From 1f735a4af3aa0af0ee034bbe9eaa7b2f2e13583d Mon Sep 17 00:00:00 2001
From: Gavin Hayes <gavin@computoid.com>
Date: Wed, 17 Aug 2022 17:15:23 -0400
Subject: [PATCH] Prevent NPE after clearenv (#542)
---
libc/mem/putenv.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/libc/mem/putenv.c b/libc/mem/putenv.c
index 4b10da970..c711bbf7b 100644
--- a/libc/mem/putenv.c
+++ b/libc/mem/putenv.c
@@ -16,10 +16,10 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/mem/alg.h"
#include "libc/calls/strace.internal.h"
#include "libc/dce.h"
#include "libc/macros.internal.h"
+#include "libc/mem/alg.h"
#include "libc/mem/internal.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
@@ -57,11 +57,13 @@ static void GrowEnviron(void) {
size_t n, c;
char **a, **b, **p;
a = environ;
- n = GetEnvironLen(a);
+ n = a ? GetEnvironLen(a) : 0;
c = MAX(16ul, n) << 1;
b = calloc(c, sizeof(char *));
- for (p = b; *a;) {
- *p++ = strdup(*a++);
+ if (a) {
+ for (p = b; *a;) {
+ *p++ = strdup(*a++);
+ }
}
__cxa_atexit(FreeEnviron, b, 0);
environ = b;
@@ -75,6 +77,8 @@ int PutEnvImpl(char *s, bool overwrite) {
__cxa_atexit(RestoreOriginalEnvironment, environ, 0);
GrowEnviron();
once = true;
+ } else if (!environ) {
+ GrowEnviron();
}
for (p = s; *p && *p != '='; ++p) {
if (IsWindows()) {