hidden: unify the static and dynamic blocker logic

hidden: unify the static and dynamic blocker logic

We no longer have cache and they both work the same way. Unifying the logic
simplify the code and reduce the amount of set copies.

--- a/mercurial/repoview.py	Sun May 21 15:53:08 2017 +0200
+++ b/mercurial/repoview.py	Sun May 21 15:47:06 2017 +0200
@@ -47,30 +47,6 @@
         blockers.update(rev(t[0]) for t in tags.values() if t[0] in nodemap)
     return blockers
 
-def _getstatichidden(repo):
-    """Revision to be hidden (disregarding dynamic blocker)
-
-    To keep a consistent graph, we cannot hide any revisions with
-    non-hidden descendants. This function computes the set of
-    revisions that could be hidden while keeping the graph consistent.
-
-    A second pass will be done to apply "dynamic blocker" like bookmarks or
-    working directory parents.
-
-    """
-    assert not repo.changelog.filteredrevs
-    hidden = hideablerevs(repo)
-    if hidden:
-        pfunc = repo.changelog.parentrevs
-
-        mutablephases = (phases.draft, phases.secret)
-        mutable = repo._phasecache.getrevset(repo, mutablephases)
-        blockers = _consistencyblocker(pfunc, hidden, mutable)
-
-        if blockers:
-            hidden = hidden - _domainancestors(pfunc, blockers, mutable)
-    return hidden
-
 def _consistencyblocker(pfunc, hideable, domain):
     """return non-hideable changeset blocking hideable one
 
@@ -129,21 +105,20 @@
     During most operation hidden should be filtered."""
     assert not repo.changelog.filteredrevs
 
-    hidden = frozenset()
-    hideable = hideablerevs(repo)
-    if hideable:
-        cl = repo.changelog
-        hidden = frozenset(_getstatichidden(repo))
+    hidden = hideablerevs(repo)
+    if hidden:
+        pfunc = repo.changelog.parentrevs
+        mutablephases = (phases.draft, phases.secret)
+        mutable = repo._phasecache.getrevset(repo, mutablephases)
+
+        blockers = _consistencyblocker(pfunc, hidden, mutable)
 
         # check if we have wd parents, bookmarks or tags pointing to hidden
         # changesets and remove those.
-        dynamic = hidden & revealedrevs(repo)
-        if dynamic:
-            pfunc = cl.parentrevs
-            mutablephases = (phases.draft, phases.secret)
-            mutable = repo._phasecache.getrevset(repo, mutablephases)
-            hidden = hidden - _domainancestors(pfunc, dynamic, mutable)
-    return hidden
+        blockers |= (hidden & revealedrevs(repo))
+        if blockers:
+            hidden = hidden - _domainancestors(pfunc, blockers, mutable)
+    return frozenset(hidden)
 
 def computeunserved(repo):
     """compute the set of revision that should be filtered when used a server