204494 - Provide PR_UnsetEnv()

Status: NEW

(NSPR :: NSPR, enhancement)

Description

[Kenneth Herron]

NSPR provides a function called PR_SetEnv() to create/change an environment
variable. However, there's no documented method for removing a variable from the
environment.

prenv.h notes correctly that the string passed to PR_SetEnv() must be
persistant, because the function can be implemented through putenv() which
incorporates the original buffer into the environment. This is true even if the
buffer contains "NAME=", i.e. the caller is attempting to invalidate the envvar.

This is a problem for a module that wants to create an environment variable and
then remove it later. After creating a variable the buffer containing the
variable can be swapped for a new one, but there's no way to completely withdraw
memory controlled by the module from the environment, e.g. as a prelude to
unloading the module from memory. See bug 194761 comment 7 and later for a
module affected by this.

Comment 1

[BugBot [:suhaib / :marco]]

The bug assignee is inactive on Bugzilla, so the assignee is being reset.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/98bf5b032191
https://hg.mozilla.org/integration/autoland/rev/225a7cdcdab7
Revert "Bug 204494, Bug 2041004 - Add <select> pseudo elements to devtools style inspector r=devtools-reviewers,nchevobbe"

Comment 3

[Kai Engert [:KaiE:]]

I guess the mention of 204494 in that commit was a mistake.

Comment 4

[Cristian Tuns]

Yes it was a mistake, instead of this bug in the commit it should have been this https://bugzilla.mozilla.org/show_bug.cgi?id=2044945