child_process: check for closed pipes after creating socket

After the socket is created, we trigger an empty read to make sure we
catch stdio events like closing the stdin file descriptor. Otherwise
those events will go undetected until the next stream write.

Fixes: nodejs#25131

lib/internal/child_process.js

@@ -447,6 +447,10 @@ ChildProcess.prototype.spawn = function(options) {
       stream.socket = createSocket(this.pid !== 0 ?
         stream.handle : null, i > 0);
 
+      // Trigger an empty read to check for a closed pipe
+      // or the close event will go undetected until next write
+      stream.socket.read(0);
+
       if (i > 0 && this.pid !== 0) {
         this._closesNeeded++;
         stream.socket.on('close', () => {

test/parallel/test-child-process-spawn-close-stdin.js

@@ -0,0 +1,19 @@
+'use strict';
+// Refs: https://github.com/nodejs/node/issues/25131
+const common = require('../common');
+const cp = require('child_process');
+const fs = require('fs');
+
+if (process.argv[2] === 'child') {
+  fs.closeSync(0);
+} else {
+  const child = cp.spawn(process.execPath, [__filename, 'child'], {
+    stdio: ['pipe', 'inherit', 'inherit']
+  });
+
+  child.stdin.on('close', common.mustCall(() => {
+    process.exit(0);
+  }));
+
+  child.on('close', common.mustNotCall(() => {}));
+}