[tor-commits] [tor/maint-0.2.2] Unmap microdesc cache before replacing it.

[nickm at torproject.org]

commit bdff7e3299d78cd2f7aa4a31e5f57c1aeef5ffa1
Author: Nick Mathewson <nickm at torproject.org>
Date:   Thu May 12 11:19:52 2011 -0400

    Unmap microdesc cache before replacing it.
    
    If we do a replace-then-munmap, windows will never actually rewrite
    the microdesc cache.
    
    Found by wanoskarnet; bugfix on 0.2.2.6-alpha.
---
 changes/md_cache_replace |    6 ++++++
 src/or/microdesc.c       |    5 +++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/changes/md_cache_replace b/changes/md_cache_replace
new file mode 100644
index 0000000..88e029c
--- /dev/null
+++ b/changes/md_cache_replace
@@ -0,0 +1,6 @@
+  o Minor bugfixes
+    - Avoid a bug that would keep us from replacing a microdescriptor
+      cache on Windows.  (We would try to replace the file while still
+      holding it open.  That's fine on Unix, but Windows doesn't let us
+      do that.)  Bugfix on 0.2.2.6-alpha; bug found by wanoskarnet.
+
diff --git a/src/or/microdesc.c b/src/or/microdesc.c
index 5740c40..1554aca 100644
--- a/src/or/microdesc.c
+++ b/src/or/microdesc.c
@@ -399,10 +399,11 @@ microdesc_cache_rebuild(microdesc_cache_t *cache, int force)
     smartlist_add(wrote, md);
   }
 
-  finish_writing_to_file(open_file); /*XXX Check me.*/
-
   if (cache->cache_content)
     tor_munmap_file(cache->cache_content);
+
+  finish_writing_to_file(open_file); /*XXX Check me.*/
+
   cache->cache_content = tor_mmap_file(cache->cache_fname);
 
   if (!cache->cache_content && smartlist_len(wrote)) {