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.

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adding a

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1 files updated, 0 files merged, 0 files removed, 0 files unresolved

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1 files updated, 0 files merged, 0 files removed, 0 files unresolved

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1 files updated, 0 files merged, 0 files removed, 0 files unresolved

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% should fail because not at a head

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abort: repo has 3 heads - please merge with an explicit rev

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1 files updated, 0 files merged, 0 files removed, 0 files unresolved

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% should fail because > 2 heads

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abort: repo has 3 heads - please merge with an explicit rev

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% should succeed

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0 files updated, 0 files merged, 0 files removed, 0 files unresolved

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(branch merge, don't forget to commit)

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% should succeed - 2 heads

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0 files updated, 0 files merged, 0 files removed, 0 files unresolved

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(branch merge, don't forget to commit)

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% should fail because 1 head

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abort: there is nothing to merge - use "hg update" instead