ext/standard/crypt.c: handle musl failure tokens

Musl's crypt() returns "*" to indicate failure in contrast with the
"*0" returned by PHP/libxcrypt. This causes test failures, but more
importantly, is a pretty silly thing to expect the user to know.
This commit catches the musl value and turns it into "*0".

Author: orlitzky

ext/standard/crypt.c

@@ -177,7 +177,19 @@ PHPAPI zend_string *php_crypt(const char *password, const int pass_len, const ch
 
 	if (!crypt_res || (salt[0] == '*' && salt[1] == '0')) {
 		return NULL;
-	} else {
+	}
+	else if (!strcmp(crypt_res, "*")) {
+		/* Musl crypt() uses "*" as a failure token rather
+		 * than the "*0" that libxcrypt/PHP use. Our test
+		 * suite in particular looks for "*0" in a few places,
+		 * and it would be annoying to handle both values
+		 * explicitly. It seems wise to abstract this detail
+		 * from the end user: if it's annoying for us, imagine
+		 * how annoying it would be in end-user code; not that
+		 * anyone would think of it. */
+		return NULL;
+	}
+	else {
 		result = zend_string_init(crypt_res, strlen(crypt_res), 0);
 		return result;
 	}