Zebediah Figura : ntdll: Avoid leaking the previous environment in RtlSetCurrentEnvironment().

[Alexandre Julliard]

Module: wine
Branch: stable
Commit: 04d635555a259112e6e0fcb3a6715941f18140f0
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=04d635555a259112e6e0fcb3a6715941f18140f0

Author: Zebediah Figura <z.figura12 at gmail.com>
Date:   Wed May  6 09:40:27 2020 -0500

ntdll: Avoid leaking the previous environment in RtlSetCurrentEnvironment().

Signed-off-by: Zebediah Figura <z.figura12 at gmail.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
(cherry picked from commit e012bd5811784d953d576a4591c7be14234c92b9)
Signed-off-by: Michael Stefaniuc <mstefani at winehq.org>

---

 dlls/ntdll/env.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/dlls/ntdll/env.c b/dlls/ntdll/env.c
index c5175080c4..d7010cf8b7 100644
--- a/dlls/ntdll/env.c
+++ b/dlls/ntdll/env.c
@@ -973,14 +973,21 @@ NTSTATUS WINAPI RtlQueryEnvironmentVariable_U(PWSTR env,
  */
 void WINAPI RtlSetCurrentEnvironment(PWSTR new_env, PWSTR* old_env)
 {
+    WCHAR *prev;
+
     TRACE("(%p %p)\n", new_env, old_env);
 
     RtlAcquirePebLock();
 
-    if (old_env) *old_env = NtCurrentTeb()->Peb->ProcessParameters->Environment;
+    prev = NtCurrentTeb()->Peb->ProcessParameters->Environment;
     NtCurrentTeb()->Peb->ProcessParameters->Environment = new_env;
 
     RtlReleasePebLock();
+
+    if (old_env)
+        *old_env = prev;
+    else
+        RtlDestroyEnvironment( prev );
 }