comparison mercurial/repoview.py @ 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

27916:9a09a9cfa503

                # cache is valid, so we can start reading the hidden revs
                data = fh.read()
                count = len(data) / 4
                hidden = frozenset(struct.unpack('>%ii' % count, data))
        return hidden
    finally:
        if fh:
            fh.close()

def computehidden(repo):

27917:97e0dc6d248c

                # cache is valid, so we can start reading the hidden revs
                data = fh.read()
                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()

def computehidden(repo):