GNU bug report logs - #13070
Use putenv+unsetenv instead of modifying environ directly

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Message #22 received at 13070-done <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: 13070-done <at> debbugs.gnu.org, fabrice.popineau <at> gmail.com
Subject: Re: Use putenv+unsetenv instead of modifying environ directly
Date: Sat, 08 Dec 2012 09:20:57 -0800

On 12/08/2012 03:42 AM, Eli Zaretskii wrote:
> Shouldn't we refrain from signaling memory_full when errno is EINVAL?
> I'd suggest an eassert in that case.  memory_full will emit a
> misleading diagnostic.

errno cannot be EINVAL, at least not on a POSIXish host:
all strings are allowed as arguments to putenv.
If Microsoft platforms are different it would
make sense to put in an eassert, in w32.c presumably.

I did see a minor problem in the w32.c implementation of unsetenv:

  /* MS docs says an environment variable cannot be longer than 32K.  */
  if (name_len > 32767)
    {
      errno = ENOMEM;
      return -1;
    }

unsetenv should return 0 in that case, not -1, since
the variable cannot possibly be in the environment.
This bug doesn't affect Emacs so it's not a pressing one.

I committed the patch as trunk bzr 111158 and am marking
this bug as fixed.

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