The Good Life... a weblog about life, technology, and the Opera Web browser

The worst bugs I've found in Opera:

1. [xml] Textarea text size limit: http://my.opera.com/forums/showthread.php?s=&threadid=67025 (bug 151981)
2. Alternative style switcher bug: http://my.opera.com/forums/showthread.php?s=&threadid=91652 (bug 170942)
3. Stripping whitespaces from anchors - differences between browsers: http://my.opera.com/forums/showthread.php?s=&threadid=83322 (bug 137551)

Best regards
Robert Błaut

(Edited 2005/08/25 by Tim - Added bug numbers)

1. iframes not respecting z-index. (bug 87492)

(Edited 2005/08/25 by Tim - Added bug number)

I find that if I install an absolute crapload of fonts on my Windows XP system (we're talking over 2000 of the things), Opera starts to make mistakes.

For instance, my CSS states something like Verdana, Arial, sans-serif, but I have absolutely no idea what font Opera will load from one session to the next. Sometimes I get Impact, sometimes Bodoni, sometimes something completely bizarre. The CSS validates and both Firefox and IE get it right.

It goes back to normal with less fonts on my PC.

Bug 105525

(Edited 2005/08/25 by Tim - Added bug number)

One thing that has been bothering me a while is Opera's trouble with redrawing table rows after changing the row style with javascript (either directly or through className). It's been bugreported through my friend Walter Hoff, and later been tracked down to only being relevant when the table uses thead/tbody/tfoot. Bug nr: 166641. The bugreport should have a simple testcase written by me.

I would also like to second Olly's report, or, somethings wrong with font-support at least. This is a fairly new occurance for me, but I recently hit a site where the following was specified:
font-family: "Gill Sans", Arial, Helvetica, sans-serif;
On a Windows XP computer, with Gill Sans installed, the page displayed with the correct font in Internet Exporer, while Opera as far as I know used Arial in bold! The bold variation came and went through revisions of the stylesheet, with no apparent reason.

The font-bug is just a recent annoyance, which I sadly haven't had time to dig deeper into and create a test case for.

Opera has rendering bugs? Never noticed any...

My long-standing gripe with Presto is with text selection in overflowed divs. The div does not scroll when you drag-select, so you must drag until you select some text outside the div, then drag back and hope you have the text you cannot see selected. Old testcase:

Test case (Bug 114110)

(note: point 2 about mousewheel is fixed; though middle-click scroll would be great if it worked for overflowed divs too).

On the wiki we had lots of discussion about the best way we can overcome this to make users lives easier - in the end we had to introduce a form button to download the raw code for larger code blocks. Gecko handles this just fine; and I hope PrestoII GX-SLI 2000 will handle this better too...

(Edited 2005/08/25 by Tim - Added bug number)

When a div is contained in another unpositioned element but given absolute or fixed positioning, it should then inherit from its containing element (which would be the root element in this case), but this doesn't happen:

http://www.lutz-peter.hoogi.de/extern/Opera/test5.html (Bug 171463)

I remember having to redesign a page after finding there was no way to use the root width for positioned elements like this.

(Edited 2005/08/25 by Tim - Added bug number)

Apart from the very annoying absolute position vs. containing block problem mentioned by a previous poster (test case), here's another one.

If the first child of a list item is floated to the right, the list marker also becomes floated to the right. (Test case). (Bug 170076)

(Edited 2005/08/25 by Tim - Added bug number)

Its an Opera bug, and it happens on the floating div with is more than 20ems width which means the the div overlaps the other div by upto 1em. It pisses me off and its been around for a long time affecting opera only and i a common use css example with normal values.

Example:
http://freexe.com/files/opera_test.html (Bug 166155)

(Edited 2005/08/25 by Tim - Added bug number)

- Repaint problems. In many cases, Opera 'forgets' to repaint part of the screen, causing ugly artifacts. There are most likely many examples in the bug tracking system. I'd love to see a bug-hunt to resolve this issue once and for all.
- Fullscreen doesn't use media='screen', if that's the only thing provided. Originally a design choice for Opera Show, but from the user's point of view it's one hell of a bug, making full-screen only browsing nigh impossible. Solution: if no media='projection' is specified, use 'screen'. This is a *must* fix IMHO. (Bug 118474)
- Happens on some web-applications with draggable items: when you 'drag' a dhtml object, text beneath it is selected. Text should never be selected if there is a layer between the mouse and the text. (Bug 83545)
- Masses of text being selected when keyboard-navigating links. Example: go to http://www.w3.org/TR/2001/CR-css3-selectors-20011113/ and use the a key a couple of times. At some point, large parts of the page are selected. When using keyboard only, this bug pops up from time to time. (Bug 150153)

(Edited 2005/08/25 by Tim - Added bug numbers)

