patch 8.1.1827: allocating more memory than needed for extended structs commit https://github.com/vim/vim/commit/47ed553fd5bebfc36eb8aa81686eeaa5a84eccac Author: Bram Moolenaar <Bram@vim.org> Date: Thu Aug 8 20:49:14 2019 +0200 patch 8.1.1827: allocating more memory than needed for extended structs Problem: Allocating more memory than needed for extended structs. Solution: Use offsetof() instead of sizeof(). (Dominique Pelle, closes #4786)

--- a/src/sign.c
+++ b/src/sign.c
@@ -85,7 +85,7 @@ sign_group_ref(char_u *groupname)
     if (HASHITEM_EMPTY(hi))
     {
 	// new group
-	group = alloc(sizeof(signgroup_T) + STRLEN(groupname));
+	group = alloc(offsetof(signgroup_T, sg_name) + STRLEN(groupname) + 1);
 	if (group == NULL)
 	    return NULL;
 	STRCPY(group->sg_name, groupname);