2 files changed, 33 insertions, 0 deletions
diff --git a/plumbing/protocol/packp/capability/list.go b/plumbing/protocol/packp/capability/list.go
index ff8d4a4..7197d36 100644
--- a/plumbing/protocol/packp/capability/list.go
+++ b/plumbing/protocol/packp/capability/list.go
@@ -145,6 +145,23 @@ func (l *List) Supports(capability Capability) bool {
 	return ok
 }
 
+// Delete deletes a capability from the List
+func (l *List) Delete(capability Capability) {
+	if !l.Supports(capability) {
+		return
+	}
+
+	delete(l.m, capability)
+	for i, c := range l.sort {
+		if c != string(capability) {
+			continue
+		}
+
+		l.sort = append(l.sort[:i], l.sort[i+1:]...)
+		return
+	}
+}
+
 // String generates the capabilities strings, the capabilities are sorted in
 // insertion order
 func (l *List) String() string {
diff --git a/plumbing/protocol/packp/capability/list_test.go b/plumbing/protocol/packp/capability/list_test.go
index eeb3173..d6aac16 100644
--- a/plumbing/protocol/packp/capability/list_test.go
+++ b/plumbing/protocol/packp/capability/list_test.go
@@ -97,6 +97,22 @@ func (s *SuiteCapabilities) TestGetEmpty(c *check.C) {
 	c.Assert(cap.Get(Agent), check.HasLen, 0)
 }
 
+func (s *SuiteCapabilities) TestDelete(c *check.C) {
+	cap := NewList()
+	cap.Delete(SymRef)
+
+	err := cap.Add(Sideband)
+	c.Assert(err, check.IsNil)
+	err = cap.Set(SymRef, "bar")
+	c.Assert(err, check.IsNil)
+	err = cap.Set(Sideband64k)
+	c.Assert(err, check.IsNil)
+
+	cap.Delete(SymRef)
+
+	c.Assert(cap.String(), check.Equals, "side-band side-band-64k")
+}
+
 func (s *SuiteCapabilities) TestAdd(c *check.C) {
 	cap := NewList()
 	err := cap.Add(SymRef, "foo", "qux")