kernel32: Make GetEnvironmentStringsW returns a copy of the environment.

There are certain applications which try to traverse the environement being returned, but this is problematic since they cannot acquire the PEB Lock (i.e cl.exe on Visual Studio 14.15) . Signed-off-by: Jon Doron <arilou@gmail.com> Signed-off-by: Alexandre Julliard <julliard@winehq.org>

kernel32: Make GetEnvironmentStringsW returns a copy of the environment.
be25d225 · Jon Doron · Alexandre Julliard · 42683dd1 · be25d225 · be25d225
Commit be25d225 authored Mar 18, 2019 by Jon Doron Committed by Alexandre Julliard Mar 20, 2019
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Showing with 31 additions and 2 deletions

environ.c dlls/kernel32/environ.c +16 -2

environ.c dlls/kernel32/tests/environ.c +15 -0

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--- a/dlls/kernel32/environ.c
+++ b/dlls/kernel32/environ.c
@@ -139,7 +139,21 @@ LPSTR WINAPI GetEnvironmentStringsA(void)
 */
 LPWSTR WINAPI GetEnvironmentStringsW(void)
 {
-    return NtCurrentTeb()->Peb->ProcessParameters->Environment;
+    LPWSTR ret, ptrW;
+    unsigned len;
+
+    RtlAcquirePebLock();
+
+    ptrW = NtCurrentTeb()->Peb->ProcessParameters->Environment;
+    while (*ptrW) ptrW += strlenW(ptrW) + 1;
+    ptrW++;
+
+    len = (ptrW - NtCurrentTeb()->Peb->ProcessParameters->Environment) * sizeof(WCHAR);
+    ret = HeapAlloc(GetProcessHeap(), 0, len);
+    if (ret) memcpy(ret, NtCurrentTeb()->Peb->ProcessParameters->Environment, len);
+
+    RtlReleasePebLock();
+    return ret;
 }


@@ -157,7 +171,7 @@ BOOL WINAPI FreeEnvironmentStringsA( LPSTR ptr )
 */
 BOOL WINAPI FreeEnvironmentStringsW( LPWSTR ptr )
 {
-    return TRUE;
+    return HeapFree( GetProcessHeap(), 0, ptr );
 }



--- a/dlls/kernel32/tests/environ.c
+++ b/dlls/kernel32/tests/environ.c
@@ -554,6 +554,20 @@ static void test_GetComputerNameExW(void)
    HeapFree(GetProcessHeap(), 0, nameW);
 }

+static void test_GetEnvironmentStringsW(void)
+{
+    PWCHAR env1;
+    PWCHAR env2;
+
+    env1 = GetEnvironmentStringsW();
+    env2 = GetEnvironmentStringsW();
+    ok(env1 != env2 ||
+       broken(env1 == env2), /* NT <= 5.1 */
+       "should return different copies\n");
+    FreeEnvironmentStringsW(env1);
+    FreeEnvironmentStringsW(env2);
+}
+
 START_TEST(environ)
 {
    init_functionpointers();
@@ -565,4 +579,5 @@ START_TEST(environ)
    test_GetComputerName();
    test_GetComputerNameExA();
    test_GetComputerNameExW();
+    test_GetEnvironmentStringsW();
 }