[BUG] builtin echo doesn't check write error

[Vincent Lefevre <vincent@xxxxxxxxxx>]

With zsh 5.8, the builtin echo doesn't check write error.

zira% zsh -c 'echo foo >&-; echo $?'
0

In strace output:

close(1)                                = 0
write(1, "foo\n", 4)                    = -1 EBADF (Bad file descriptor)

No issues with an external echo command:

zira% zsh -c '/bin/echo foo >&-; echo $?'
/bin/echo: write error: Bad file descriptor
1

And with other shells:

zira% sh -c 'echo foo >&-; echo $?'
sh: 1: echo: echo: I/O error
1
zira% bash -c 'echo foo >&-; echo $?'
bash: line 1: echo: write error: Bad file descriptor
1
zira% ksh -c 'echo foo >&-; echo $?'
1
zira% ksh93 -c 'echo foo >&-; echo $?'
1
zira% mksh -c 'echo foo >&-; echo $?'
1
zira% posh -c 'echo foo >&-; echo $?'
1
zira% yash -c 'echo foo >&-; echo $?'
echo: cannot print to the standard output: Bad file descriptor
1

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Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)