# HG changeset patch
# User Martin von Zweigbergk <martinvonz@google.com>
# Date 2017-05-28 06:05:10
# Node ID 2af0b9a02bf99a52e8f6ec8fd2dce1268bcce24a
# Parent  c777dac2b27ccda26134d8efeef7eef37bb80595

hidden: make _revealancestors() reveal ancestors exclusively

I think this seems more expected. It also prepares for the next
commit.

diff --git a/mercurial/repoview.py b/mercurial/repoview.py
--- a/mercurial/repoview.py
+++ b/mercurial/repoview.py
@@ -53,11 +53,10 @@ def _revealancestors(pfunc, hidden, revs
     - hidden: the (preliminary) hidden revisions, to be updated
     - revs: iterable of revnum,
 
-    (Ancestors are revealed inclusively, i.e. the elements in 'revs' are
-    also revealed)
+    (Ancestors are revealed exclusively, i.e. the elements in 'revs' are
+    *not* revealed)
     """
     stack = list(revs)
-    hidden -= set(stack)
     while stack:
         for p in pfunc(stack.pop()):
             if p != nullrev and p in hidden:
@@ -79,8 +78,7 @@ def computehidden(repo):
         visible = set(mutable - hidden)
         visible |= (hidden & pinnedrevs(repo))
         if visible:
-            # don't modify possibly cached result of hideablerevs()
-            hidden = hidden.copy()
+            hidden = hidden - visible
             _revealancestors(pfunc, hidden, visible)
     return frozenset(hidden)