revset: note case-sensitive match in grep stable

revset: note case-sensitive match in grep

--- a/mercurial/revset.py	Wed May 18 09:20:52 2011 +0200
+++ b/mercurial/revset.py	Wed May 18 09:28:11 2011 +0200
@@ -381,7 +381,8 @@
 def grep(repo, subset, x):
     """``grep(regex)``
     Like ``keyword(string)`` but accepts a regex. Use ``grep(r'...')``
-    to ensure special escape characters are handled correctly.
+    to ensure special escape characters are handled correctly. Unlike
+    ``keyword(string)``, the match is case-sensitive.
     """
     try:
         # i18n: "grep" is a keyword