hidden: use both parents of working directory

If we are merging with and extinct revision, this extinct revision should not be
hidden.

mercurial/repoview.py

@@ -18,7 +18,7 b' def computehidden(repo):'
     assert not repo.changelog.filteredrevs
     if repo.obsstore:
         ### hide extinct changeset that are not accessible by any mean
-        hiddenquery = 'extinct() - ::(. + bookmark())'
+        hiddenquery = 'extinct() - ::(parents() + bookmark())'
         return frozenset(repo.revs(hiddenquery))
     return frozenset()
 

tests/test-log.t

@@ -1162,6 +1162,20 b' enable obsolete to test hidden feature'
   1:a765632148dc55d38c35c4f247c618701886cb2f
   0:9f758d63dcde62d547ebfb08e1e7ee96535f2b05
 
+test that parent prevent a changeset to be hidden
+
+  $ hg up 1 -q
+  $ hg log --template='{rev}:{node}\n'
+  1:a765632148dc55d38c35c4f247c618701886cb2f
+  0:9f758d63dcde62d547ebfb08e1e7ee96535f2b05
+
+test that second parent prevent a changeset to be hidden too
+
+  $ hg debugsetparents 0 1 # nothing suitable to merge here
+  $ hg log --template='{rev}:{node}\n'
+  1:a765632148dc55d38c35c4f247c618701886cb2f
+  0:9f758d63dcde62d547ebfb08e1e7ee96535f2b05
+
 clear extensions configuration
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "obs=!" >> $HGRCPATH