Closed Bug 271854 Opened 20 years ago Closed 20 years ago

Parser incorrectly closes HTML comments on an XHTML 1.0 Transitional page

Categories

(Core :: DOM: HTML Parser, defect)

Product:
Core
Component:
DOM: HTML Parser
Platform:
x86
Windows XP
Type:
defect
Priority:
Not set
Severity:
minor

Tracking

()

Status:
VERIFIED DUPLICATE of bug 214476

People

(Reporter: aak1ra, Unassigned)

Details

User-Agent:       Opera/7.54 (Windows NT 5.1; U)  [en]
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040803

Hi, i stumped upon this bug during the editing of html page templates for a php 
application i am building. I was editing in the html source the keywords that 
php will replace with values, and was using the syntax below to denote content 
replacement loop start/end points:

<code>
<!-- loop name=loop1 -- start -->
{varsToBeReplaced}
<!-- loop name=loop1 -- end -->
</code>

I'll provide you with some stripped down sample code to make easier to 
replicate:

<code>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.
org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Gecko HTML comments parsing bug</title>
</head>

<body>
<!-- loop -- start -->
<pre>
{var1}
{var2}
</pre>
<!-- loop -- end -->
</body>
</html>
</code>

I figured the use of the double minus '--' in the loop comment, made gecko's 
parser to escape the closing comment tag that followed, and instead close the 
comment on the next comment line it found.

If you run the code above, you'll see nothing on the screen. If the Doctype is 
removed, you'll get the following output:

{var1}
{var2}

I didn't have other Doctypes readily available, so i didn't do any other tests.

All Gecko browsers i tested the page on exhibit the same incorrect behaviour - 
netscape 6, mozilla 1.5, firefox 0.9. Also, i don't think this is a limitation 
of XHTML, as all other browsers i tested (namely opera, ie) parsed the comments 
correctly.

The simple workaround is not to use minuses in comments, but inside a comment it 
should be irrelevant what you type because it's a comment, obviously.

Regards.

Reproducible: Always
Steps to Reproduce:
1. Create an .htm page using the source code i provided above.
2. Preview in mozilla
3. Preview in any other browser
4. Edit the source code, to remove the Doctype declaration.
5. Preview again.
6. Insert back the Doctype, and repeat the process playing with the minuses '--' 
in the comment lines.
Actual Results:  
The page with the Doctype declaration will produce no output. Removing the 
Doctype, or removing the double minuses '--', displays the correct output in the 
browser: {var1} {var2}

Expected Results:  
See above

-
You have two dashes in a row inside the comment. See for bug 214476, why this
gives problems.


*** This bug has been marked as a duplicate of 214476 ***
Status: UNCONFIRMED → RESOLVED
Closed: 20 years ago
Resolution: --- → DUPLICATE
Status: RESOLVED → VERIFIED
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