Mercurial > hg
view mercurial/encoding.py @ 25708:d3d32643c060
wireproto: correctly escape batched args and responses (issue4739)
This issue appears to be as old as wireproto batching itself: I can
reproduce the failure as far back as 08ef6b5f3715 trivially by
rebasing the test changes in this patch, which was back in the 1.9
era. I didn't test before that change, because prior to that the
testfile has a different name and I'm lazy.
Note that the test thought it was checking this case, but it actually
wasn't: it put a literal ; in the arg and response for its greet
command, but the mangle/unmangle step defined in the test meant that
instead of "Fo, =;o" going over the wire, "Gp-!><p" went instead,
which doesn't contain any special characters (those being [.=;]) and
thus not exercising the escaping. The test has been updated to use
pre-unmangled special characters, so the request is now "Fo+<:o",
which mangles to "Gp,=;p". I have confirmed that the test fails
without the adjustment to the escaping rules in wireproto.py.
No existing clients of RPC batching were depending on the old behavior
in any way. The only *actual* users of batchable RPCs in core were:
1) largefiles, wherein it batches up many statlfile calls. It sends
hexlified hashes over the wire and gets a 0, 1, or 2 back as a
response. No risk of special characters.
2) setdiscovery, which was using heads() and known(), both of which
communicate via hexlified nodes. Again, no risk of special characters.
Since the escaping functionality has been completely broken since it
was introduced, we know that it has no users. As such, we can change
the escaping mechanism without having to worry about backwards
compatibility issues.
For the curious, this was detected by chance: it happens that the
lz4-compressed text of a test file for remotefilelog compressed to
something containing a ;, which then caused the failure when I moved
remotefilelog to using batching for file content fetching.
author | Augie Fackler <augie@google.com> |
---|---|
date | Tue, 30 Jun 2015 19:19:17 -0400 |
parents | 328739ea70c3 |
children | cf47bdb2183c |
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# encoding.py - character transcoding support for Mercurial # # Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. import error import unicodedata, locale, os # These unicode characters are ignored by HFS+ (Apple Technote 1150, # "Unicode Subtleties"), so we need to ignore them in some places for # sanity. _ignore = [unichr(int(x, 16)).encode("utf-8") for x in "200c 200d 200e 200f 202a 202b 202c 202d 202e " "206a 206b 206c 206d 206e 206f feff".split()] # verify the next function will work assert set([i[0] for i in _ignore]) == set(["\xe2", "\xef"]) def hfsignoreclean(s): """Remove codepoints ignored by HFS+ from s. >>> hfsignoreclean(u'.h\u200cg'.encode('utf-8')) '.hg' >>> hfsignoreclean(u'.h\ufeffg'.encode('utf-8')) '.hg' """ if "\xe2" in s or "\xef" in s: for c in _ignore: s = s.replace(c, '') return s def _getpreferredencoding(): ''' On darwin, getpreferredencoding ignores the locale environment and always returns mac-roman. http://bugs.python.org/issue6202 fixes this for Python 2.7 and up. This is the same corrected code for earlier Python versions. However, we can't use a version check for this method, as some distributions patch Python to fix this. Instead, we use it as a 'fixer' for the mac-roman encoding, as it is unlikely that this encoding is the actually expected. ''' try: locale.CODESET except AttributeError: # Fall back to parsing environment variables :-( return locale.getdefaultlocale()[1] oldloc = locale.setlocale(locale.LC_CTYPE) locale.setlocale(locale.LC_CTYPE, "") result = locale.nl_langinfo(locale.CODESET) locale.setlocale(locale.LC_CTYPE, oldloc) return result _encodingfixers = { '646': lambda: 'ascii', 'ANSI_X3.4-1968': lambda: 'ascii', 'mac-roman': _getpreferredencoding } try: encoding = os.environ.get("HGENCODING") if not encoding: encoding = locale.getpreferredencoding() or 'ascii' encoding = _encodingfixers.get(encoding, lambda: encoding)() except locale.Error: encoding = 'ascii' encodingmode = os.environ.get("HGENCODINGMODE", "strict") fallbackencoding = 'ISO-8859-1' class localstr(str): '''This class allows strings that are unmodified to be round-tripped to the local encoding and back''' def __new__(cls, u, l): s = str.