Fix leak of xmlElementContent

* valid.c:
(xmlCopyDocElementContent):
- Set `tmp->parent` properly to fix a leak that occurs in
  xmlFreeDocElementContent().
- Appears to be a regresion from cee2b3a5f1.

Found by OSS-Fuzz Issue 44509.

1 files changed, 1 insertions, 0 deletions

diff --git a/valid.c b/valid.c
index 9684683a..ed3c8503 100644
--- a/valid.c
+++ b/valid.c
@@ -1052,6 +1052,7 @@ xmlCopyDocElementContent(xmlDocPtr doc, xmlElementContentPtr cur) {
 	    tmp->type = cur->type;
 	    tmp->ocur = cur->ocur;
 	    prev->c2 = tmp;
+	    tmp->parent = prev;
 	    if (cur->name != NULL) {
 		if (dict)
 		    tmp->name = xmlDictLookup(dict, cur->name, -1);