node 10.2.0+ turning off stty echo when using process.stdin.setRawMode()

[jdx]

• Version: 10.2.0
• Platform: MacOS
• Subsystem: Unsure right now

Starting with node 10.2.0 it is behaving as if I'm running stty -echo and hides the echo output when using heroku run and typing characters in. Node 10.3.0 and 10.3.1 also have the issue, but 10.1.0 and lower does not.

Right now I'm working on providing a simpler example that does not involve the Heroku CLI. I'm assuming this is something related to using .setRawMode() but will update when I have more information.

Update: Here is a simpler example: node -e "process.stdin.setRawMode(true)" in bash. It sets stty -echo.

If you run this in node 10.1.0, nothing happens. If you run it in 10.2.0 in bash, it will turn echo off.

[addaleax]

Thanks for reporting this! Do you have any reproduction that doesn’t involve extra setup, or alternatively a standalone reproduction that you could share somewhere?

[jdx]

just run node -e "process.stdin.setRawMode(true)" in bash

[jdx]

I thought it happened when I ran process.stdin.unref(), but it seems that all you need is process.stdin.setRawMode(true)

[jdx]

Here this shows the full behavior:

bash-4.4$ node -v; node -e "process.stdin.setRawMode(true)"; stty
v10.1.0
speed 9600 baud;
lflags: -icanon -isig -iexten echoe echoke echoctl
iflags: -icrnl -ixon iutf8 -brkint
oflags: -oxtabs
cflags: cs8 -parenb
bash-4.4$ n 10.2.0
bash-4.4$ node -v; node -e "process.stdin.setRawMode(true)"; stty
v10.2.0
speed 9600 baud;
lflags: -icanon -isig -iexten -echo echoe echoke echoctl
iflags: -icrnl -ixon iutf8 -brkint
oflags: -oxtabs
cflags: cs8 -parenb

[addaleax]

This was caused by my 17e289e (#19377). My initial guess would be that closing the libuv handle for stdin closes the corresponding file descriptor and leaves libuv unable to reset the state for that file descriptor in uv_tty_reset_mode().

[jdx]

what a shame! seems you worked hard on that PR!

[addaleax]

I did. 😄 I don’t think we need a full revert here, but addressing this properly is not exactly trivial either. The quick-and-probably-good-enough solution to this problem would be this:

--- a/src/node.cc
+++ b/src/node.cc
@@ -4289,6 +4289,7 @@ inline int Start(Isolate* isolate, IsolateData* isolate_data,
   WaitForInspectorDisconnect(&env);
 
   env.set_can_call_into_js(false);
+  uv_tty_reset_mode();
   env.RunCleanup();
   RunAtExit(&env);
 

It does address the problem locally for me, and I think I’ll open a PR with it in a bit.