__new__(cls, l) s._utf8 = u return s def __hash__(self): return hash(self._utf8) # avoid collisions in local string space def tolocal(s): """ Convert a string from internal UTF-8 to local encoding All internal strings should be UTF-8 but some repos before the implementation of locale support may contain latin1 or possibly other character sets. We attempt to decode everything strictly using UTF-8, then Latin-1, and failing that, we use UTF-8 and replace unknown characters. The localstr class is used to cache the known UTF-8 encoding of strings next to their local representation to allow lossless round-trip conversion back to UTF-8. >>> u = 'foo: \\xc3\\xa4' # utf-8 >>> l = tolocal(u) >>> l 'foo: ?' >>> fromlocal(l) 'foo: \\xc3\\xa4' >>> u2 = 'foo: \\xc3\\xa1' >>> d = { l: 1, tolocal(u2): 2 } >>> len(d) # no collision 2 >>> 'foo: ?' in d False >>> l1 = 'foo: \\xe4' # historical latin1 fallback >>> l = tolocal(l1) >>> l 'foo: ?' >>> fromlocal(l) # magically in utf-8 'foo: \\xc3\\xa4' """ try: try: # make sure string is actually stored in UTF-8 u = s.decode('UTF-8') if encoding == 'UTF-8': # fast path return s r = u.encode(encoding, "replace") if u == r.decode(encoding): # r is a safe, non-lossy encoding of s return r return localstr(s, r) except UnicodeDecodeError: # we should only get here if we're looking at an ancient changeset try: u = s.decode(fallbackencoding) r = u.encode(encoding, "replace") if u == r.decode(encoding): # r is a safe, non-lossy encoding of s return r return localstr(u.encode('UTF-8'), r) except UnicodeDecodeError: u = s.decode("utf-8", "replace") # last ditch return u.encode(encoding, "replace") # can't round-trip except LookupError as k: raise error.Abort(k, hint="please check your locale settings") def fromlocal(s): """ Convert a string from the local character encoding to UTF-8 We attempt to decode strings using the encoding mode set by HGENCODINGMODE, which defaults to 'strict'. In this mode, unknown characters will cause an error message. Other modes include 'replace', which replaces unknown characters with a special Unicode character, and 'ignore', which drops the character. """ # can we do a lossless round-trip? if isinstance(s, localstr): return s._utf8 try: return s.decode(encoding, encodingmode).encode("utf-8") except UnicodeDecodeError as inst: sub = s[max(0, inst.start - 10):inst.start + 10] raise error.Abort("decoding near '%s': %s!" % (sub, inst)) except LookupError as k: raise error.Abort(k, hint="please check your locale settings") # How to treat ambiguous-width characters. Set to 'wide' to treat as wide. wide = (os.environ.get("HGENCODINGAMBIGUOUS", "narrow") == "wide" and "WFA" or "WF") def colwidth(s): "Find the column width of a string for display in the local encoding" return ucolwidth(s.decode(encoding, 'replace')) def ucolwidth(d): "Find the column width of a Unicode string for display" eaw = getattr(unicodedata, 'east_asian_width', None) if eaw is not None: return sum([eaw(c) in wide and 2 or 1 for c in d]) return len(d) def getcols(s, start, c): '''Use colwidth to find a c-column substring of s starting at byte index start''' for x in xrange(start + c, len(s)): t = s[start:x] if colwidth(t) == c: return t def trim(s, width, ellipsis='', leftside=False): """Trim string 's' to at most 'width' columns (including 'ellipsis'). If 'leftside' is True, left side of string 's' is trimmed. 