patch.diff: restrict matcher to relative root in certain cases
Previously we'd request all results, then filter by relative root. This is
clearly inefficient, so we now restrict the matcher to the relative root for
certain easy cases.
The particular case here is when the matcher matches all files. In that case we
can simply create a matcher by the relative root.
This is purely an optimization and has no impact on correctness.
hg debuginstall
$ hg debuginstall
checking encoding (ascii)...
checking Python executable (*) (glob)
checking Python version (2.*) (glob)
checking Python lib (*lib*)... (glob)
checking installed modules (*mercurial)... (glob)
checking templates (*mercurial?templates)... (glob)
checking commit editor...
checking username...
no problems detected
hg debuginstall with no username
$ HGUSER= hg debuginstall
checking encoding (ascii)...
checking Python executable (*) (glob)
checking Python version (2.*) (glob)
checking Python lib (*lib*)... (glob)
checking installed modules (*mercurial)... (glob)
checking templates (*mercurial?templates)... (glob)
checking commit editor...
checking username...
no username supplied
(specify a username in your configuration file)
1 problems detected, please check your install!
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