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.

#!/bin/sh

hg init a
cd a
touch empty1
hg add empty1
hg commit -m 'add empty1' -d '1000000 0'

touch empty2
hg add empty2
hg commit -m 'add empty2' -d '1000000 0'

hg up -C 0
touch empty3
hg add empty3
hg commit -m 'add empty3' -d '1000000 0'

hg heads

hg merge 1
# before changeset 05257fd28591, we didn't notice the 
# empty file that came from rev 1.
hg status
hg commit -m merge -d '1000000 0'
hg manifest --debug tip