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

#!/bin/sh

     2

     3

hg init t

     4

cd t

     5

echo foo > a

     6

hg add a

     7

hg commit -m "1" -d "1000000 0"

     8

hg verify

     9

chmod -r .hg/store/data/a.i

    10

hg verify 2>/dev/null || echo verify failed

    11

chmod +r .hg/store/data/a.i

    12

hg verify 2>/dev/null || echo verify failed

    13

chmod -w .hg/store/data/a.i

    14

echo barber > a

    15

hg commit -m "2" -d "1000000 0" 2>/dev/null || echo commit failed

    16

chmod -w ../t

    17

hg diff --nodates