jquery.suggestions: Handle CSS ellipsis better for IE

IE is not impressed by our puny hacks and still reports the width
"in context of" the position in the document, limited by the width
of ancestor elements.

Let's temporarily apply position: absolute; to the involved elements.
This pulls them out of normal document flow and lets us figure out the
real width at last.

Also wrote a proper comment on why we need this stuff.

Verified that this fixes:
* IE 8
* IE 11

Verified that it doesn't break:
* Firefox 3.6
* Firefox 29
* Opera 12
* Opera 22

It *does not* fix IE 6. I don't think that investigating why is a good
use of my time, so I didn't. I84fbae5a made the functionality usable
on IE 6, which feels good enough for me.

Bug: 65224
Change-Id: I4a7357543ca244585ade2061b92f5a6d1e439278

1 files changed, 14 insertions, 2 deletions

diff --git a/resources/src/jquery/jquery.suggestions.js b/resources/src/jquery/jquery.suggestions.js
index a20a948d8214..7a32076ec3cb 100644
--- a/resources/src/jquery/jquery.suggestions.js
+++ b/resources/src/jquery/jquery.suggestions.js
@@ -267,10 +267,22 @@ $.suggestions = {
 							}
 
 							// Widen results box if needed (new width is only calculated here, applied later).
-							// We need this awful hack to calculate the actual pre-ellipsis width.
+
+							// The monstrosity below accomplishes two things:
+							// * Wraps the text contents in a DOM element, so that we can know its width. There is
+							//   no way to directly access the width of a text node, and we can't use the parent
+							//   node width as it has text-overflow: ellipsis; and overflow: hidden; applied to
+							//   it, which trims it to a smaller width.
+							// * Temporarily applies position: absolute; to the wrapper to pull it out of normal
+							//   document flow. Otherwise the CSS text-overflow: ellipsis; and overflow: hidden;
+							//   rules would cause some browsers (at least all versions of IE from 6 to 11) to
+							//   still report the "trimmed" width. This should not be done in regular CSS
+							//   stylesheets as we don't want this rule to apply to other <span> elements, like
+							//   the ones generated by jquery.highlightText.
 							$spanForWidth = $result.wrapInner( '<span>' ).children();
-							childrenWidth = $spanForWidth.outerWidth();
+							childrenWidth = $spanForWidth.css( 'position', 'absolute' ).outerWidth();
 							$spanForWidth.contents().unwrap();
+
 							if ( childrenWidth > $result.width() && childrenWidth > expWidth ) {
 								// factor in any padding, margin, or border space on the parent
 								expWidth = childrenWidth + ( context.data.$container.width() - $result.width() );