trunk: fix `'comments' in item` bug introduced in r7880, as `item` can be `None` depending on the diff options selected (the list of changes itself is not compacted in order to preserve the indexes used in links). Closes #8105.
trunk: fix `'comments' in item` bug introduced in r7880, as `item` can be `None` depending on the diff options selected (the list of changes itself is not compacted in order to preserve the indexes used in links). Closes #8105.


git-svn-id: f68c6b3b1dcd5d00a2560c384475aaef3bc99487@7933 af82e41b-90c4-0310-8c96-b1721e28e2e2

exocad/exotrac,dafrito/trac-mirror,exocad/exotrac,exocad/exotrac,exocad/exotrac,dafrito/trac-mirror,moreati/trac-gitsvn,moreati/trac-gitsvn,dafrito/trac-mirror,dokipen/trac,dokipen/trac,dokipen/trac,dafrito/trac-mirror,moreati/trac-gitsvn,moreati/trac-gitsvn