Disowned command killed when piping NUL character

Disowned command killed when piping NUL character

[Johan Grande]

I notice the following inconsistency in behavior. Is it indeed a bug? 
The async job with the \0 doesn't print "hello" while the other two 
commands do.

% { print |read line; echo hello } &!
% hello

% { print '\0'|read -d $'\0' line; echo hello } &!
% print '\0'|read -d $'\0' line; echo hello
hello

With zsh 5.8.1 (x86_64-ubuntu-linux-gnu) and an empty ~/.zshrc.

-- 
Johan

Re: Disowned command killed when piping NUL character

[Bart Schaefer]

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On Wed, Jul 19, 2023 at 3:29 PM Johan Grande <nahoj@crans.org> wrote:

> I notice the following inconsistency in behavior. Is it indeed a bug?
>

If you change "&!" to just "&" you'll observe that the "read" is being
stopped by a TTOU signal.

This is happening because it's trying to reset the terminal from "cooked"
to "raw" mode on the assumption that it's reading from the shell's standard
input rather than the piped input.  The same thing will happen with the
"-s" option.

This probably should be considered a bug.  I believe the below is all
that's necessary, but would appreciate another eyeball.

diff --git a/Src/builtin.c b/Src/builtin.c
index 669a47092..1568cf44c 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -6483,7 +6483,7 @@ bin_read(char *name, char **args, Options ops,
UNUSED(int func))
     } else
  readfd = izle = 0;

-    if (OPT_ISSET(ops,'s') && SHTTY != -1) {
+    if (OPT_ISSET(ops,'s') && SHTTY == readfd) {
  struct ttyinfo ti;
  gettyinfo(&ti);
  saveti = ti;
@@ -6531,7 +6531,7 @@ bin_read(char *name, char **args, Options ops,
UNUSED(int func))
         delim = (unsigned char) ((delimstr[0] == Meta) ?
  delimstr[1] ^ 32 : delimstr[0]);
 #endif
- if (SHTTY != -1) {
+ if (SHTTY == readfd) {
     struct ttyinfo ti;
     gettyinfo(&ti);
     if (! resettty) {
@@ -6691,7 +6691,7 @@ bin_read(char *name, char **args, Options ops,
UNUSED(int func))
     /* dispose of result appropriately, etc. */
     if (isem)
  while (val > 0 && read(SHTTY, &d, 1) == 1 && d != '\n');
-    else {
+    else if (resettty) {
  settyinfo(&shttyinfo);
  resettty = 0;
     }

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