Fix channel variables on cloned channels (bug #3804)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5222 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/linkedlists.h

@@ -229,21 +229,23 @@ struct {								\
 } while (0)
 
 /*!
-  \brief Inserts a list entry at the tail of a list.
+  \brief Appends a list entry to the tail of a list.
   \param head This is a pointer to the list head structure
-  \param elm This is a pointer to the entry to be inserted.
+  \param elm This is a pointer to the entry to be appended.
   \param field This is the name of the field (declared using AST_LIST_ENTRY())
   used to link entries of this list together.
+
+  Note: The link field in the appended entry is \b not modified, so if it is
+  actually the head of a list itself, the entire list will be appended.
  */
 #define AST_LIST_INSERT_TAIL(head, elm, field) do {			\
-      typeof(elm) curelm = (head)->first;                             \
+      if (!(head)->first) {						\
-      if (!curelm) {                                                  \
+              (head)->first = (elm);					\
-              AST_LIST_INSERT_HEAD(head, elm, field);                 \
       } else {								\
-              while (curelm->field.next!=NULL) {                      \
+              typeof(elm) curelm = (head)->first;			\
+              while (curelm->field.next != NULL)			\
                       curelm = curelm->field.next;			\
-              }                                                       \
+              curelm->field.next = (elm);				\
-              AST_LIST_INSERT_AFTER(curelm, elm, field);              \
       }									\
 } while (0)
 
@@ -272,14 +274,13 @@ struct {								\
  */
 #define AST_LIST_REMOVE(head, elm, field) do {			        \
 	if ((head)->first == (elm)) {					\
-		AST_LIST_REMOVE_HEAD((head), field);			\
+		(head)->first = (elm)->field.next;			\
 	}								\
 	else {								\
 		typeof(elm) curelm = (head)->first;			\
 		while (curelm->field.next != (elm))			\
 			curelm = curelm->field.next;			\
-		curelm->field.next =					\
+		curelm->field.next = (elm)->field.next;			\
-		    curelm->field.next->field.next;			\
 	}								\
 } while (0)