26583 - Inner of nested <A HREF> Links does not work

Status: VERIFIED FIXED

(Core :: Layout, defect, P1)

Description

[Richard Ekle]

On this page is a bunch of links.  If you click on some of the links, Mozilla
reports a 404 error.  These links work successfully in IE 5.0.

Try the "Making application programming easy with GNOME libraries" for an
example of this problem.

Comment 1

[Ross Brackett]

Confirmed.  At first I thought it was bad JavaScript, but instead it's due to 
this little perplexing gem, since this code fragment alone STILL works in IE:

<pre><font size = -1>
&lt;A 
HREF="/developer/papers.nsf/ed4512170f732bcb852567af000db1fe/cc9ecb5aacc40662852
567ef000dea6d?OpenDocument"&gt;
&lt;FONT FACE="HELVETICA,HELV,ARIAL" SIZE="-1"&gt;
&lt;A HREF="http://www-4.ibm.com/software/developer/library/michael-tiemann-
interview.html"&gt;
&lt;B&gt;An interview with Michael Tiemann 
&lt;/B&gt;&lt;/A&gt;&lt;/FONT&gt;&lt;BR&gt;&lt;BR&gt;
&lt;/A&gt;&lt;/FONT&gt;
<font size = -1>
</pre>
<br>
I'm not familiar with what effect this is supposed to achive.  In fact, I've 
never seen anything remotely like this.  Anybody care to comment on this coding 
style.

Also, I should add that 
http://www2.software.ibm.com/developer/papers.nsf/ed4512170f732bcb852567af000db1
fe/cc9ecb5aacc40662852567ef000dea6d?OpenDocument

Doesn't work in IE, so the problem could be that this is an IE-only "feature" 
and that the fallback is supposed to be to the link above, but it doesn't work 
because IBM simply forgot.  Hope this helps.

Comment 2

[Ross Brackett]

Sorry, I think the first code fragment should actually look like this:

<A 
HREF="/developer/papers.nsf/ed4512170f732bcb852567af000db1fe/cc9ecb5aacc40662852
567ef000dea6d?OpenDocument">
<FONT FACE="HELVETICA,HELV,ARIAL" SIZE="-1">
<A HREF="http://www-4.ibm.com/software/developer/library/michael-tiemann-
interview.html">
<B>An interview with Michael Tiemann </B></A></FONT><BR><BR>
</A></FONT>

If that comes out wrong, I think you still get the general idea.

Comment 3

[Sean Richardson]

The HTML code snippet has nested <A> elements, which are strictly forbidden
by the HTML 4 spec. 

The closest bug to this seems to be bug 23780, "Anchor element not closed by 
second <A>", REOPENED. If that bug were fixed, the first <A HREF> would be
closed before it had any content, the second <A HREF> ought to work, and
the second </A> would be leftover garbage.

Comment 4

[Christine Begle]

*** Bug 26949 has been marked as a duplicate of this bug. ***

Comment 5

[rickg]

This is a problem we need to fix for beta, me thinks.

*** This bug has been marked as a duplicate of 3944 ***

Comment 6

[Ron Gavlin]

This bug is still not fixed in the 2000030623 build. I suspect it was 
incorrectly marked as a duplicate of bug #3944.

Comment 7

[harishd]

here is a further reduced case:

<A HREF="foo.htm">
<FONT>
<A HREF="http://www.mozilla.org">Take me to mozilla.org not to foo.htm

Comment 8

[harishd]

Content model:

docshell=01101970
html@0203E2CC refcount=3<
  head@02038BDC refcount=2<
  >
  body@0201054C refcount=3<
    a@0204D9BC href=foo.htm refcount=3<
      Text@0204D780 refcount=3< \n>
      font@0204D71C refcount=3<
        Text@0204D5F0 refcount=3<\n>
        a@0204D58C href=http://www.mozilla.org refcount=3<
          Text@0204D350 refcount=3<Take me to mozilla.org not to foo.htm\n>
        >
      >
    >
  >
>

Comment 9

[harishd]

I'll take this..

Comment 10

[harishd]

Attachment: Patch to fix the bug [ Caution: Haven't tested throughly ].

Comment 11

[harishd]

Attachment: A better patch

Comment 12

[harishd]

Ex: <A><B><A>  
- Here the inner <A> should be informed about the outer <A> ( Anchor cannot 
contain self ). FIXED by tweaking DTD's containment rules.

Comment 13

[Chris Petersen]

Marking verified with the May 22nd build.

Comment 14

[Heikki Toivonen (remove -bugzilla when emailing directly)]

SPAM. HTML Element component deprecated, changing component to Layout. See bug
88132 for details.

Comment 15

[Greg K.]

*** Bug 188234 has been marked as a duplicate of this bug. ***