view tests/test-issue1877.t @ 42193:14589f1989e9 stable

context: check file exists before getting data from _wrappedctx

overlayworkingctx class is used to do in-memory merging. The data() function of
that class has logic to look for data() in the wrappedctx if the file data in
cache is empty and if the file is dirty. This assumes that if a file is dirty
and cache has empty data for it, it will exists in the _wrappedctx.

However this assumption can be False in case when we are merging a file which is
empty in destination. In these cases, the backup file 'foo.orig' created by our
internal merge algorithms will be empty, however it won't be present in
_wrappedctx. This case will lead us to error like the one this patch is fixing.

Let's only fallback to getting data from wrappedctx if cache has 'None' as data.

Differential Revision: https://phab.mercurial-scm.org/D6308

https://bz.mercurial-scm.org/1877

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg add a
  $ hg ci -m 'a'
  $ echo b > a
  $ hg ci -m'b'
  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg book main
  $ hg book
   * main                      0:cb9a9f314b8b
  $ echo c > c
  $ hg add c
  $ hg ci -m'c'
  created new head
  $ hg book
   * main                      2:d36c0562f908
  $ hg heads
  changeset:   2:d36c0562f908
  bookmark:    main
  tag:         tip
  parent:      0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     c
  
  changeset:   1:1e6c11564562
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     b
  
  $ hg up 1e6c11564562
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (leaving bookmark main)
  $ hg merge main
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg book
     main                      2:d36c0562f908
  $ hg ci -m'merge'
  $ hg book
     main                      2:d36c0562f908

  $ cd ..