changeset 27917:97e0dc6d248c stable

repoview: fix corrupted hiddencache crash Mercurial (issue5042) Before this patch if the hiddencache existed but was empty, it would crash mercurial. This patch adds exception handling when reading the hiddencache to avoid the issue. When encountering a corrupted cache file we print a devel warning. There would be no point in issuing a normal warning as the user wouldn't be able to do anything about the situation. The warning looks like: devel-warn: corrupted hidden cache, removing it at: /path/to/repoview.py
author Laurent Charignon <lcharignon@fb.com>
date Wed, 20 Jan 2016 13:43:01 -0800
parents 9a09a9cfa503
children c7cd551f07d0
files mercurial/repoview.py tests/test-obsolete.t
diffstat 2 files changed, 24 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/repoview.py	Wed Jan 20 13:40:59 2016 -0800
+++ b/mercurial/repoview.py	Wed Jan 20 13:43:01 2016 -0800
@@ -150,6 +150,13 @@
                 count = len(data) / 4
                 hidden = frozenset(struct.unpack('>%ii' % count, data))
         return hidden
+    except struct.error:
+        repo.ui.debug('corrupted hidden cache\n')
+        # No need to fix the content as it will get rewritten
+        return None
+    except (IOError, OSError):
+        repo.ui.debug('cannot read hidden cache\n')
+        return None
     finally:
         if fh:
             fh.close()
--- a/tests/test-obsolete.t	Wed Jan 20 13:40:59 2016 -0800
+++ b/tests/test-obsolete.t	Wed Jan 20 13:43:01 2016 -0800
@@ -951,6 +951,23 @@
   $ hg amendtransient
   [1, 3]
 
+Check that corrupted hidden cache does not crash
+
+  $ printf "" > .hg/cache/hidden
+  $ hg log -r . -T '{node}' --debug
+  corrupted hidden cache
+  8fd96dfc63e51ed5a8af1bec18eb4b19dbf83812 (no-eol)
+  $ hg log -r . -T '{node}' --debug
+  8fd96dfc63e51ed5a8af1bec18eb4b19dbf83812 (no-eol)
+
+Check that wrong hidden cache permission does not crash
+
+  $ chmod 000 .hg/cache/hidden
+  $ hg log -r . -T '{node}' --debug
+  cannot read hidden cache
+  error writing hidden changesets cache
+  8fd96dfc63e51ed5a8af1bec18eb4b19dbf83812 (no-eol)
+
 Test cache consistency for the visible filter
 1) We want to make sure that the cached filtered revs are invalidated when
 bookmarks change