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);
+	if (s) {
 		memcpy(s, var, l1);
 		s[l1] = '=';
 		memcpy(s+l1+1, value, l2);
 		s[l1+l2+1] = 0;
-	if (__putenv(s, 1)) {
+		if (!__putenv(s, 1)) return 0;
+	}
 	free(s);
 	errno = ENOMEM;
 	return -1;
-	}
-	return 0;
 }