If div has a position: fixed, when I change it to static (or display from block to none), there are a "ghost" of div.
(It usual happen on forums, i.e. my.opera.com)
I wrote a ujs, to add to quick reply this styles:
document.getElementsByName('vbform')[0].style = 'position:fixed; bottom:0; background: #eed; margin:0; float:left; width:700px;';
so it look like http://kostia.gorodok.net/opera/ghost.div.0.png
I add a button with this eventListener
document.getElementsByName('vbform')[0].style.position = document.getElementsByName('vbform')[0].style.position == 'static'?'fixed':'static';
I click to button and get this
http://kostia.gorodok.net/opera/ghost.div.png
after scroll all ghosts dissapear, but it annoying however…

Minimal-ish testcase (self-contained code, but within a larger page), and explanations are at

http://www.dougweb.org/wp/?page_id=121

This is well known, but when you add a PNG background image that has alpha-transparency, Opera slows to a crawl when scrolling the DIV. On fast machines this is not so noticable, but on old machines it can make pages very annoying to read from. It means I try not to use transparent background in respect of users on old machines, which clearly limits the design because of this Presto weakness...

Test here

- There is a bug when image containers are initially as wide as the box containing the alt text, and the image does not shrink to its intrinsic size when it loads. Result: 100*16 px smileys on forums sometimes. Bug 125451.
- Opera renders alt text of images when the page is loading in a non-breaking box which may be far too wide. Result: extremely odd display of table-based forums, and very jumpy effects during pageloading.
Opera should at least render alt text inline and wrappable. Further, I think Opera should not render alt text at all when the image is still loading; only as soon as loading fails or images are disabled.

1. A long-standing bug I've seen on several sites affects textareas in forms, where the contents cannot be scrolled with the mouse, only with the keys. Sometimes half the text in the form is split - one half does scroll, but not the rest. I just made a demo for another bug, and the problem showed up there. I also found a large part of the screen above the form was also moving on scroll! To see this, here's the demo:

   XML Test 2

   That demo also shows another bug - XHTML elements are acted on in XML! (Read my full post about this: XML Browser Differences.) Not sure if that's relevant here or not.

2. I'd also like to see Opera repaint a page when a major change has been made to the CSS. This affects turning on and off styles. For instance, take a trip to the post about XML I linked above. Scroll down past the side menu then turn off CSS. (Ie: press the Author mode button on the View toolbar.) Now turn CSS back on. I see loads of text at the sides left behind by the previous style.

   Sometimes user CSS doesn't go all the way down a page either. (After applying User JavaScript to add a class to the page, coupled with a custom stylesheet to give CSS only to specified sites. I thank an Opera employee for this trick!) On a site I'm restyling it looks like only the div holding the main content gets a new background colour, but scroll past it and the new style stops. The whole page should be recoloured. I haven't been able to get round this one yet.

3. I too have been bitten by odd fonts recently. After installing a couple of Adobe programs and an HP printer at work, I found Opera wasn't showing the right fonts. It was falling back to horrible pixellated ones. It got better after messing around with the fonts, but never solved itself completely. Other browsers were fine. Read up on this (complete with screenshots and testcase) in this Opera forums thread: Font family bug
4. There are many more bugs I've reported over the years, but this is a very odd one: Non-breaking space puts link text in wrong place
5. One last one. Go to any page with grey example boxes of code on the PHP Manual. With zoom set to 100% (normal) press plus or minus to zoom in or out... The grey boxes remain the same font size while the rest of the page changes!

Presto rendering bug with GIF images that have at least one black pixel and transparency, placed as background. Bug appears on any zoom except 100%. (So, try 80%, 90%, 110%... 200%)
Test: http://rusrestaurant.com/tests/opera_bg/

This bug really annoy me as user (because I often use zoom on my 1600x1200 screen) and as web designer.

I think I filled out bug report year ago but can't remember bug #.

This is a rendering engine issue, so I put it here.

Opera should jump to anchor immediately when it is loaded - see how fast is IE and how slowly Opera behaves on this page:
http://www.codeproject.com/aspnet/How_group_RButtons.asp?df=100&forumid=...
(click on other comments and wait until Opera jumps down to them)

This is a major annoyance that harms Opera's image as a speedy browser!

A forum thread about this problem (other examples) is here:
http://my.opera.com/forums/showthread.php?s=&threadid=57198

Happens on http://www.theserverside.com/. The "Post News Items", "More News", "Active Threads" and "XML" links are in the wrong position. View in Firefox to see how it is intended to look.

Here's info about it including the bug #, the rejected mozilla bug and the spec reference.

http://my.opera.com/forums/showthread.php?s=&threadid=78932#post812329

Also, #6 on http://home.tbbs.net/shadow/html/testcases/operabuglist.html will show another test case.

I think this is one of the known positioning bugs, but just in case..

