fix failure to check malloc result in setenv

src/env/setenv.c

@@ -18,14 +18,14 @@ int setenv(const char *var, const char *value, int overwrite)
 	l1 = strlen(var);
 	l2 = strlen(value);
 	s = malloc(l1+l2+2);
-	memcpy(s, var, l1);
-	s[l1] = '=';
-	memcpy(s+l1+1, value, l2);
-	s[l1+l2+1] = 0;
-	if (__putenv(s, 1)) {
-		free(s);
-		errno = ENOMEM;
-		return -1;
+	if (s) {
+		memcpy(s, var, l1);
+		s[l1] = '=';
+		memcpy(s+l1+1, value, l2);
+		s[l1+l2+1] = 0;
+		if (!__putenv(s, 1)) return 0;
 	}
-	return 0;
+	free(s);
+	errno = ENOMEM;
+	return -1;
 }