[PATCH 1 of 3 V2] revset: stop lowercasing the regex pattern for 'author'

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1484192530 18000
#      Wed Jan 11 22:42:10 2017 -0500
# Node ID bdbffc45e32a206ffca59ee9664feabab795aef4
# Parent  f8d510b7f4bac4bbf519f098a4ca70e54165c960
revset: stop lowercasing the regex pattern for 'author'

It was probably unintentional for regex, as the meaning of some sequences like
\S and \s is actually inverted by changing the case.  For backward compatibility
however, the matching is forced to case insensitive.

diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -556,9 +556,9 @@
     """Alias for ``user(string)``.
     """
     # i18n: "author" is a keyword
-    n = encoding.lower(getstring(x, _("author requires a string")))
-    kind, pattern, matcher = _substringmatcher(n)
-    return subset.filter(lambda x: matcher(encoding.lower(repo[x].user())),
+    n = getstring(x, _("author requires a string"))
+    kind, pattern, matcher = _substringmatcher(n, casesensitive=False)
+    return subset.filter(lambda x: matcher(repo[x].user()),
                          condrepr=('<user %r>', n))
 
 @predicate('bisect(string)', safe=True)
@@ -2246,10 +2246,15 @@
 
     return subset.filter(matches, condrepr=('<subrepo %r>', pat))
 
-def _substringmatcher(pattern):
-    kind, pattern, matcher = util.stringmatcher(pattern)
+def _substringmatcher(pattern, casesensitive=True):
+    kind, pattern, matcher = util.stringmatcher(pattern,
+                                                casesensitive=casesensitive)
     if kind == 'literal':
-        matcher = lambda s: pattern in s
+        if not casesensitive:
+            pattern = encoding.lower(pattern)
+            matcher = lambda s: pattern in encoding.lower(s)
+        else:
+            matcher = lambda s: pattern in s
     return kind, pattern, matcher
 
 @predicate('tag([name])', safe=True)
diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -865,6 +865,17 @@
   7
   8
   9
+  $ log 'author(r"re:\S")'
+  0
+  1
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
   $ log 'branch(é)'
   8
   9