diff --git a/NEWS b/NEWS
index bf00d8f663b90..be349610ff86f 100644
--- a/NEWS
+++ b/NEWS
@@ -101,6 +101,8 @@ PHP                                                                        NEWS
     while COW violation flag is still set). (alexandre-daubois)
   . Invalid mode values now throw in array_filter() instead of being silently
     defaulted to 0. (Jorg Sowa)
+  . Fixed bug GH-21058 (error_log() crashes with message_type 3 and
+    null destination). (David Carlier)
 
 - Streams:
   . Added so_keepalive, tcp_keepidle, tcp_keepintvl and tcp_keepcnt stream
diff --git a/Zend/tests/ast/gh21072.phpt b/Zend/tests/ast/gh21072.phpt
new file mode 100644
index 0000000000000..1ffd0518eaea9
--- /dev/null
+++ b/Zend/tests/ast/gh21072.phpt
@@ -0,0 +1,17 @@
+--TEST--
+(unset) cast must not be allowed in constant expressions
+--CREDITS--
+Viet Hoang Luu (@vi3tL0u1s)
+--FILE--
+<?php
+try {
+    class C {
+        public $p = (unset) C::class;
+    }
+    new C;
+} catch (Error $e) {
+    echo $e->getMessage();
+}
+?>
+--EXPECTF--
+Fatal error: The (unset) cast is no longer supported in %s on line %d
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 1ce921d4fec2f..fb04387a0045a 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -12564,6 +12564,9 @@ static void zend_eval_const_expr(zend_ast **ast_ptr) /* {{{ */
 			zend_eval_const_expr(&ast->child[1]);
 			return;
 		case ZEND_AST_CAST:
+			if (ast->attr == IS_NULL) {
+				zend_error_noreturn(E_COMPILE_ERROR, "The (unset) cast is no longer supported");
+			}
 			zend_eval_const_expr(&ast->child[0]);
 			if (ast->child[0]->kind == ZEND_AST_ZVAL
 			 && zend_try_ct_eval_cast(&result, ast->attr, zend_ast_get_zval(ast->child[0]))) {
diff --git a/ext/date/php_date.c b/ext/date/php_date.c
index 8f98589b2b47e..e462b70d2cff2 100644
--- a/ext/date/php_date.c
+++ b/ext/date/php_date.c
@@ -370,9 +370,7 @@ static int date_object_compare_timezone(zval *tz1, zval *tz2);
 
 /* {{{ Module struct */
 zend_module_entry date_module_entry = {
-	STANDARD_MODULE_HEADER_EX,
-	NULL,
-	NULL,
+	STANDARD_MODULE_HEADER,
 	"date",                     /* extension name */
 	ext_functions,              /* function list */
 	PHP_MINIT(date),            /* process startup */
diff --git a/ext/standard/basic_functions.c b/ext/standard/basic_functions.c
index dc6146aec9d9c..1d7f2c1a9b59d 100644
--- a/ext/standard/basic_functions.c
+++ b/ext/standard/basic_functions.c
@@ -1369,7 +1369,7 @@ PHPAPI zend_result _php_error_log(int opt_err, const zend_string *message, const
 			return FAILURE;
 
 		case 3:		/*save to a file */
-			stream = php_stream_open_wrapper(ZSTR_VAL(opt), "a", REPORT_ERRORS, NULL);
+			stream = php_stream_open_wrapper(opt ? ZSTR_VAL(opt) : NULL, "a", REPORT_ERRORS, NULL);
 			if (!stream) {
 				return FAILURE;
 			}
diff --git a/ext/standard/tests/general_functions/gh21058.phpt b/ext/standard/tests/general_functions/gh21058.phpt
new file mode 100644
index 0000000000000..598625a2017eb
--- /dev/null
+++ b/ext/standard/tests/general_functions/gh21058.phpt
@@ -0,0 +1,13 @@
+--TEST--
+GH-21058 (error_log() crash with null destination and message type 3)
+--FILE--
+<?php
+
+try {
+	error_log("test", 3, null);
+} catch (\ValueError $e) {
+	echo $e->getMessage(), PHP_EOL;
+}
+?>
+--EXPECT--
+Path must not be empty