convert: add a mode where mercurial_sink skips empty revisions. The getchanges function of some converter_source classes can return some false positives. I.e. they sometimes claim that a file "foo" was changed in some revision, even though its contents are still the same. convert_svn is particularly bad, but I think this can also happen with convert_cvs and, at least in theory, with mercurial_source. For regular conversions this is not really a problem - as long as getfile returns the right contents, we'll get a converted revision with the right contents. But when we use --filemap, this could lead to superfluous revisions being converted. Instead of fixing every converter_source, I decided to change mercurial_sink to work around this problem. When --filemap is used, we're interested only in revisions that touch some specific files. If a revision doesn't change any of these files, then we're not interested in it (at least for revisions with a single parent; merges are special). For mercurial_sink, we abuse this property and rollback a commit if the manifest text hasn't changed. This avoids duplicating the logic from localrepo.filecommit to detect unchanged files.

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adding bar

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adding foo

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

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% start imerge

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1 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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U foo

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foo

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bar

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bar

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bar

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% status -v

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merging e6da46716401 and 30d266f502e7

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U foo (foo2)

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% next

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foo

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% merge next

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merging foo and foo2

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all conflicts resolved

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% unresolve

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% merge foo

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merging foo and foo2

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all conflicts resolved

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% save

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% load

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

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2 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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(branch merge, don't forget to commit)

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R foo

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all conflicts resolved

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foo

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changeset:   3:fa9a6defdcaf

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tag:         tip

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parent:      2:e6da46716401

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parent:      1:30d266f502e7

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user:        test

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date:        Thu Jan 01 00:00:03 1970 +0000

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files:       foo foo2

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description:

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merged

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% nothing to merge -- tip

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abort: there is nothing to merge

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

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% nothing to merge

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