revlog: fix _cache usage in revision()
As documented at revlog.__init__, revlog._cache stores raw text.
The current read and write usage of "_cache" in revlog.revision lacks of
raw=True check.
This patch fixes that by adding check about raw, and storing rawtext
explicitly in _cache.
Note: it may slow down cache hit code path when raw=False and flags=0. That
performance issue will be fixed in a later patch.
test-revlog-raw now points us to a new problem.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true