highlight: fixes garbled text in non-UTF-8 environment

This patch treats all files inside repository as encoded by
locale's encoding when pygmentize.

We can assume that most files are written in locale's encoding,
but current implementation treats them as UTF-8.
So there's no way to specify the encoding of files.

Current implementation, db7557359636 (issue1341):
1. Convert original `text`, which is treated as UTF-8, to locale's encoding.
   `encoding.tolocal()` is the method to convert from internal UTF-8 to local.
   If original `text` is not UTF-8, e.g. Japanese EUC-JP, some characters
   become garbled here.
2. pygmentize, with no UnicodeDecodeError.

This patch:
1. Convert original `text`, which is treated as locale's encoding, to unicode.
   Pygments prefers unicode object than raw str. [1]_
   If original `text` is not encoded by locale's encoding, some characters
   become garbled here.
2. pygmentize, also with no UnicodeDecodeError :)
3. Convert unicode back to raw str, which is encoded by locale's.

.. [1] http://pygments.org/docs/unicode/

hgext/highlight/highlight.py

@@ -32,26 +32,27 b' def pygmentize(field, fctx, style, tmpl)'
     if util.binary(text):
         return
 
-    # avoid UnicodeDecodeError in pygments
-    text = encoding.tolocal(text)
+    # Pygments is best used with Unicode strings:
+    # <http://pygments.org/docs/unicode/>
+    text = text.decode(encoding.encoding, 'replace')
 
     # To get multi-line strings right, we can't format line-by-line
     try:
-        lexer = guess_lexer_for_filename(fctx.path(), text[:1024],
-                                         encoding=encoding.encoding)
+        lexer = guess_lexer_for_filename(fctx.path(), text[:1024])
     except (ClassNotFound, ValueError):
         try:
-            lexer = guess_lexer(text[:1024], encoding=encoding.encoding)
+            lexer = guess_lexer(text[:1024])
         except (ClassNotFound, ValueError):
-            lexer = TextLexer(encoding=encoding.encoding)
+            lexer = TextLexer()
 
-    formatter = HtmlFormatter(style=style, encoding=encoding.encoding)
+    formatter = HtmlFormatter(style=style)
 
     colorized = highlight(text, lexer, formatter)
     # strip wrapping div
     colorized = colorized[:colorized.find('\n</pre>')]
     colorized = colorized[colorized.find('<pre>')+5:]
-    coloriter = iter(colorized.splitlines())
+    coloriter = (s.encode(encoding.encoding, 'replace')
+                 for s in colorized.splitlines())
 
     tmpl.filters['colorize'] = lambda x: coloriter.next()
 

tests/test-highlight

@@ -121,3 +121,28 b' rm out'
 
 echo % errors encountered
 cat errors.log
+
+cd ..
+hg init eucjp
+cd eucjp
+
+printf '\265\376\n' >> eucjp.txt  # Japanese kanji "Kyo"
+
+hg ci -Ama
+
+hgserveget () {
+    "$TESTDIR/killdaemons.py"
+    echo % HGENCODING="$1" hg serve
+    HGENCODING="$1" hg serve -p $HGPORT -d -n test --pid-file=hg.pid -E errors.log
+    cat hg.pid >> $DAEMON_PIDS
+
+    echo % hgweb filerevision, html
+    "$TESTDIR/get-with-headers.py" localhost:$HGPORT "/file/tip/$2" \
+        | grep '<div class="parity0 source">' | $TESTDIR/printrepr.py
+    echo % errors encountered
+    cat errors.log
+}
+
+hgserveget euc-jp eucjp.txt
+hgserveget utf-8 eucjp.txt
+hgserveget us-ascii eucjp.txt

tests/test-highlight.out

@@ -538,3 +538,16 b' 200 Script output follows'
 /* pygments_style = fruity */
 
 % errors encountered
+adding eucjp.txt
+% HGENCODING=euc-jp hg serve
+% hgweb filerevision, html
+<div class="parity0 source"><a href="#l1" id="l1">     1</a> \xb5\xfe</div>
+% errors encountered
+% HGENCODING=utf-8 hg serve
+% hgweb filerevision, html
+<div class="parity0 source"><a href="#l1" id="l1">     1</a> \xef\xbf\xbd\xef\xbf\xbd</div>
+% errors encountered
+% HGENCODING=us-ascii hg serve
+% hgweb filerevision, html
+<div class="parity0 source"><a href="#l1" id="l1">     1</a> ??</div>
+% errors encountered