Fix bug #65579 (Using traits with get_class_methods causes segfault).

Specifically, this checks if there are trait aliases defined in the class scope
before attempting to dereference the first trait alias. This handles the case
where a trait alias was used in a child trait but no aliases exist in the
concrete class.

1 files changed, 9 insertions, 8 deletions

diff --git a/Zend/zend_API.c b/Zend/zend_API.c
index 90d27b7987..870a9b6480 100644
--- a/Zend/zend_API.c
+++ b/Zend/zend_API.c
@@ -3917,15 +3917,16 @@ ZEND_API const char* zend_find_alias_name(zend_class_entry *ce, const char *name
 {
 	zend_trait_alias *alias, **alias_ptr;
 
-	alias_ptr = ce->trait_aliases;
-	alias = *alias_ptr;
-	while (alias) {
-		if (alias->alias_len == len &&
-		    !strncasecmp(name, alias->alias, alias->alias_len)) {
-			return alias->alias;
-		}
-		alias_ptr++;
+	if (alias_ptr = ce->trait_aliases) {
 		alias = *alias_ptr;
+		while (alias) {
+			if (alias->alias_len == len &&
+				!strncasecmp(name, alias->alias, alias->alias_len)) {
+				return alias->alias;
+			}
+			alias_ptr++;
+			alias = *alias_ptr;
+		}
 	}
 
 	return name;