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

% new file

     2

applying patch from stdin

     3

% new empty file

     4

applying patch from stdin

     5

empty

     6

% chmod +x

     7

applying patch from stdin

     8

% copy

     9

applying patch from stdin

    10

a

    11

a

    12

% rename

    13

applying patch from stdin

    14

copyx

    15

empty

    16

new

    17

rename

    18

% delete

    19

applying patch from stdin

    20

empty

    21

new

    22

rename

    23

% regular diff

    24

applying patch from stdin

    25

% copy and modify

    26

applying patch from stdin

    27

a

    28

a

    29

b

    30

a

    31

a

    32

% rename and modify

    33

applying patch from stdin

    34

a

    35

a

    36

b

    37

c

    38

a

    39

% one file renamed multiple times

    40

applying patch from stdin

    41

9 rename2 rename3 rename3-2 / rename3 (rename2)rename3-2 (rename2)

    42

rename3

    43

rename3-2

    44

a

    45

a

    46

b

    47

c

    48

a

    49

    50

a

    51

a

    52

b

    53

c

    54

a

    55

% binary files and regular patch hunks

    56

applying patch from stdin

    57

foo

    58

045c85ba38952325e126c70962cc0f9d9077bc67 644 binary

    59

% many binary files

    60

applying patch from stdin

    61

045c85ba38952325e126c70962cc0f9d9077bc67 644 mbinary1

    62

a874b471193996e7cb034bb301cac7bdaf3e3f46 644 mbinary2

    63

% filenames with spaces

    64

applying patch from stdin

    65

foo