matcher: fix issues regex flag contained in pattern (issue6759)...
matcher: fix issues regex flag contained in pattern (issue6759)
Python 3.11 is now enforcing that flag must be at the beginning of the regex
This creates a serious regression for people using Python 3.11 with an hgignore
using flag in a "relre" pattern.
We now detect any flags in such pattern and "prepend" our ".*" pattern after them.
In addition, we now insert the flag in the regexp to only affect the pattern we
are rewriting. Otherwise, the regex built from the combined pattern would these
flags in the middle of it anyway.
As a side effect of this last change, we fix a bug… before this change regex
flag in a pattern would affect all combined patterns. That was bad and is not
longer the case.
The Rust code needs to be updated to fix that very bug, but we will do it in
another changeset.
