As mentioned on python-dev, reverting patch #1504333 because it introduced
an infinite loop in rev 47154.

This patch also adds a test to prevent the regression.

(modified patch by Sam Ruby; changed to use separate REs for start and end
 tags to reduce matching cost for end tags; extended tests; updated to avoid
 breaking previous changes to support IPv6 addresses in unquoted attribute
 values)

  ('[' and ']' were not accepted in unquoted attribute values)

- cleaned up tests of character and entity reference decoding so the
  tests cover the documented relationships among handle_charref,
  handle_entityref, convert_charref, convert_codepoint, and
  convert_entityref, without bringing up Unicode issues that sgmllib
  cannot be involved in

(implementation/tests contributed by Sam Ruby)

From SF patch #852334.

Added test that checks for characters allowed in the query part of URLs.
Backport candidate.

This closes SF patch #669683.

happy.  (This does not cover everything it complained about, though.)

Use a new internal method, error(), consistently to raise parse errors;
the new base class also uses this.
Adjust the parse_comment() method to return the new offset into the buffer
instead of the number of characters scanned; this was the only helper
method that did it this way, so we have better consistency now.  Required
to share the new base class.
This fixes SF bug #448482 and #453706.

This closes SF patch #440153.

entity references are not allowed in that mode.

Do a better job of scanning <!DOCTYPE ...> declarations; based on the
code in HTMLParser.py.

this module slightly more resiliant in the face of XHTML input, or just
colons in attribute names.

values.  The change for attribute values matches the way Mozilla and
Navigator view the world, at least.

This closes SF bug #436621.

basically accept <!...> where the dots can be single- or double-quoted
strings or any other character except >.

Background: I found a real-life example that failed to parse with
the old assumption: http://www.opensource.org/licenses/jabberpl.html
contains a few constructs of the form <![if !supportLists]>...<![endif]>.

found by Neil Norwitz's PyChecker.

for backward compatibility.

Add support for SGML declaration syntax (<!....>) to some reasonable
degree.  This does not support everything allowed in SGML, but should
work with "real" HTML (internal subset in a DOCTYPE is not handled).
The content of the declaration is passed to the .handle_decl() method,
which can be overridden by subclasses.

sgmllib does not recognize HTML attributes containing the semicolon
';' character. This may be in accordance with the HTML spec, but there
are sites that use it (excite.com) and the browsers I regularly use
(IE5, Netscape, Opera) all handle it. Doug Fort Downright Software LLC

also modified check_all function to suppress all warnings since they aren't
relevant to what this test is doing (allows quiet checking of regsub, for
instance)

int().

Use != instead of <> since <> is documented as "obsolescent".
Use "is" and "is not" when comparing with None or type objects.

get_starttag_text():  New method.
        Return the text of the most recently parsed start tag, from
        the '<' to the '>' or '/'.  Not really useful for structure
        processing, but requested for Web-related use.  May also be
        useful for being able to re-generate the input from the parse
        events, but there's no equivalent for end tags.

attrfind:  Be a little more forgiving of unquoted attribute values.

The attached patches update the standard library so that all modules
have docstrings beginning with one-line summaries.

A new docstring was added to formatter.  The docstring for os.py
was updated to mention nt, os2, ce in addition to posix, dos, mac.

of them.  I.e., '<a name="foo"href="bar.html">' will now have two
attributes recognized.

Based on comments from newgroup.

with tags that have - or . in their names.