Tech and thoughts
Posts tagged bugs
yum: TypeError: rpmdb open failed on Centos
Dec 13th
I had this error and found the solution here.
#rm /dev/urandom #mknod -m 644 /dev/urandom c 1 9
Works like a charm.
Because it seems to me that I used a similar fix for other problem some time ago I wrote it to remember it.

Internet Explorer problem with nested menus over picture
Jul 11th
Couple of days ago I found a rendering problem in Internet Explorer when testing a nested vertical submenu. Click on the picture below and you will see that when you hover the vertical submenus you cannot click on the lower items. The submenu disappears when you scroll over the little spaces between the list items. On Firefox and Chrome you’ll not see this problem.
Internet Explorer bugs are not that rare but this shows in IE8 and the new IE9, and I couldn’t find a fix on the internet.
Here you can see the demo for the hover bug in IE (IE9 inclusive) . The bug is not showing when I remove the test image which the menu overlays.
I tried some tweaks at the margin and padding, z-index and zoom with no result. If this is a known bug or you know other fix than that the one posted below please let me know.
My solution
The solution I found was to put a background to the hover state of the nested menu (#menu ul ul:hover) . I used an 1 by 1 transparent gif (the old days spacer) as a background.
Here is the fixed version using a background with transparent gif. It solves the problem in IE9 and down to IE7.
The bug and the solution seems to remain valid even for the IE10 as I can test it in the preview.
And, if you know some place that rewards this kind of descoveries for IE please point me to it.
Html comments bug on Firefox
Mar 4th
I discovered a bug in Firefox for the html comments. The html comments are broken by a double hyphen “–“.
On the bugzilla it was argued that is not a bug and the implementation is according to the standards http://www.w3.org/TR/html4/intro/sgmltut.html#h-3.2.4 .
The problem is that most web developers are probably not aware of this standard and this could lead to some unexpected results.
In the current version of Firefox (3.6.14) a “–” will close the comment and all that is after will be rendered normally.
In other browsers this will not happen and in the future version Firefox 4 also this will not be a problem, but the standard remains valid.
In Firefox 4 the double hyphen is still interpreted but the comment is closed at the next “>”.
A good practice is to not use html comments for user input expecting that will not show in browser.
If you do need to do that, be aware that functions as php’s htmlentities does not convert double hyphens.
Apparently WordPress knows about this so I can’t show you an example.