[Patch] Make getenv() functional before the environment is initialized

[Pierre A. Humblet]

----- Original Message ----- 
From: "Christopher Faylor" <cgf-no-personal-reply-please@cygwin.com>
To: <cygwin-patches@cygwin.com>
Sent: Friday, April 21, 2006 3:13 PM
Subject: Re: [Patch] Make getenv() functional before the environment is 
initialized


> On Fri, Apr 21, 2006 at 02:52:06PM -0400, Pierre A. Humblet wrote:
>>
>>In particular GetEnvironmentStrings returns a big block of
>>storage that should be free (which we can't do), and that is
>>going to be lost on a fork, potentially leading to trouble.
>>
>>Thus I have another implementation using GetEnvironmentValue
>>and cmalloc. (with HEAP_1_MAX, so that it will be released
>>on the next exec).
>>I also take advantage of spawn_info, whose existence I had forgotten.
>>Overall it's also simpler.
>>
>>Here is another patch, sorry for not sending this earlier.
>
> I don't see any reason to permanently allocate memory with cmalloc.
>
> I think that using GetEnvironmentStrings is still the right choice here.
> You just have to make sure that it gets freed.  I'm going to check in a
> cleanup of getearly which will move the rawenv variable to a static
> which will potentially be used by environ_init.  Then environ_init will
> free it if it has been previously set.

But doesn't the program then have a pointer to memory that has been freed?
That pointer can also be accessed after forks.

Pierre