Open Radar

 
Description:

I have come across a few places in iOS 10.3 and iOS 10.3.1 where the strikethrough attribute on an attribute string is not being displayed in a UILabel.

1) If the strikethrough attribute does not span the entire length of the string the strikethrough will not display on the text in UILabel.
2) If the attributed string containing a strikethrough also contains a paragraph style that sets the lineHeightMultiplier, minimumLineHeight, or maximumLineHeight value is set the strikethrough will not display on the text in a UILabel.

All of the above cases worked correctly in iOS 10.2 and before but no longer render the strikethrough as of iOS 10.3.


Steps to reproduce:
Case 1:
1) Create an NSMutableAttributedString with no attributes.
2) Add to that string an attributes dictionary containing an NSUnderlineStyleValue other than .styleNone for the key NSStrikethroughStyleAttributeName for less than the entire range of the string.
3) Set that attributed string on a UILabel

Case 2:
1) Create an NSAttributedString with an attributes dictionary containing an NSUnderlineStyleValue other than .styleNone for the key NSStrikethroughStyleAttributeName and an NSParagraphStyle with a lineHeightMultiple of 1.5.
2) Set that attributed string on a UILabel


Expected Results:
Case 1:
The displayed text should contain a visible strikethrough for the specified range.

Case 2:
The displayed text should contain a visible strikethrough for the entire range.


Actual Results:
There is no visible strikethrough.