core: check that infolist is not NULL in next/prev/reset_item_cursor functions

src/core/wee-infolist.c

@@ -314,6 +314,9 @@ infolist_new_var_time (struct t_infolist_item *item,
 struct t_infolist_item *
 infolist_next (struct t_infolist *infolist)
 {
+    if (!infolist)
+        return NULL;
+
     if (!infolist->ptr_item)
     {
         infolist->ptr_item = infolist->items;
@@ -332,6 +335,9 @@ infolist_next (struct t_infolist *infolist)
 struct t_infolist_item *
 infolist_prev (struct t_infolist *infolist)
 {
+    if (!infolist)
+        return NULL;
+
     if (!infolist->ptr_item)
     {
         infolist->ptr_item = infolist->last_item;
@@ -348,6 +354,9 @@ infolist_prev (struct t_infolist *infolist)
 void
 infolist_reset_item_cursor (struct t_infolist *infolist)
 {
+    if (!infolist)
+        return;
+
     infolist->ptr_item = NULL;
 }
 

tests/unit/core/test-core-infolist.cpp

@@ -314,6 +314,10 @@ TEST(CoreInfolist, Move)
 
     POINTERS_EQUAL(NULL, infolist->ptr_item);
 
+    infolist_next (NULL);
+    infolist_prev (NULL);
+    infolist_reset_item_cursor (NULL);
+
     /* move to first item in infolist */
     POINTERS_EQUAL(infolist->items, infolist_next (infolist));
     POINTERS_EQUAL(infolist->items, infolist->ptr_item);