diff --git a/mercurial/encoding.py b/mercurial/encoding.py
--- a/mercurial/encoding.py
+++ b/mercurial/encoding.py
@@ -87,11 +87,17 @@ def fromlocal(s):
     except LookupError, k:
         raise error.Abort("%s, please check your locale settings" % k)
 
+# How to treat ambiguous-width characters. Set to 'wide' to treat as wide.
+ambiguous = os.environ.get("HGENCODINGAMBIGUOUS", "narrow")
+
 def colwidth(s):
     "Find the column width of a UTF-8 string for display"
     d = s.decode(encoding, 'replace')
     if hasattr(unicodedata, 'east_asian_width'):
+        wide = "WF"
+        if ambiguous == "wide":
+            wide = "WFA"
         w = unicodedata.east_asian_width
-        return sum([w(c) in 'WFA' and 2 or 1 for c in d])
+        return sum([w(c) in wide and 2 or 1 for c in d])
     return len(d)
 
diff --git a/mercurial/help/environment.txt b/mercurial/help/environment.txt
--- a/mercurial/help/environment.txt
+++ b/mercurial/help/environment.txt
@@ -24,6 +24,13 @@ HGENCODINGMODE
     "ignore", which drops them. This setting can be overridden with
     the --encodingmode command-line option.
 
+HGENCODINGAMBIGUOUS
+    This sets Mercurial's behavior for handling characters with
+    "ambiguous" widths like accented Latin characters with East Asian
+    fonts. By default, Mercurial assumes ambiguous characters are
+    narrow, set this variable to "wide" if such characters cause
+    formatting problems.
+
 HGMERGE
     An executable to use for resolving merge conflicts. The program
     will be executed with three arguments: local file, remote file,
diff --git a/tests/test-encoding.t b/tests/test-encoding.t
--- a/tests/test-encoding.t
+++ b/tests/test-encoding.t
@@ -166,13 +166,13 @@ hg tags (latin-1)
 
   $ HGENCODING=latin-1 hg tags
   tip                                5:093c6077d1c8
-  é                                 3:ca661e7520de
+  é                                  3:ca661e7520de
 
 hg tags (utf-8)
 
   $ HGENCODING=utf-8 hg tags
   tip                                5:093c6077d1c8
-  é                                 3:ca661e7520de
+  é                                  3:ca661e7520de
 
 hg branches (ascii)
 
@@ -183,13 +183,13 @@ hg branches (ascii)
 hg branches (latin-1)
 
   $ HGENCODING=latin-1 hg branches
-  é                             5:093c6077d1c8
+  é                              5:093c6077d1c8
   default                        4:94db611b4196 (inactive)
 
 hg branches (utf-8)
 
   $ HGENCODING=utf-8 hg branches
-  é                             5:093c6077d1c8
+  é                              5:093c6077d1c8
   default                        4:94db611b4196 (inactive)
   $ echo '[ui]' >> .hg/hgrc
   $ echo 'fallbackencoding = koi8-r' >> .hg/hgrc