bpo-40334: Correctly generate C parser when assigned var is None by isidentical · Pull Request #20296 · python/cpython

isidentical

When there are 2 negative lookaheads in a same rule, let's say
`!"(" blabla "," !")"`, there will the 2 `FunctionCall`'s where
assigned value is None. Currently when the `add_var` is called
the first one will be ignored (since it will be returned as same
from dedupe because there aren't any `None` named variables in
locals, but when the second lookahead's var is sent to dedupe it
will be returned as `None_1` and this wont be ignored by the
declaration generator in the `visit_Alt`. This patch adds an explicit
check to `add_var` to distinguish whether if there is a variable or not.

arturoescaip pushed a commit to arturoescaip/cpython that referenced this pull request

May 24, 2020

…honGH-20296)

When there are 2 negative lookaheads in the same rule, let's say `!"(" blabla "," !")"`, there will the 2 `FunctionCall`'s where assigned value is None. Currently when the `add_var` is called
the first one will be ignored but when the second lookahead's var is sent to dedupe it
will be returned as `None_1` and this won't be ignored by the declaration generator in the `visit_Alt`. This patch adds an explicit check to `add_var` to distinguish whether if there is a variable or not.