Merge branch 'PHP-7.4'

* PHP-7.4:
  Fixed bug #78989

diff --cc Zend/zend_inheritance.c
index 3a9deabb06da3d5c02c7b69410408e9ccba535d3,442ab8afc14b8b6c97a336e9320f155f9cc41abc..60d7751e2d2b0f3786b59e7289b898587cc3360e
--- 1/Zend/zend_inheritance.c
--- 2/Zend/zend_inheritance.c
+++ b/Zend/zend_inheritance.c
@@@ -2210,8 -2237,11 +2210,10 @@@ typedef struct 
        union {
                zend_class_entry *dependency_ce;
                struct {
-                       const zend_function *parent_fn;
-                       const zend_function *child_fn;
+                       /* Traits may use temporary on-stack functions during inheritance checks,
+                        * so use copies of functions here as well. */
+                       zend_function parent_fn;
+                       zend_function child_fn;
 -                      zend_bool always_error;
                };
                struct {
                        const zend_property_info *parent_prop;
@@@ -2263,8 -2294,9 +2265,8 @@@ static void add_compatibility_obligatio
        HashTable *obligations = get_or_init_obligations_for_class(ce);
        variance_obligation *obligation = emalloc(sizeof(variance_obligation));
        obligation->type = OBLIGATION_COMPATIBILITY;
-       obligation->child_fn = child_fn;
-       obligation->parent_fn = parent_fn;
+       obligation->child_fn = *child_fn;
+       obligation->parent_fn = *parent_fn;
 -      obligation->always_error = always_error;
        zend_hash_next_index_insert_ptr(obligations, obligation);
  }
  
@@@ -2292,14 -2324,18 +2294,14 @@@ static int check_variance_obligation(zv
                        return ZEND_HASH_APPLY_KEEP;
                }
        } else if (obligation->type == OBLIGATION_COMPATIBILITY) {
 -              zend_string *unresolved_class;
                inheritance_status status = zend_do_perform_implementation_check(
-                       obligation->child_fn, obligation->parent_fn);
 -                      &unresolved_class, &obligation->child_fn, &obligation->parent_fn);
 -
++                      &obligation->child_fn, &obligation->parent_fn);
                if (UNEXPECTED(status != INHERITANCE_SUCCESS)) {
                        if (EXPECTED(status == INHERITANCE_UNRESOLVED)) {
                                return ZEND_HASH_APPLY_KEEP;
                        }
                        ZEND_ASSERT(status == INHERITANCE_ERROR);
-                       emit_incompatible_method_error(obligation->child_fn, obligation->parent_fn, status);
 -                      emit_incompatible_method_error_or_warning(
 -                              &obligation->child_fn, &obligation->parent_fn, status, unresolved_class,
 -                              obligation->always_error);
++                      emit_incompatible_method_error(&obligation->child_fn, &obligation->parent_fn, status);
                }
                /* Either the compatibility check was successful or only threw a warning. */
        } else {
@@@ -2362,14 -2398,17 +2364,14 @@@ static void report_variance_errors(zend
        ZEND_ASSERT(obligations != NULL);
  
        ZEND_HASH_FOREACH_PTR(obligations, obligation) {
 -              inheritance_status status;
 -              zend_string *unresolved_class;
 -
                if (obligation->type == OBLIGATION_COMPATIBILITY) {
 -                      /* Just used to fetch the unresolved_class in this case. */
 -                      status = zend_do_perform_implementation_check(
 -                              &unresolved_class, &obligation->child_fn, &obligation->parent_fn);
 +                      /* Just used to populate the delayed_autoloads table,
 +                       * which will be used when printing the "unresolved" error. */
 +                      inheritance_status status = zend_do_perform_implementation_check(
-                               obligation->child_fn, obligation->parent_fn);
++                              &obligation->child_fn, &obligation->parent_fn);
                        ZEND_ASSERT(status == INHERITANCE_UNRESOLVED);
 -                      emit_incompatible_method_error_or_warning(
 -                              &obligation->child_fn, &obligation->parent_fn,
 -                              status, unresolved_class, obligation->always_error);
 +                      emit_incompatible_method_error(
-                               obligation->child_fn, obligation->parent_fn, status);
++                              &obligation->child_fn, &obligation->parent_fn, status);
                } else if (obligation->type == OBLIGATION_PROPERTY_COMPATIBILITY) {
                        emit_incompatible_property_error(obligation->child_prop, obligation->parent_prop);
                } else {