[meld/meld-3-20] dirdiff: Fix sensitivity when cancelling existing folder scans (#499)

[Kai Willadsen <kaiw src gnome org>]

commit 4265b9730a85880807eacb27fd7769e5f88c7624
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Fri Oct 16 07:01:18 2020 +1000

    dirdiff: Fix sensitivity when cancelling existing folder scans (#499)
    
    In situations where we cancel existing folder scan tasks before they're
    finished, we incorrectly didn't clear the _scan_in_progress sentinel
    variable. This could happen when e.g., toggling a file filter button
    before the current scan had completed, and disabled most of our menu
    items (because they're correctly disabled while a scan is running).

 meld/dirdiff.py | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/meld/dirdiff.py b/meld/dirdiff.py
index 9570da37..b5f99f78 100644
--- a/meld/dirdiff.py
+++ b/meld/dirdiff.py
@@ -689,6 +689,7 @@ class DirDiff(MeldDoc, Component):
         self._update_item_state(child)
         self.recompute_label()
         self.scheduler.remove_all_tasks()
+        self._scan_in_progress = 0
         self.recursively_update(Gtk.TreePath.new_first())
         self._update_diffmaps()