[PATCH 1 of 1 v3] store: add names of successfully opened revlogs to fncache

[Mads Kiilerich]

# HG changeset patch
# User Mads Kiilerich <mads at kiilerich.com>
# Date 1335141331 -7200
# Branch stable
# Node ID dab6871ccc38b4c1748d67fa4ecf904c3b3018a1
# Parent  3440757d12850cfafa88a754b34f5d42e62e4c25
store: add names of successfully opened revlogs to fncache

fncache permanently drops the names of revlogs that can't be found when the
datastore iterator stats them, for example when verify walks over all revlogs.
The only way to re-add a removed revlog name to fncache was to open the revlog
for write.  Recovery (for example after restoring revlogs from a backup) was
thus quite hard.

This change makes fncache more like a cache by adding entries whenever a
missing revlog is opened.

Some operations open revlogs for reading without checking if they exist - they
will now heal fncache. Verify will thus be able to re-create entries that it
accidentially has removed. That will however only happen after it has
complained that the revlog is missing. Next time verify is run the problem is
gone.

diff --git a/mercurial/store.py b/mercurial/store.py
--- a/mercurial/store.py
+++ b/mercurial/store.py
@@ -372,9 +372,10 @@
         self.encode = encode
 
     def __call__(self, path, mode='r', *args, **kw):
-        if mode not in ('r', 'rb') and path.startswith('data/'):
+        opener = self.opener(self.encode(path), mode, *args, **kw)
+        if path.startswith('data/'):
             self.fncache.add(path)
-        return self.opener(self.encode(path), mode, *args, **kw)
+        return opener
 
 class fncachestore(basicstore):
     def __init__(self, path, openertype, encode):
diff --git a/tests/test-fncache.t b/tests/test-fncache.t
--- a/tests/test-fncache.t
+++ b/tests/test-fncache.t
@@ -55,6 +55,12 @@
   3 integrity errors encountered!
   (first damaged changeset appears to be 0)
   [1]
+  $ hg verify
+  checking changesets
+  checking manifests
+  crosschecking files in changesets and manifests
+  checking files
+  3 files, 3 changesets, 3 total revisions
   $ cd ..
 
 Non store repo:
diff --git a/tests/test-verify.t b/tests/test-verify.t
--- a/tests/test-verify.t
+++ b/tests/test-verify.t
@@ -90,6 +90,12 @@
   (first damaged changeset appears to be 0)
   [1]
   $ mv _q_u_i_c_k.txt.i .hg/store/data/
+  $ hg verify
+  checking changesets
+  checking manifests
+  crosschecking files in changesets and manifests
+  checking files
+  4 files, 1 changesets, 4 total revisions
 
 test revlog corruption