stream: lazy read ReadStream

Using stream._construct would cause the Readable
to incorrectly greedily start reading.

Fixes: https://github.com/nodejs/node/issues/36251

PR-URL: https://github.com/nodejs/node/pull/36823
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
This commit is contained in:
Momtchil Momtchev 2020-11-26 12:59:00 +01:00 committed by Robert Nagy
parent 7397c7e4a3
commit 053abac02b
3 changed files with 55 additions and 1 deletions

View file

@ -203,7 +203,9 @@ function Readable(options) {
Stream.call(this, options);
destroyImpl.construct(this, () => {
maybeReadMore(this, this._readableState);
if (this._readableState.needReadable) {
maybeReadMore(this, this._readableState);
}
});
}

View file

@ -0,0 +1,42 @@
'use strict';
const common = require('../common');
const process = require('process');
let defaultShell;
if (process.platform === 'linux' || process.platform === 'darwin') {
defaultShell = '/bin/sh';
} else if (process.platform === 'win32') {
defaultShell = 'cmd.exe';
} else {
common.skip('This is test exists only on Linux/Win32/OSX');
}
const { execSync } = require('child_process');
const fs = require('fs');
const path = require('path');
const tmpdir = require('../common/tmpdir');
const tmpDir = tmpdir.path;
tmpdir.refresh();
const tmpCmdFile = path.join(tmpDir, 'test-stdin-from-file-spawn-cmd');
const tmpJsFile = path.join(tmpDir, 'test-stdin-from-file-spawn.js');
fs.writeFileSync(tmpCmdFile, 'echo hello');
fs.writeFileSync(tmpJsFile, `
'use strict';
const { spawn } = require('child_process');
// Reference the object to invoke the getter
process.stdin;
setTimeout(() => {
let ok = false;
const child = spawn(process.env.SHELL || '${defaultShell}',
[], { stdio: ['inherit', 'pipe'] });
child.stdout.on('data', () => {
ok = true;
});
child.on('close', () => {
process.exit(ok ? 0 : -1);
});
}, 100);
`);
execSync(`${process.argv[0]} ${tmpJsFile} < ${tmpCmdFile}`);

View file

@ -268,3 +268,13 @@ testDestroy((opts) => new Writable({
assert.strictEqual(constructed, true);
}));
}
{
// Construct should not cause stream to read.
new Readable({
construct: common.mustCall((callback) => {
callback();
}),
read: common.mustNotCall()
});
}