SimonSapin created this revision. Herald added a reviewer: hg-reviewers. Herald added a subscriber: mercurial-patches.
REVISION SUMMARY This code was meant to handle the case of a nodemap docket file pointing to a nodemap data file that doesn’t exist (anymore), but most likely caused an `UnboundLocalError` exception instead when `data` was used on the next line without being defined. This case is theoretically possible with a race condition between two hg processes, but is hard to reproduce or test: - Process A reads a docket file and finds a UID in it that points to a given data file name. - Process B decides that this same data file needs compacting. It writes a new one with a different UID, overwrites the docket file, then removes the old data file. - Only then process A tries to a open a file that doesn’t exist anymore. REPOSITORY rHG Mercurial BRANCH default REVISION DETAIL https://phab.mercurial-scm.org/D9533 AFFECTED FILES mercurial/revlogutils/nodemap.py CHANGE DETAILS diff --git a/mercurial/revlogutils/nodemap.py b/mercurial/revlogutils/nodemap.py --- a/mercurial/revlogutils/nodemap.py +++ b/mercurial/revlogutils/nodemap.py @@ -58,7 +58,9 @@ else: data = fd.read(data_length) except OSError as e: - if e.errno != errno.ENOENT: + if e.errno == errno.ENOENT: + return None + else: raise if len(data) < data_length: return None To: SimonSapin, #hg-reviewers Cc: mercurial-patches, mercurial-devel _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
