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.

     1

checkout

     2

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

     3

merge

     4

resolving manifests

     5

 overwrite None partial False

     6

 ancestor af1939970a1c local f26ec4fc3fa3+ remote 8e765a822af2

     7

  searching for copies back to rev 1

     8

  unmatched files in local:

     9

   c2

    10

  unmatched files in other:

    11

   b

    12

   b2

    13

  all copies found (* = to merge, ! = divergent):

    14

   c2 -> a2 

    15

   b -> a *

    16

   b2 -> a2 

    17

  checking for directory renames

    18

 a2: divergent renames -> dr

    19

 a: remote moved to b -> m

    20

 b2: remote created -> g

    21

copying a to b

    22

merging a and b

    23

my a@f26ec4fc3fa3+ other b@8e765a822af2 ancestor a@af1939970a1c

    24

removing a

    25

warning: detected divergent renames of a2 to:

    26

 c2

    27

 b2

    28

getting b2

    29

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

    30

(branch merge, don't forget to commit)

    31

M b

    32

  a

    33

M b2

    34

R a

    35

C c2

    36

blahblah

    37

   rev    offset  length   base linkrev nodeid       p1           p2

    38

     0         0      67      0       1 dc51707dfc98 000000000000 000000000000

    39

     1        67      72      1       3 b2494a44f0a9 000000000000 dc51707dfc98

    40

b renamed from a:dd03b83622e78778b403775d0d074b9ac7387a66