Avoid extra filelogs entries. Right now, there are some situations in which localrepo.filecommit can create filelog entries even though they're not needed. For example: - permissions for a file have changed; - qrefresh can create a filelog entry identical to its parent (see the added test); - convert-repo creates extra filelog entries in every merge where the first parent has added files (for example, changeset ebebe9577a1a of the kernel repo added extra filelog entries to files in the arch/blackfin directory, even though the merge should only touch the drivers/ata directory). This makes "hg log file" in a converted repo less useful than it could be, since it may mention many merges that don't actually touch that specific file. They all come from the same basic problem: localrepo.commit (through filecommit) creates new filelog entries for all files passed to it (except for some cases during a merge). Patch and test case provided by Benoit. This should fix issue351.

reverting a
changeset 3:107ce1ee2b43 backs out changeset 1:25a1420a55f8
merging with changeset 2:e6c3abc120e7
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
abort: invalid date: 'should fail' 
transaction abort!
rollback completed
abort: date exceeds 32 bits: 100000000000000000
transaction abort!
rollback completed
abort: impossible time zone offset: 1400000
transaction abort!
rollback completed
Sun Jan 15 13:30:00 2006 +0500
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Sat Apr 15 13:30:00 2006 +0200
Sat Apr 15 13:30:00 2006 +0000
Wed Feb 01 13:00:30 2006 -0500
Wed Feb 01 13:00:30 2006 +0000