const consoleDescriptor = Object.getOwnPropertyDescriptor(global, 'console');
+delete global.console;
+global.console = {};
+
+require('../common');
+
+function a() {
+  try {
+    return a();
+  } catch (e) {
+    const console = consoleDescriptor.get();
+    if (console.log) {
+      console.log('Hello, World!');
+    } else {
+      throw e;
+    }
+  }
+}
+
+a();
diff --git a/test/message/console_low_stack_space.out b/test/message/console_low_stack_space.out
new file mode 100644
index 00000000000000..8ab686eafeb1f4
--- /dev/null
+++ b/test/message/console_low_stack_space.out
@@ -0,0 +1 @@
+Hello, World!