view tests/test-empty-file.t @ 33284:b2670290eab4

followlines: join merge parents line ranges in blockdescendants() (issue5595)

In blockdescendants(), we had an assertion when line range of a merge
changeset was not consistent depending on which parent was considered for
computation. For instance, this might occur when file content (in lookup
range) is significantly different between parent branches of the merge as
demonstrated in added tests (where we almost completely rewrite the "baz" file
while also introducing similarities with its content in the other branch we
later merge to).

Now, in such case, we combine line ranges from all parents by storing the
envelope of both line ranges. This is conservative (the line range is
extended, possibly unnecessarily) but at least this should avoid missing
descendants with changes in a range that would fall in that of one parent but
not in another one (the case of "baz: narrow change (2->2+)" changeset in
tests).

  $ hg init a
  $ cd a
  $ touch empty1
  $ hg add empty1
  $ hg commit -m 'add empty1'

  $ touch empty2
  $ hg add empty2
  $ hg commit -m 'add empty2'

  $ hg up -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ touch empty3
  $ hg add empty3
  $ hg commit -m 'add empty3'
  created new head

  $ hg heads
  changeset:   2:a1cb177e0d44
  tag:         tip
  parent:      0:1e1d9c4e5b64
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add empty3
  
  changeset:   1:097d2b0e17f6
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add empty2
  

  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Before changeset 05257fd28591, we didn't notice the
empty file that came from rev 1:

  $ hg status
  M empty2
  $ hg commit -m merge
  $ hg manifest --debug tip
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty1
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty2
  b80de5d138758541c5f05265ad144ab9fa86d1db 644   empty3

  $ cd ..