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Stefan Fuhrmann closed SVN-4658. -------------------------------- Resolution: Fixed Fix Version/s: trunk Added a test in r1766590 and proposed backports to 1.9 and 1.8. > Can't reconstruct fulltext from DELTA against PLAIN in FSFS > ------------------------------------------------------------ > > Key: SVN-4658 > URL: https://issues.apache.org/jira/browse/SVN-4658 > Project: Subversion > Issue Type: Bug > Components: libsvn_fs_fs > Affects Versions: 1.9.4 > Environment: All > Reporter: Stefan Fuhrmann > Assignee: Stefan Fuhrmann > Fix For: trunk > > > A DELTA representation against a PLAIN delta base will not be > reconstructed correctly if > * it spans multiple txdelta windows (100kB), and > * there is a match against the base in one window W, and > * there has been no match against the base in the previous window W-1, > because the matching data is being taken from W-1 or earlier instead > of W. This causes an MD5 checksum mismatch and the data cannot be > read. > In repositories only written to by the Subversion libraries, i.e. no > third-party code, this issue is virtually restricted to properties and > directories after enabling their deltification in an existing repository. > The chances of the problem to actually manifest are small: > * Either, there must be node properties > 100kB that changed > so much that there is a 100kB that has no 64 byte match > with some earlier version of it. That would basically > limit this to non-textual properties. > * Or, there must be a directory with several 1000 entries > and each of these must have been touched, added or removed > over the last 512 revisions (max default delta span). > Or there were > 1000 entries added at or removed from the > beginning of the directory to shift the delta window > sufficiently. > The data is not being corrupted nor is there a known mechanism to corrupt > later commits due to this bug. A workaround is possible by re-instantiating > the previous version of the node: > * svn rm /url/of/unreadable/node > * svn cp /url/of/unreadable/node /url/of/unreadable/node@R-1 > or by disabling directory and / or property deltification. -- This message was sent by Atlassian JIRA (v6.3.4#6332)