From 460bbc8ebe70b700a9eb47884dc6a4866db2dd5c Mon Sep 17 00:00:00 2001
From: Nikita Popov <nikita.ppv@gmail.com>
Date: Sun, 24 Apr 2022 18:20:46 +0200
Subject: [PATCH] Add clarifying comment for SEND_VAL usage

This confused me for a bit, because we're using SEND_VAL here to
potentially perform a by-ref SEND, while it is usually used for
by-val SENDs.
---
 Zend/zend_compile.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index a2098a4decc..e0ee212a6b1 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -3487,6 +3487,9 @@ static uint32_t zend_compile_args(
 					if (ARG_MUST_BE_SENT_BY_REF(fbc, arg_num)) {
 						opcode = ZEND_SEND_VAR_NO_REF;
 					} else if (ARG_MAY_BE_SENT_BY_REF(fbc, arg_num)) {
+						/* For IS_VAR operands, SEND_VAL will pass through the operand without
+						 * dereferencing, so it will use a by-ref pass if the call returned by-ref
+						 * and a by-value pass if it returned by-value. */
 						opcode = ZEND_SEND_VAL;
 					} else {
 						opcode = ZEND_SEND_VAR;