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Release Notes

Read the CHANGES document included in the distribution for a more complete summary of changes to MHonArc. This document highlights important changes that have occurred and important usage details which you should be aware of before using MHonArc. If you are upgrading from a previous release, make sure to check for the highlighted incompatibilites from earlier releases.


Compatibility Notes

This sections provides notes dealing with compatibility issues if upgrading from a previous release of MHonArc:

UPGRADING FROM v2.4.x OR EARLIER: DEFRCNAME Change

The default value for the DEFRCNAME is now called ".mhonarc.mrc", or "mhonarc.mrc" under Windows and VMS. The old value was ".mhonarc.rc", or "mhonarc.rc". If you use the default resource file, you will need to rename the file to match the filenames used for v2.5 and later.

UPGRADING FROM v2.4.x OR EARLIER: HEADER and FOOTER Removed

The HEADER and FOOTER resources are no longer supported. If you are using these resources, the HEADER content and FOOTER content will be lost once v2.5, or later, of MHonArc processes an archive containing these resources.

The HEADER and FOOTER resources have been deprecated for a long time since they only applied to the main index; the thread index has no equivalent. The IDXPGBEGIN or LISTBEGIN resources can be used to achieve the same effect of HEADER. The IDXPGEND or LISTEND can be used to achieve the same effect of FOOTER.

UPGRADING FROM v2.4.x OR EARLIER: MIMEFILTERS API Change

The API for data filters registered via MIMEFILTERS is not capability with filters written for v2.4.x and earlier. See CHANGES and the documentation for the MIMEFILTERS resource for the API.

If you use custom style filters written for v2.4.x, or earlier, you will need to update them for them to work properly under v2.5, and later.

UPGRADING FROM v2.1.x OR EARLIER: Database Format Change

If you have archives created with v2.1.x, or earlier, the format of mime-related resources is not compatible with v2.2, and later, versions. MHonArc will reset the mime-related resources CHARSETCONVERTERS and MIMEFILTERS to their default values. MIMEARGS will also be reset to the default value unless you are upgrading to v2.5.8, or later, where the MIMEARGS settings will be preserved.

To avoid the resetting of the mime-related resource if you are using customized settings, you will need to re-specify your settings the next time you update an archive. If you always specify your resource settings each time you invoke MHonArc, then your settings should to still take effect.

You can also use the mha-dbedit program to apply your settings directly without processing the archive.

DOWNGRADING TO OLDER VERSIONS

Downgrading to an earlier version of MHonArc can be dangerous, especially if downgrading to an older version that used different storage formats in archive database files from the current version in use. If an older version of MHonArc is used to process an archive last updated by a new version, archive data can get lost and/or unexpected output can occur.

Changes in archive format are not common, so downgrading can be okay depending on the versions involved. The key versions to watch out for are the ones noted in this section where database format changes have occured. The following lists release numbers where a format change occured:

For example, if an archive was last updated with v2.5.0, processing the archive with a previous release will cause problems.

A possible method for successfully downgrading to a release with differences in the database format, is to try to reconstruct the database file using the mha-dbrecover utility contained in the MHonArc version the archive is being downgraded to.

Of course, the safest way to downgrade is to recreate an archive from the original raw mail data. It is good practice to preserve the raw mail data in some form for cases like these and for general archive recovering situations due to file corruption or other system failures.


General Notes


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$Date: 2002/06/27 05:00:01 $
MHonArc
Copyright © 1997-2001, Earl Hood, mhonarc@mhonarc.org