browse: handle object deletion when paths are untracked

If an existing path becomes untracked git-cola would try to send a
signal to a dead C++ object and crash:

	RuntimeError: wrapped C/C++ object of type
	              GitRepoNameItem has been deleted
	error: git-cola died of signal 6

Disconnect signals when connecting to the global GitRepoEntry instances
so that no signals are ever delivered to deleted objects.

Signed-off-by: David Aguilar <davvid@gmail.com>

cola/models/browse.py

@@ -456,9 +456,11 @@ def __init__(self, column, path, parent, runtask):
         self.setEditable(False)
         entry = GitRepoEntryStore.entry(path, parent, runtask)
         if column == Columns.STATUS:
+            qtutils.disconnect(entry.status)
             entry.status.connect(self.set_status, type=Qt.QueuedConnection)
         else:
             signal = getattr(entry, column)
+            qtutils.disconnect(signal)
             signal.connect(self.setText, type=Qt.QueuedConnection)
 
     def set_status(self, data):

cola/qtutils.py

@@ -26,6 +26,14 @@
 SKIPPED = object()
 
 
+def disconnect(signal):
+    """Disconnect signal from all slots"""
+    try:
+        signal.disconnect()
+    except TypeError:  # allow unconnected slots
+        pass
+
+
 def connect_action(action, fn):
     """Connect an action to a function"""
     action.triggered[bool].connect(lambda x: fn())

share/doc/git-cola/relnotes.rst

@@ -14,6 +14,16 @@ Clone the git-cola repo to get the latest development version:
 
 ``git clone git://github.com/git-cola/git-cola.git``
 
+.. _v2.11:
+
+git-cola v2.11 (beta)
+=====================
+
+Fixes
+=====
+* Properly handle the case where an existing file is untracked using
+  the File Browser.
+
 .. _v2.10:
 
 git-cola v2.10