revlog: add a fast path for "ambiguous identifier"
Before fd1bb7c, if the C index.partialmatch raises RevlogError, the Python
code raises "ambiguous identifier" error immediately, which is efficient.
fd1bb7c took hidden revisions into consideration and forced the slow path
enumerating the changelog to double-check hidden revisions. But it's not
necessary if we know the revlog has no hidden revisions.
This patch adds back the fast path for unfiltered revlogs.
# 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