bin/158206: sh(1) doesn't properly return IO errors to conditionals in a script

[Jilles Tjoelker]

The following reply was made to PR bin/158206; it has been noted by GNATS.

From: Jilles Tjoelker <jilles at stack.nl>
To: bug-followup at FreeBSD.org, culrich at csnstores.com
Cc:  
Subject: Re: bin/158206: sh(1) doesn't properly return IO errors to
 conditionals in a script
Date: Sun, 26 Jun 2011 12:41:00 +0200

 Thank you for your bug report.
 
 The below patch should fix the problem. It applies to 9-current only. It
 could be changed to apply to 8-stable but I will not commit this change
 to 8-stable anyway. It is even a bit late for 9.x, one week into code
 slush.
 
 commit 22f46c6d493531fc8df124675598edbfb9eb8130
 Author: Jilles Tjoelker <jilles at stack.nl>
 Date:   Sun Jun 26 12:25:07 2011 +0200
 
     sh: Detect and flag write errors on stdout in builtins.
     
     PR:		bin/158206
 
 diff --git a/bin/sh/eval.c b/bin/sh/eval.c
 index d5da7d3..8330094 100644
 --- a/bin/sh/eval.c
 +++ b/bin/sh/eval.c
 @@ -1000,6 +1000,7 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
  		}
  		handler = &jmploc;
  		redirect(cmd->ncmd.redirect, mode);
 +		outclearerror(out1);
  		/*
  		 * If there is no command word, redirection errors should
  		 * not be fatal but assignment errors should.
 @@ -1015,6 +1016,11 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
  		builtin_flags = flags;
  		exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
  		flushall();
 +		if (outiserror(out1)) {
 +			warning("write error on stdout");
 +			if (exitstatus == 0 || exitstatus == 1)
 +				exitstatus = 2;
 +		}
  cmddone:
  		if (argc > 0)
  			bltinunsetlocale();
 diff --git a/bin/sh/output.c b/bin/sh/output.c
 index b4dab51..d26adce 100644
 --- a/bin/sh/output.c
 +++ b/bin/sh/output.c
 @@ -239,6 +239,20 @@ freestdout(void)
  }
  
  
 +int
 +outiserror(struct output *file)
 +{
 +	return (file->flags & OUTPUT_ERR);
 +}
 +
 +
 +void
 +outclearerror(struct output *file)
 +{
 +	file->flags &= ~OUTPUT_ERR;
 +}
 +
 +
  void
  outfmt(struct output *file, const char *fmt, ...)
  {
 diff --git a/bin/sh/output.h b/bin/sh/output.h
 index 5e3b048..51974d8 100644
 --- a/bin/sh/output.h
 +++ b/bin/sh/output.h
 @@ -66,6 +66,8 @@ void emptyoutbuf(struct output *);
  void flushall(void);
  void flushout(struct output *);
  void freestdout(void);
 +int outiserror(struct output *);
 +void outclearerror(struct output *);
  void outfmt(struct output *, const char *, ...) __printflike(2, 3);
  void out1fmt(const char *, ...) __printflike(1, 2);
  void out2fmt_flush(const char *, ...) __printflike(1, 2);
 diff --git a/tools/regression/bin/sh/errors/write-error1.0 b/tools/regression/bin/sh/errors/write-error1.0
 new file mode 100644
 index 0000000..fcb52e7
 --- /dev/null
 +++ b/tools/regression/bin/sh/errors/write-error1.0
 @@ -0,0 +1,3 @@
 +# $FreeBSD$
 +
 +! echo >&- 2>/dev/null
 
 -- 
 Jilles Tjoelker