Deprecate using null as an array offset and when calling array_key_exists()

[alexandre-daubois]

Part of #19468

RFC: https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_using_values_null_as_an_array_offset_and_when_calling_array_key_exists

cc @Girgias

[alexandre-daubois]

Still a few tests to fix but we're getting closer

[Girgias]

Thank you! This is okay on my side, but I would like for @nielsdos to confirm that whatever the issue was is now resolved. :)

[Girgias]

@nielsdos @alexandre-daubois is there still something blocking here?

[alexandre-daubois]

Ah yes I missed your comment, PR updated. All good on my side

[Girgias]

Circle CI failures look legit

[edorian]

RM approval 👍, no technical review performed

[nielsdos]

It can still be simplified:

diff --git a/ext/opcache/jit/zend_jit_helpers.c b/ext/opcache/jit/zend_jit_helpers.c
index 261f06068c8..ce48d102234 100644
--- a/ext/opcache/jit/zend_jit_helpers.c
+++ b/ext/opcache/jit/zend_jit_helpers.c
@@ -501,33 +501,17 @@ static void ZEND_FASTCALL zend_jit_fetch_dim_r_helper(zend_array *ht, zval *dim,
 			}
 			ZEND_FALLTHROUGH;
 		case IS_NULL:
-			/* The array may be destroyed while throwing the notice.
-			 * Temporarily increase the refcount to detect this situation. */
-			if (!(GC_FLAGS(ht) & IS_ARRAY_IMMUTABLE)) {
-				GC_ADDREF(ht);
+			retval = zend_hash_find(ht, ZSTR_EMPTY_ALLOC());
+			if (!retval) {
+				ZVAL_NULL(result);
+			} else {
+				ZVAL_COPY_DEREF(result, retval);
 			}
-			execute_data = EG(current_execute_data);
-			opline = EX(opline);
 			zend_error(E_DEPRECATED, "Using null as an array offset is deprecated, use an empty string instead");
-			if (!(GC_FLAGS(ht) & IS_ARRAY_IMMUTABLE) && !GC_DELREF(ht)) {
-				zend_array_destroy(ht);
-				if (opline->result_type & (IS_VAR | IS_TMP_VAR)) {
-					if (EG(exception)) {
-						ZVAL_UNDEF(EX_VAR(opline->result.var));
-					} else {
-						ZVAL_NULL(EX_VAR(opline->result.var));
-					}
-				}
-				return;
-			}
-			if (EG(exception)) {
-				if (opline->result_type & (IS_VAR | IS_TMP_VAR)) {
-					ZVAL_UNDEF(EX_VAR(opline->result.var));
-				}
-				return;
+			if (!retval) {
+				zend_error(E_WARNING, "Undefined array key \"\"");
 			}
-			offset_key = ZSTR_EMPTY_ALLOC();
-			goto str_index;
+			return;
 		case IS_DOUBLE:
 			hval = zend_dval_to_lval(Z_DVAL_P(dim));
 			if (!zend_is_long_compatible(Z_DVAL_P(dim), hval)) {

the write cases are more annoying but this read case works on my machine.

[alexandre-daubois]

Oh right, your last comment in our thread got lost in my notifications, sorry. PR updated and green. Thanks!