'ellipsis' is always placed at trimmed side. >>> ellipsis = '+++' >>> from mercurial import encoding >>> encoding.encoding = 'utf-8' >>> t= '1234567890' >>> print trim(t, 12, ellipsis=ellipsis) 1234567890 >>> print trim(t, 10, ellipsis=ellipsis) 1234567890 >>> print trim(t, 8, ellipsis=ellipsis) 12345+++ >>> print trim(t, 8, ellipsis=ellipsis, leftside=True) +++67890 >>> print trim(t, 8) 12345678 >>> print trim(t, 8, leftside=True) 34567890 >>> print trim(t, 3, ellipsis=ellipsis) +++ >>> print trim(t, 1, ellipsis=ellipsis) + >>> u = u'\u3042\u3044\u3046\u3048\u304a' # 2 x 5 = 10 columns >>> t = u.encode(encoding.encoding) >>> print trim(t, 12, ellipsis=ellipsis) \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a >>> print trim(t, 10, ellipsis=ellipsis) \xe3\x81\x82\xe3\x81\x84\xe3\x81\x86\xe3\x81\x88\xe3\x81\x8a >>> print trim(t, 8, ellipsis=ellipsis) \xe3\x81\x82\xe3\x81\x84+++ >>> print trim(t, 8, ellipsis=ellipsis, leftside=True) +++\xe3\x81\x88\xe3\x81\x8a >>> print trim(t, 5) \xe3\x81\x82\xe3\x81\x84 >>> print trim(t, 5, leftside=True) \xe3\x81\x88\xe3\x81\x8a >>> print trim(t, 4, ellipsis=ellipsis) +++ >>> print trim(t, 4, ellipsis=ellipsis, leftside=True) +++ >>> t = '\x11\x22\x33\x44\x55\x66\x77\x88\x99\xaa' # invalid byte sequence >>> print trim(t, 12, ellipsis=ellipsis) \x11\x22\x33\x44\x55\x66\x77\x88\x99\xaa >>> print trim(t, 10, ellipsis=ellipsis) \x11\x22\x33\x44\x55\x66\x77\x88\x99\xaa >>> print trim(t, 8, ellipsis=ellipsis) \x11\x22\x33\x44\x55+++ >>> print trim(t, 8, ellipsis=ellipsis, leftside=True) +++\x66\x77\x88\x99\xaa >>> print trim(t, 8) \x11\x22\x33\x44\x55\x66\x77\x88 >>> print trim(t, 8, leftside=True) \x33\x44\x55\x66\x77\x88\x99\xaa >>> print trim(t, 3, ellipsis=ellipsis) +++ >>> print trim(t, 1, ellipsis=ellipsis) + """ try: u = s.decode(encoding) except UnicodeDecodeError: if len(s) <= width: # trimming is not needed return s width -= len(ellipsis) if width <= 0: # no enough room even for ellipsis return ellipsis[:width + len(ellipsis)] if leftside: return ellipsis + s[-width:] return s[:width] + ellipsis if ucolwidth(u) <= width: # trimming is not needed return s width -= len(ellipsis) if width <= 0: # no enough room even for ellipsis return ellipsis[:width + len(ellipsis)] if leftside: uslice = lambda i: u[i:] concat = lambda s: ellipsis + s else: uslice = lambda i: u[:-i] concat = lambda s: s + ellipsis for i in xrange(1, len(u)): usub = uslice(i) if ucolwidth(usub) <= width: return concat(usub.encode(encoding)) return ellipsis # no enough room for multi-column characters def _asciilower(s): '''convert a string to lowercase if ASCII Raises UnicodeDecodeError if non-ASCII characters are found.''' s.decode('ascii') return s.lower() def asciilower(s): # delay importing avoids cyclic dependency around "parsers" in # pure Python build (util => i18n => encoding => parsers => util) import parsers impl = getattr(parsers, 'asciilower', _asciilower) global asciilower asciilower = impl return impl(s) def _asciiupper(s): '''convert a string to uppercase if ASCII Raises UnicodeDecodeError if non-ASCII characters are found.''' s.decode('ascii') return s.upper() def asciiupper(s): # delay importing avoids cyclic dependency around "parsers" in # pure Python build (util => i18n => encoding => parsers => util) import parsers impl = getattr(parsers, 'asciiupper', _asciiupper) global asciiupper asciiupper = impl return impl(s) def lower(s): "best-effort encoding-aware case-folding of local string s" try: return asciilower(s) except UnicodeDecodeError: pass try: if isinstance(s, localstr): u = s._utf8.decode("utf-8") else: u = s.decode(encoding, encodingmode) lu = u.lower() if u == lu: return s # preserve localstring return lu.encode(encoding) except UnicodeError: return s.lower() # we don't know how to fold this except in ASCII except LookupError as k: raise error.Abort(k, hint="please check your locale settings") def upper(s): "best-effort encoding-aware case-folding of local string s" try: return asciiupper(s) except UnicodeDecodeError: return upperfallback(s) def upperfallback(s): try: if isinstance(s, localstr): u = s._utf8.decode("utf-8") else: u = s.decode(encoding, encodingmode) uu = u.upper() if u == uu: return s # preserve localstring return uu.encode(encoding) except UnicodeError: return s.upper() # we don't know how to fold this except in ASCII except LookupError as k: raise error.Abort(k, hint="please check your locale settings") class normcasespecs(object): '''what a platform's normcase does to ASCII strings This is specified per platform, and should be consistent with what normcase on that platform actually does. lower: normcase lowercases ASCII strings upper: normcase uppercases ASCII strings other: the fallback function should always be called This should be kept in sync with normcase_spec in util.h.''' lower = -1 upper = 1 other = 0 _jsonmap = {} def jsonescape(s): '''returns a string suitable for JSON JSON is problematic for us because it doesn't support non-Unicode bytes. To deal with this, we take the following approach: - localstr objects are converted back to UTF-8 - valid UTF-8/ASCII strings are passed as-is - other strings are converted to UTF-8b surrogate encoding - apply JSON-specified string escaping (escapes are doubled in these tests) >>> jsonescape('this is a test') 'this is a test' >>> jsonescape('escape characters: \\0 \\x0b \\t \\n \\r \\" \\\\') 'escape characters: \\\\u0000 \\\\u000b \\\\t \\\\n \\\\r \\\\" \\\\\\\\' >>> jsonescape('a weird byte: \\xdd') 'a weird byte: \\xed\\xb3\\x9d' >>> jsonescape('utf-8: caf\\xc3\\xa9') 'utf-8: caf\\xc3\\xa9' >>> jsonescape('') '' ''' if not _jsonmap: for x in xrange(32): _jsonmap[chr(x)] = "\u%04x" %x for x in xrange(32, 256): c = chr(x) _jsonmap[c] = c _jsonmap['\t'] = '\\t' _jsonmap['\n'] = '\\n' _jsonmap['\"'] = '\\"' _jsonmap['\\'] = '\\\\' _jsonmap['\b'] = '\\b' _jsonmap['\f'] = '\\f' _jsonmap['\r'] = '\\r' return ''.join(_jsonmap[c] for c in toutf8b(s)) def toutf8b(s): '''convert a local, possibly-binary string into UTF-8b This is intended as a generic method to preserve data when working with schemes like JSON and XML that have no provision for arbitrary byte strings. As Mercurial often doesn't know what encoding data is in, we use so-called UTF-8b. If a string is already valid UTF-8 (or ASCII), it passes unmodified. Otherwise, unsupported bytes are mapped to UTF-16 surrogate range, uDC00-uDCFF. Principles of operation: - ASCII and UTF-8 data successfully round-trips and is understood by Unicode-oriented clients - filenames and file contents in arbitrary other encodings can have be round-tripped or recovered by clueful clients - local strings that have a cached known UTF-8 encoding (aka localstr) get sent as UTF-8 so Unicode-oriented clients get the Unicode data they want - because we must preserve UTF-8 bytestring in places such as filenames, metadata can't be roundtripped without help (Note: "UTF-8b" often refers to decoding a mix of valid UTF-8 and arbitrary bytes into an internal Unicode format that can be re-encoded back into the original. Here we are exposing the internal surrogate encoding as a UTF-8 string.) ''' if isinstance(s, localstr): return s._utf8 try: s.decode('utf-8') return s except UnicodeDecodeError: # surrogate-encode any characters that don't round-trip s2 = s.decode('utf-8', 'ignore').encode('utf-8') r = "" pos = 0 for c in s: if s2[pos:pos + 1] == c: r += c pos += 1 else: r += unichr(0xdc00 + ord(c)).encode('utf-8') return r def fromutf8b(s): '''Given a UTF-8b string, return a local, possibly-binary string. return the original binary string. This is a round-trip process for strings like filenames, but metadata that's was passed through tolocal will remain in UTF-8. >>> m = "\\xc3\\xa9\\x99abcd" >>> n = toutf8b(m) >>> n '\\xc3\\xa9\\xed\\xb2\\x99abcd' >>> fromutf8b(n) == m True ''' # fast path - look for uDxxx prefixes in s if "\xed" not in s: return s u = s.decode("utf-8") r = "" for c in u: if ord(c) & 0xff00 == 0xdc00: r += chr(ord(c) & 0xff) else: r += c.encode("utf-8") return r