view tests/test-empty-file.t @ 27464:c39ecb2b86b3

fileset: detect unintentional existing() invocation at runtime

A fileset predicate can invoke 'matchctx.existing()' successfully,
even if it isn't marked as "existing caller". It is aborted only in
some corner cases: e.g. there were one deleted file in the working
directory (see 8a0513bf030a for detail).

This patch makes 'matchctx.existing()' invocation abort if not
'_existingenabled', which is true only while "existing caller"
running.

After this changes, non-"existing caller" predicate function is
aborted immediately, whenever it invokes 'matchctx.existing()'. This
prevent developer from forgetting to mark a predicate as "existing
caller".

BTW, unintentional 'matchctx.status()' invocation can be detected
easily without any additional trick like this patch, because it
returns 'None' if a predicate isn't marked as "status caller", and
referring field (e.g. '.modified') of it is always aborted.

  $ 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 ..