Prettified code copied in Internet Explorer pastes without line breaks

Question

When you copy a block of "pretty printed" code in Internet Explorer 8 and paste it in notepad, all text appears on one line. See for example:

Hello
This is some code
This is the third line of the code

This will appear as:

Hello This is some code This is the third line of the code
0x20-^                 ^
0x20-------------------|

Answer 1

The cause is that Stack Overflow's version of prettify only checks for IE6, IE7 and IE8. When IE9 came out, the old workaround stopped working!

From: https://stackoverflow.com/content/js/prettify-full.js (2011-06-13):

window._pr_isIE6=function()
{
    var a = navigator && navigator.userAgent &&
        navigator.userAgent.match(/\bMSIE ([678])\./);
    ...
}

Answer 2

The problem should only occur when Prettify kicks in, because when that happens the literal newlines are replaced in the DOM with <br> elements (which IE doesn't respect in this case, for whatever reason). From a quick test, since the code is inside of a <pre> anyway, not replacing the newlines seems to work consistently across browsers (IE8/9, Firefox 3.6/4, Chrome 11/13, Safari 5, Opera 11) so long as you don't include the <br> elements.

I think that Prettify is responsible for this swap in the first place, so preventing it might be problematic. However, it might be possible to add in a post-processing hook that undoes this operation. I'll look into that later to see what might be involved and to verify that this won't cause any other issues.

Edit: It seems that this issue was already well-documented, so the real question as waiwai993 points out is what caused the regression?

Answer 3

I can confirm that this is currently a problem with IE9. See for example this SO answer. I can copy/paste using Chrome 11 fine, but with IE9 I get everything on a single line.