Improved fix for #722

This is lot faster

Leo build: 20180223133813

leo/core/commit_timestamp.json

@@ -1,4 +1,4 @@
 {
-    "asctime": "Fri Feb 23 13:25:22 UTC 2018",
-    "timestamp": "20180223132522"
+    "asctime": "Fri Feb 23 13:38:13 UTC 2018",
+    "timestamp": "20180223133813"
 }

leo/core/leoFind.py

@@ -485,14 +485,15 @@ def changeAllCommand(self, event=None):
         self.changeAll()
         # Fixes: #722 replace-all leaves unsaved changed files
         c = self.c
-        def has_dirty_descendant(p):
-            if p.isAnyAtFileNode():
-                for p1 in p.self_and_subtree():
-                    if p1.v.isDirty(): return True
-            return False
-        for p in c.all_unique_positions():
-            if not p.v.isDirty() and has_dirty_descendant(p):
-                p.v.setDirty(True)
+        dirtyvnodes = [v for v in c.fileCommands.gnxDict.values() if v.isDirty()]
+        def propagate(v):
+            for v1 in v.parents:
+                if not v1.isDirty():
+                    v1.setDirty(True)
+                    propagate(v1)
+        for v in dirtyvnodes:
+            propagate(v)
+
     #@+node:ekr.20150629072547.1: *4* find.preloadFindPattern
     def preloadFindPattern(self, w):
         '''Preload the find pattern from the selected text of widget w.'''