diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -11,6 +11,7 @@ import node as nodemod
 import bookmarks as bookmarksmod
 import match as matchmod
 from i18n import _
+import encoding
 
 elements = {
     "(": (20, ("group", 1, ")"), ("func", 1, ")")),
@@ -233,8 +234,8 @@ def author(repo, subset, x):
     Alias for ``user(string)``.
     """
     # i18n: "author" is a keyword
-    n = getstring(x, _("author requires a string")).lower()
-    return [r for r in subset if n in repo[r].user().lower()]
+    n = encoding.lower(getstring(x, _("author requires a string")))
+    return [r for r in subset if n in encoding.lower(repo[r].user())]
 
 def bisect(repo, subset, x):
     """``bisect(string)``
@@ -376,11 +377,11 @@ def desc(repo, subset, x):
     Search commit message for string. The match is case-insensitive.
     """
     # i18n: "desc" is a keyword
-    ds = getstring(x, _("desc requires a string")).lower()
+    ds = encoding.lower(getstring(x, _("desc requires a string")))
     l = []
     for r in subset:
         c = repo[r]
-        if ds in c.description().lower():
+        if ds in encoding.lower(c.description()):
             l.append(r)
     return l
 
@@ -522,12 +523,12 @@ def keyword(repo, subset, x):
     string. The match is case-insensitive.
     """
     # i18n: "keyword" is a keyword
-    kw = getstring(x, _("keyword requires a string")).lower()
+    kw = encoding.lower(getstring(x, _("keyword requires a string")))
     l = []
     for r in subset:
         c = repo[r]
         t = " ".join(c.files() + [c.user(), c.description()])
-        if kw in t.lower():
+        if kw in encoding.lower(t):
             l.append(r)
     return l
 
diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -475,3 +475,61 @@ issue2549 - correct optimizations
   $ log 'max(1 or 2) and not 2'
   $ log 'min(1 or 2) and not 1'
   $ log 'last(1 or 2, 1) and not 2'
+
+  $ cd ..
+
+test author/desc/keyword in problematic encoding
+# unicode: cp932:
+# u30A2    0x83 0x41(= 'A')
+# u30C2    0x83 0x61(= 'a')
+
+  $ hg init problematicencoding
+  $ cd problematicencoding
+
+  $ python > setup.sh <<EOF
+  > print u'''
+  > echo a > text
+  > hg add text
+  > hg --encoding utf-8 commit -u '\u30A2' -m none
+  > echo b > text
+  > hg --encoding utf-8 commit -u '\u30C2' -m none
+  > echo c > text
+  > hg --encoding utf-8 commit -u none -m '\u30A2'
+  > echo d > text
+  > hg --encoding utf-8 commit -u none -m '\u30C2'
+  > '''.encode('utf-8')
+  > EOF
+  $ sh < setup.sh
+
+test in problematic encoding
+  $ python > test.sh <<EOF
+  > print u'''
+  > hg --encoding cp932 log --template '{rev}\\n' -r 'author(\u30A2)'
+  > echo ====
+  > hg --encoding cp932 log --template '{rev}\\n' -r 'author(\u30C2)'
+  > echo ====
+  > hg --encoding cp932 log --template '{rev}\\n' -r 'desc(\u30A2)'
+  > echo ====
+  > hg --encoding cp932 log --template '{rev}\\n' -r 'desc(\u30C2)'
+  > echo ====
+  > hg --encoding cp932 log --template '{rev}\\n' -r 'keyword(\u30A2)'
+  > echo ====
+  > hg --encoding cp932 log --template '{rev}\\n' -r 'keyword(\u30C2)'
+  > '''.encode('cp932')
+  > EOF
+  $ sh < test.sh
+  0
+  ====
+  1
+  ====
+  2
+  ====
+  3
+  ====
+  0
+  2
+  ====
+  1
+  3
+
+  $ cd ..