Opera does not handle CSS vertical-align property properly:
#92946 Alignment of inline-blocks and inline-tables is broken
#139051 Inline elements are misaligned
#149813 Baseline of inline-tables is miscalculated
#150941 Baseline of inline-blocks is miscalculated

The biggest problem for me as a user is that minimal font sizes interacts badly with site styles -- but turning off site styling (so that things will get uncovered) also turns off the minimal font size. I'm not sure how many things need to take that real font size into account, but ... more than are doing so.

I will also echo the "No, I didn't want to select everything" bug when using the keyboard" and the "go ahead and jump to the anchor" bugs.

As a developer, the biggest problem is getting access to/applying style rules from javascript, so that I can minimize network round-trips.

Well, last time I checked it out this demo:

http://www.grauw.nl/articles/demos/contentbox.html

...still had a redraw problem in Opera when clicking on the "Click to show/hide more text" link. Don’t know whether that’s still the case in the latest of the latest version.

~Grauw

I ran into some weird problems with applying li:first-line last year. In one case, underlines from links would persist until the end of the page, and in another, list item content would disappear -- but only if it was a single word. The problems would occur even if the style rule didn't apply to anything on the actual page -- as long as it was in the style sheet, it would cause problems. I reported them as bugs 159091 and 159092.

Since neither bug was fixed in Opera 8.0, I ended up removing the rule from the style sheet on one of the sites I maintain. (It had been designed when Opera 6 was current, and the bugs didn't appear until 7.x.)

Full description and test cases at the above link.

Guess the color of the underline?


<a href="#"><font color="red">Why not red underline?</font></a>


Only Opera displays 2 colors:

1. One for text color
2. Another for underline color

See bug 129815.

As seen in the wild at:

• Red headlines on DrudgeReport
• Red section headers at NYTimes
• Menu links at Slate
• Sports section on Excite
• And many other older Quirks sites...

Hello!
There's a high amount of rendering glitches (I call them glitches because they are not actual bugs IMO). These glitches affect the repainting of the document. Meaning, it first renders the page very well, but after resize ... it 'forgets' things.

I have no bug reports regarding these glitches because I can't get them always to happen. For example, there's one thing that is a pain to use on Opera: divs with display table (and table cell). These render properly, sometimes :). They are mostly broken, unreliable implementation.

These repainting problems are most visible in previews and early betas. Still, they are not entirely fixed in final releases.

It's common to encounter these display bugs.

bug #161274

discussion (paritally)

A testcase
Another one (#1 on this page)

I don't have a bug number, but I've been told that the bug has been reported earlier. The problem appears when e.g. using text-decoration: underline for links in a paragraph with justified text (text-align: justify;). The underline border often appears places it's not supposed to. Has this problem been fixed/planned to be fixed?

Another of my "favorites" is that Opera doesn't support video on <object> element (only <embed> works).

forum thread about it

test case

Opera needs to mimic Firefox and IE in this situation because Opera adds too much padding and the rendering appears odd compared to other browsers.

There's a discussion and bug report somewhere in the web design forum, but am unable to find it. This was an actual problem on a some sites.

The first one is widely known, and I have a feeling you fixed it already:
Absolute in fixed align and visual problems
Second:
Extra :after's on innerHTML change

This is not the whole list but the rest relates to mainly javascript problems, so I had to omit them (6 more to be precise)

hi,
i noticed that when i change the SelectedIndex of a <SELECT> box using javascript, Opera doesn't (always) change the value on the screen (the correct value is sent with the form). to show the correct value i have to move the mouse over the select box (no need to click), or change tab.
so far, to make it work i use a jscript method : forms.myform.elements['selectitem'].focus();

another bug : when i click over a <INPUT type="text" disabled>, the click is not detected by a document.onclick=dosomething();
(the problem is when the input is disabled).

I think the first one is a bug but the second I'm not so sure about.

When I specify a 0 width/height for images, in either the html or the css Opera will show them with 1px height/width. Example (P.S. It doesn't really)

When using frames, if I only want them to be a certain width/height and then leave the rest of the screen blank, I use "*" as a width/height value and don't specify a frame for it. This works fine in IE/win and Firefox but Opera stretches the frames to fill the screen. Example.

Oh and valid XHTML 1.0 Strict/1.1 image maps don't seem to work.

Sorry for a lack of bug reports and test cases, but I'm only an amatuer at all this.

Greeting Tim! Thanks for this blog. Bug 182008 is very distressing which hangs or jams Opera for almost 2 minutes or more before loading the page http://journal.gaurangapada.com which has a basic javascript menu on the top. This pages loads instantly in firefox and ie though. This js menu is used by me to design a lot of pages and is made by one of the most popular dhtml menu building programs in the world allwebmenus at likno.com . It has been reported by many other Opera users at http://my.opera.com/community/forums/findpost.pl?id=1119822 . And the moment I disable js, it loads instantly. So there seems to be some conflict with the js and Opera. Please kindly fix it.