GUI control over saved and in-memory history depth

git-svn-id: svn://localhost/ardour2/branches/2.0-ongoing@2486 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 10 insertions, 5 deletions

diff --git a/libs/pbd/undo.cc b/libs/pbd/undo.cc
index d54c6b0fff..f59228082d 100644
--- a/libs/pbd/undo.cc
+++ b/libs/pbd/undo.cc
@@ -152,11 +152,11 @@ UndoHistory::UndoHistory ()
 }
 
 void
-UndoHistory::set_depth (uint32_t d)
+UndoHistory::set_depth (int32_t d)
 {
 	_depth = d;
 
-	while (_depth > 0 && UndoList.size() > _depth) {
+	while (_depth > 0 && UndoList.size() > (uint32_t) _depth) {
 		UndoList.pop_front ();
 	}
 }
@@ -166,7 +166,7 @@ UndoHistory::add (UndoTransaction* const ut)
 {
 	ut->GoingAway.connect (bind (mem_fun (*this, &UndoHistory::remove), ut));
 
-	while (_depth > 0 && UndoList.size() > _depth) {
+	while (_depth > 0 && UndoList.size() > (uint32_t) _depth) {
 		UndoList.pop_front ();
 	}
 
@@ -253,17 +253,22 @@ UndoHistory::clear ()
 }
 
 XMLNode& 
-UndoHistory::get_state (uint32_t depth)
+UndoHistory::get_state (int32_t depth)
 {
     XMLNode *node = new XMLNode ("UndoHistory");
 
     if (depth == 0) {
+
+	    return (*node);
+
+    } else if (depth < 0) {
+
 	    /* everything */
 
 	    for (list<UndoTransaction*>::iterator it = UndoList.begin(); it != UndoList.end(); ++it) {
 		    node->add_child_nocopy((*it)->get_state());
 	    }
-	    
+
     } else {
 
 	    /* just the last "depth" transactions */