# HG changeset patch
# User Adrian Buehlmann <adrian@cadifra.com>
# Date 2010-03-03 13:50:35
# Node ID d5bd1beff794461611bb37999a79bd110c88d008
# Parent  7616ff5f3596d5630cd215debd67a50fb7e9cede

store: only add new entries to the fncache file

Newly added fncache entries were not added to the in-memory cache,
making it possible for 'hg convert' to cause duplicates in
.hg/store/fncache.

Duplicates in the fncache file are harmless, but excessive numbers
of duplicates from large converted repositories may slow down
execution speed considerably.

diff --git a/mercurial/store.py b/mercurial/store.py
--- a/mercurial/store.py
+++ b/mercurial/store.py
@@ -267,7 +267,9 @@ class fncache(object):
     def add(self, fn):
         if self.entries is None:
             self._load()
-        self.opener('fncache', 'ab').write(encodedir(fn) + '\n')
+        if fn not in self.entries:
+            self.opener('fncache', 'ab').write(encodedir(fn) + '\n')
+            self.entries.add(fn)
 
     def __contains__(self, fn):
         if self.entries is None:
@@ -290,9 +292,7 @@ class fncachestore(basicstore):
         self.fncache = fnc
 
         def fncacheopener(path, mode='r', *args, **kw):
-            if (mode not in ('r', 'rb')
-                and path.startswith('data/')
-                and path not in fnc):
+            if mode not in ('r', 'rb') and path.startswith('data/'):
                 fnc.add(path)
             return op(hybridencode(path), mode, *args, **kw)
         self.opener = fncacheopener
diff --git a/tests/test-convert b/tests/test-convert
--- a/tests/test-convert
+++ b/tests/test-convert
@@ -56,4 +56,10 @@ hg convert --source-type foo a a-foo
 echo % convert with imaginary sink type
 hg convert --dest-type foo a a-foo
 
+echo
+echo % "testing: convert must not produce duplicate entries in fncache"
+hg convert a b
+echo % "contents of fncache file:"
+cat b/.hg/store/fncache
+
 true
diff --git a/tests/test-convert.out b/tests/test-convert.out
--- a/tests/test-convert.out
+++ b/tests/test-convert.out
@@ -273,3 +273,17 @@ initializing destination a-foo repositor
 abort: foo: invalid source repository type
 % convert with imaginary sink type
 abort: foo: invalid destination repository type
+
+% testing: convert must not produce duplicate entries in fncache
+initializing destination b repository
+scanning source...
+sorting...
+converting...
+4 a
+3 b
+2 c
+1 d
+0 e
+% contents of fncache file:
+data/a.i
+data/b.i