Fix bug where TABVIEW would have two subviews. You can't change a PTYTab's...

Fix bug where TABVIEW would have two subviews. You can't change a PTYTab's root_; it's bound for life.

PTYTab.h

@@ -92,6 +92,9 @@
 @property(nonatomic, assign, getter=isBroadcasting) BOOL broadcasting;
+// uniqueId lazily auto-assigns a unique id unless you assign it a value first. It is never 0.
+@property(nonatomic, assign) int uniqueId;
+
 // init/dealloc
 - (id)initWithSession:(PTYSession*)session;
 - (id)initWithRoot:(NSSplitView*)root;
@@ -248,7 +251,6 @@
 - (BOOL)canMoveCurrentSessionDividerBy:(int)direction horizontally:(BOOL)horizontally;
 - (void)swapSession:(PTYSession *)session1 withSession:(PTYSession *)session2;
-- (int)uniqueId;
 - (NSIndexPath *)pathToSplitPaneWithSession:(PTYSession *)session;
 - (BOOL)insertSession:(PTYSession *)aSession
                atPath:(NSIndexPath *)indexPath

PTYTab.m

@@ -2075,18 +2075,23 @@ static NSString* FormatRect(NSRect r) {
         aSession.tab = self;
     }
     for (PTYSplitView *splitview in [self splitters]) {
-        splitview.delegate = nil;
+        if (splitview != root_) {
+            splitview.delegate = nil;
+        }
     }
     for (PTYSplitView *splitview in [tabToGut splitters]) {
-        splitview.delegate = self;
+        if (splitview != tabToGut->root_) {
+            splitview.delegate = self;
+        }
+    }
+
+    while (root_.subviews.count) {
+        [root_.subviews[0] removeFromSuperview];
+    }
+    while (tabToGut->root_.subviews.count) {
+        [root_ addSubview:tabToGut->root_.subviews[0]];
     }
-    NSSplitView *temp = root_;
-    root_ = tabToGut->root_;
-    root_.delegate = self;
-    [[[self tabViewItem] tabView] addSubview:root_];
-    [temp removeFromSuperview];
-    tabToGut->root_ = temp;
 }
 - (void)enableFlexibleView

PseudoTerminal.m

@@ -4528,6 +4528,7 @@ NSString *kSessionsKVCKey = @"sessions";
                                   inTerminal:self
                              hasFlexibleView:NO
                                      viewMap:theMap];
+    tab.uniqueId = tabUniqueId;
     for (id theKey in theMap) {
         PTYSession *session = theMap[theKey];
         assert([session revive]);  // TODO: This isn't guarantted