2756 - Line breaks within ALT text rendered as box-like char ( )

Status: VERIFIED FIXED

(Core Graveyard :: Viewer App, defect, P2)

Description

[Eli Goldberg]

* TITLE/SUMMARY
Line breaks within ALT text rendered as box-like char ()

* STEPS TO REPRODUCE
0) Launch Viewer
1) Load http://www.prometheus-music.com/gecko/bug694a.html [included below as
'HTML SNIPPET']

* RESULT
 - What happened

Text rendered in ALT test is linebreak.

 - What was expected

Behavior equivalent to IE 4.0 or Comm 4.5, unless this behavior is specified in
the HTML 4 spec. (I don't see anything in 13.8, "How to specify alternate text".)


* REGRESSION

 - Occurs On
        viewer (1.27.99 optimized build for Mac OS)
        viewer (1.27.99 optimized build for Win32 [NT 4, Service Pack 3])
        viewer (1.27.99 optimized build for Linux)

 - Doesn't Occur On
        Communicator 4.5 (RTM build tested on Mac OS)
        IE 4.0 (Win32; displays an actual line break in the alt text)

* HTML SNIPPET

<img src="bla.gif" width=200 height=200 alt="line
break">

* CONFIGURATIONS TESTED

- [Mac] Power Mac 8500/120 (233 Mhz 604e), 64 MB RAM (VM on; 1 MB of VM used),
1024x768 (Thousands of Colors), Mac OS 8.5.1

- [Win32] Vectra VL (233 Mhz P2), 96 MB RAM, 800x600 (True Color), NT 4.0 SP3.

- [Linux] Vectra VL (266 Mhz P2), 32 MB RAM (blech).

Comment 1

[Eli Goldberg]

[Communicator 4.5 displays the text as 'linebreak', filtering out the line break
character entirely.]

Comment 2

[Hixie (not reading bugmail)]

I would recommend that you treat the line break character as a space rather
than nothing at all.

That way, this code snippet's alt text:

   <img src="bla.gif" width=200 height=200 alt="this is
   some text">

...would be rendered as "this is some text" not "this issome text".

This should apply to *all* textual attributes, including "title", "alt",
"summary", etc.

Comment 3

[Eli Goldberg]

I see this is Resolved/Fixed, but what are the expected results? [i.e. treat line
break as a space, or yank 'em out, or...?]

Anyway, I'll verify irregardless, but it would help to know.

Comment 4

[Eli Goldberg]

Re-opening bug. Checked 2.1.99 build on Mac OS, Win32 and Linux.

On Linux, a Yen character is displayed instead of the character-not-available
box.

On Win32 and Mac, I concur with py8ieh's suggestion that inserting a space
between words separated by a line break rather than a space makes much more
sense, rather than simply concatenating the two words together into a single
word. (Which IE 4 already does.)

Thus, re-opened for Linux fix, and to request consideration for py8ieh's
suggestion.

Comment 5

[Eli Goldberg]

Oops. I meant:

"...concur with py8ieh's suggestion that inserting a space between words
separated by a line break makes much more sense than simply concatenating the two
words together into a single word."

Comment 6

[leger]

Setting all current Open/Normal to M4.

Comment 7

[Hixie (not reading bugmail)]

Here is what HTML4 spec says about the contents of CDATA attributes such as
alt, title, href, longdesc...:

CDATA is a sequence of characters from the document character set and
may include character entities. User agents should interpret attribute
values as follows:
 o Replace character entities with characters,
 o Ignore line feeds,
 o Replace each carriage return or tab with a single space.
User agents may ignore leading and trailing white space in CDATA attribute
values (e.g., "   myval   " may be interpreted as "myval").

                      from http://www.w3.org/TR/REC-html40/types.html#h-6.2

Comment 8

[Eli Goldberg]

"It's not just a good idea, it's the spec!" (thanks!)

Comment 9

[rickg]

I think this is fixed now. Please verify.

Comment 10

[Eli Goldberg]

Hmm....not fixed in 2.12.99 Mac OS build, but will hold for 2.16.99 cross-
platform builds and verify or re-open.

Comment 11

[Eli Goldberg]

Verified fixed using:

	- 2.18.99 Mac OS build
	- 2.18.99 Win32 build
	- 2.22.99 Linux build

[Mac OS & Linux builds have text replaced with a broken image upon resize; will
write up a separate bug if one doesn't exist.]

Thanks!

Comment 12

[Eli Goldberg]

[Side issue covered by bug #2723.]

Also, checked a small number of other instances of CDATA attributes (thanks
py8ieh!), and didn't observe line break handling problems.

Comment 13

[Hixie (not reading bugmail)]

This bug is one of many related to alternate text of images. All these bugs
have been marked. To find related bugs, search the description field for the
string "[ALT]".