Imported Upstream version 1.3upstream/1.3

3 files changed, 62 insertions, 6 deletions

diff --git a/src/pkg/container/list/example_test.go b/src/pkg/container/list/example_test.go
index 7361212d7..362178401 100644
--- a/src/pkg/container/list/example_test.go
+++ b/src/pkg/container/list/example_test.go
@@ -17,7 +17,7 @@ func Example() {
 	l.InsertBefore(3, e4)
 	l.InsertAfter(2, e1)
 
-	// Iterate through list and and print its contents.
+	// Iterate through list and print its contents.
 	for e := l.Front(); e != nil; e = e.Next() {
 		fmt.Println(e.Value)
 	}
diff --git a/src/pkg/container/list/list.go b/src/pkg/container/list/list.go
index ed2d15a45..0256768ef 100644
--- a/src/pkg/container/list/list.go
+++ b/src/pkg/container/list/list.go
@@ -65,7 +65,7 @@ func New() *List { return new(List).Init() }
 // The complexity is O(1).
 func (l *List) Len() int { return l.len }
 
-// Front returns the first element of list l or nil
+// Front returns the first element of list l or nil.
 func (l *List) Front() *Element {
 	if l.len == 0 {
 		return nil
@@ -180,18 +180,18 @@ func (l *List) MoveToBack(e *Element) {
 }
 
 // MoveBefore moves element e to its new position before mark.
-// If e is not an element of l, or e == mark, the list is not modified.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
 func (l *List) MoveBefore(e, mark *Element) {
-	if e.list != l || e == mark {
+	if e.list != l || e == mark || mark.list != l {
 		return
 	}
 	l.insert(l.remove(e), mark.prev)
 }
 
 // MoveAfter moves element e to its new position after mark.
-// If e is not an element of l, or e == mark, the list is not modified.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
 func (l *List) MoveAfter(e, mark *Element) {
-	if e.list != l || e == mark {
+	if e.list != l || e == mark || mark.list != l {
 		return
 	}
 	l.insert(l.remove(e), mark)
diff --git a/src/pkg/container/list/list_test.go b/src/pkg/container/list/list_test.go
index ee52afe82..4d8bfc2bf 100644
--- a/src/pkg/container/list/list_test.go
+++ b/src/pkg/container/list/list_test.go
@@ -285,3 +285,59 @@ func TestMove(t *testing.T) {
 	checkListPointers(t, l, []*Element{e1, e3, e2, e4})
 	e1, e2, e3, e4 = e1, e3, e2, e4
 }
+
+// Test PushFront, PushBack, PushFrontList, PushBackList with uninitialized List
+func TestZeroList(t *testing.T) {
+	var l1 = new(List)
+	l1.PushFront(1)
+	checkList(t, l1, []interface{}{1})
+
+	var l2 = new(List)
+	l2.PushBack(1)
+	checkList(t, l2, []interface{}{1})
+
+	var l3 = new(List)
+	l3.PushFrontList(l1)
+	checkList(t, l3, []interface{}{1})
+
+	var l4 = new(List)
+	l4.PushBackList(l2)
+	checkList(t, l4, []interface{}{1})
+}
+
+// Test that a list l is not modified when calling InsertBefore with a mark that is not an element of l.
+func TestInsertBeforeUnknownMark(t *testing.T) {
+	var l List
+	l.PushBack(1)
+	l.PushBack(2)
+	l.PushBack(3)
+	l.InsertBefore(1, new(Element))
+	checkList(t, &l, []interface{}{1, 2, 3})
+}
+
+// Test that a list l is not modified when calling InsertAfter with a mark that is not an element of l.
+func TestInsertAfterUnknownMark(t *testing.T) {
+	var l List
+	l.PushBack(1)
+	l.PushBack(2)
+	l.PushBack(3)
+	l.InsertAfter(1, new(Element))
+	checkList(t, &l, []interface{}{1, 2, 3})
+}
+
+// Test that a list l is not modified when calling MoveAfter or MoveBefore with a mark that is not an element of l.
+func TestMoveUnkownMark(t *testing.T) {
+	var l1 List
+	e1 := l1.PushBack(1)
+
+	var l2 List
+	e2 := l2.PushBack(2)
+
+	l1.MoveAfter(e1, e2)
+	checkList(t, &l1, []interface{}{1})
+	checkList(t, &l2, []interface{}{2})
+
+	l1.MoveBefore(e1, e2)
+	checkList(t, &l1, []interface{}{1})
+	checkList(t, &l2, []interface{}{2})
+}