comparison tests/test-revset.t @ 25996:b12e00a05d57 stable

revset: prevent crash caused by empty group expression while optimizing "or"

An empty group expression "()" generates None in AST, so it should be tested
before destructuring a tuple.

"A | ()" is still evaluated to an error because I'm not sure whether "()"
represents an empty set or an empty expression (= a unit value). They are
identical in "or" operation, but they should be evaluated differently in
"and" operation.

  expression  empty set  unit value
  ----------  ---------  ----------
  ()          {}         A
  A & ()      {}         A
  A | ()      A          A

25995:4f703dcc626f

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test that chained `or` operations never eat up stack (issue4624)
(uses `0:1` instead of `0` to avoid future optimization of trivial revisions)

  $ hg log -T '{rev}\n' -r "`python -c "print '|'.join(['0:1'] * 500)"`"
  0

25996:b12e00a05d57

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no crash by empty group "()" while optimizing `or` operations

  $ try --optimize '0|()'
  (or
    ('symbol', '0')
    (group
      None))
  * optimized:
  (or
    ('symbol', '0')
    None)
  hg: parse error: missing argument
  [255]

test that chained `or` operations never eat up stack (issue4624)
(uses `0:1` instead of `0` to avoid future optimization of trivial revisions)

  $ hg log -T '{rev}\n' -r "`python -c "print '|'.join(['0:1'] * 500)"`"
  0