Set FD_CLOEXEC flag on stdio FDs before spawning.

With regression test.

1 files changed, 71 insertions, 0 deletions

diff --git a/test/simple/test-child-process-double-pipe.js b/test/simple/test-child-process-double-pipe.js
new file mode 100644
index 00000000000..f98cb65ff14
--- /dev/null
+++ b/test/simple/test-child-process-double-pipe.js
@@ -0,0 +1,71 @@
+var assert   = require('assert'),
+    util   = require('util'),
+    spawn = require('child_process').spawn;
+
+// We're trying to reproduce:
+// $ echo -e "hello\nnode\nand\nworld" | grep o | sed s/o/a/
+
+var
+  echo    = spawn('echo', ['-e', 'hello\nnode\nand\nworld\n']),
+  grep  = spawn('grep', ['o']),
+  sed  = spawn('sed', ['s/o/O/']);
+
+/*
+ * grep and sed hang if the spawn function leaks file descriptors to child
+ * processes.
+ * This happens when calling pipe(2) and then forgetting to set the
+ * FD_CLOEXEC flag on the resulting file descriptors.
+ *
+ * This test checks child processes exit, meaning they don't hang like
+ * explained above.
+ */
+
+
+
+// pipe echo | grep
+echo.stdout.on('data', function (data) {
+  if (!grep.stdin.write(data)) {
+    echo.stdout.pause();
+  }
+});
+
+grep.stdin.on('drain', function (data) {
+  echo.stdout.resume();
+});
+
+// propagate end from echo to grep
+echo.stdout.on('end', function (code) {
+  grep.stdin.end();
+});
+
+
+
+// pipe grep | sed
+grep.stdout.on('data', function (data) {
+  if (!sed.stdin.write(data)) {
+    grep.stdout.pause();
+  }
+});
+
+sed.stdin.on('drain', function (data) {
+  grep.stdout.resume();
+});
+
+// propagate end from grep to sed
+grep.stdout.on('end', function (code) {
+  sed.stdin.end();
+});
+
+
+
+var result = '';
+
+// print sed's output
+sed.stdout.on('data', function (data) {
+  result += data.toString('utf8', 0, data.length);
+  util.print(data);
+});
+
+sed.stdout.on('end', function (code) {
+  assert.equal(result, 'hellO\nnOde\nwOrld\n');
+});