- When we drop an exclude pattern, we need to recrawl the entire FS tree to
  pick up those files that we previously ignored
- DirectoryPrivate.SetAllToUnknown_Unlocked needs to consider the situation
  where there are no children
- When examining directory children, if ScanOne_Unlocked finds that we already
  know about the child, it should check the state of the child to see if it
  needs a scan anyway.
- FSM.SetAllToUnknown should fire off a scan request so that everything gets
  rescanned/recrawled

The end result of this is that FSM.SetAllToUnknown now does the right thing,
rather than not doing much at all - this means that inotify queue overflows
will now be handled correctly.

Index: FileSystemQueryable/FileNameFilter.cs
===================================================================
RCS file: /cvs/gnome/beagle/beagled/FileSystemQueryable/FileNameFilter.cs,v
retrieving revision 1.18
diff -u -B -p -r1.18 FileNameFilter.cs
--- FileSystemQueryable/FileNameFilter.cs	5 Jul 2005 21:12:05 -0000	1.18
+++ FileSystemQueryable/FileNameFilter.cs	17 Jul 2005 23:36:02 -0000
@@ -165,17 +165,28 @@ namespace Beagle.Daemon.FileSystemQuerya
 		private void OnConfigurationChanged (Conf.Section section)
 		{
 			IList excludes_to_add, excludes_to_remove;
+			bool clear_fs_state = false;
 
 			ArrayFu.IntersectListChanges (Conf.Indexing.Excludes, excludes, out excludes_to_add, out excludes_to_remove);
 
-			foreach (ExcludeItem exclude in excludes_to_remove)
+			foreach (ExcludeItem exclude in excludes_to_remove) {
+				if (exclude.Type == ExcludeType.Pattern)
+					clear_fs_state = true;
 				RemoveExclude (exclude);
+			}
 
 			foreach (ExcludeItem exclude in excludes_to_add)
 				AddExclude (exclude);
 
-			// FIXME: Send a re-scan event here when ignore patterns are updated
-			// and do a model.Remove/Add on the directories in question
+			// If an exclude pattern is removed, we need to recrawl everything
+			// so that we can index those files which were previously ignored.
+			if (clear_fs_state)
+				model.SetAllToUnknown ();
+
+			// FIXME: When an exclude path/pattern is added, we need to deindex
+			// the files in question.
+			// FIXME: When an exclude path is removed, we need to recrawl that
+			// particular path.
 		}
 
 		/////////////////////////////////////////////////////////////
Index: FileSystemQueryable/FileSystemModel.cs
===================================================================
RCS file: /cvs/gnome/beagle/beagled/FileSystemQueryable/FileSystemModel.cs,v
retrieving revision 1.23
diff -u -B -p -r1.23 FileSystemModel.cs
--- FileSystemQueryable/FileSystemModel.cs	5 Jul 2005 21:12:05 -0000	1.23
+++ FileSystemQueryable/FileSystemModel.cs	17 Jul 2005 23:36:03 -0000
@@ -397,6 +397,8 @@ namespace Beagle.Daemon.FileSystemQuerya
 			{
 				if (state == State.Clean)
 					state = State.Unknown;
+				if (this.children == null)
+					return;
 				foreach (DirectoryPrivate subdir in this.children.Values)
 					subdir.SetAllToUnknown_Unlocked ();
 			}
@@ -832,8 +834,16 @@ namespace Beagle.Daemon.FileSystemQuerya
 			try {
 				foreach (System.IO.DirectoryInfo subinfo in DirectoryWalker.GetDirectoryInfos (info)) {
 					if (! Ignore (subinfo.FullName)) {
-						if (! priv.HasChildWithName (subinfo.Name))
+						Directory child = priv.GetChildByName (subinfo.Name);
+
+						// We don't know about the child, in which case we need to add it
+						// (AddChild_Unlocked adds it to to_be_scanned)
+						if (child == null)
 							AddChild_Unlocked (priv, subinfo.Name);
+
+						// Or, we already know about the child, but we might want to scan it anyway
+						else if (child.NeedsCrawl)
+							to_be_scanned.Enqueue (child);
 					}
 					if (known_children != null)
 						known_children.Remove (subinfo.Name);
@@ -1010,12 +1020,17 @@ namespace Beagle.Daemon.FileSystemQuerya
 			}
 		}
 
+		// Set entire filesystem state to unknown, and fire a recrawl operation
 		public void SetAllToUnknown ()
 		{
 			lock (big_lock) {
-				foreach (DirectoryPrivate root in roots)
+				foreach (DirectoryPrivate root in roots) {
 					root.SetAllToUnknown_Unlocked ();
+					to_be_scanned.Enqueue (root);
+				}
 			}
+
+			ScanAll ();
 		}
 
 		///////////////////////////////////////////////////////////////////////////