[PATCH] Cygwin: build_env: fix off-by-one bug when re-adding PATH

[Corinna Vinschen]

On Aug  7 10:51, Michael Haubenwallner wrote:
> Adding default winvar 'PATH=C:\cygwin64\binZ' to an environment that is
> already allocated for 'SYSTEMROOT=ZWINDIR=Z', we need to count that
> trailing (Z)ero as well.  Otherwise we trigger this assertion failure:
> 
> $ /bin/env -i SYSTEMROOT= WINDIR= /bin/env
> assertion "(s - envblock) <= tl" failed: file "/home/corinna/src/cygwin/cygwin-3.0.7/cygwin-3.0.7-1.x86_64/src/newlib-cygwin/winsup/cygwin/environ.cc", line 1302, function: char** build_env(const char* const*, WCHAR*&, int&, bool, HANDLE)
> Aborted (core dumped)
> ---
>  winsup/cygwin/environ.cc | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/winsup/cygwin/environ.cc b/winsup/cygwin/environ.cc
> index 124842734..8fa01b2d5 100644
> --- a/winsup/cygwin/environ.cc
> +++ b/winsup/cygwin/environ.cc
> @@ -1295,7 +1295,7 @@ build_env (const char * const *envp, PWCHAR &envblock, int &envc,
>  	 during execve. */
>        if (!saw_PATH)
>  	{
> -	  new_tl += cygheap->installation_dir.Length / sizeof (WCHAR) + 5;
> +	  new_tl += cygheap->installation_dir.Length / sizeof (WCHAR) + 5 + 1;
>  	  if (new_tl > tl)
>  	    tl = raise_envblock (new_tl, envblock, s);
>  	  s = wcpcpy (wcpcpy (s, L"PATH="),
> -- 
> 2.21.0

Pushed.


Thanks,
Corinna

-- 
Corinna Vinschen
Cygwin Maintainer
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