[PATCH 2/4] ntdll: Avoid leaking the previous environment in RtlSetCurrentEnvironment().

[Zebediah Figura]

Signed-off-by: Zebediah Figura 
---
 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 71ae48681df..3acf7f52d5b 100644
--- a/dlls/ntdll/env.c
+++ b/dlls/ntdll/env.c
@@ -996,14 +996,21 @@ 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 );
 }