wrong return value of getInlineStyleForCollapsedSelection and getInlineStyleForNonCollapsedSelection

[psybor]

Do you want to request a feature or report a bug?

bug.

What is the current behavior?

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem. You can use this jsfiddle to get started: https://jsfiddle.net/gmertk/e61z7nfa/.

https://draftjs.org/

1. first line ends with bold.
2. second line starts with italic.
3. move to the start of second line, press enter. press up to move the cursor to the newly created line.
4. input words.
   you can see it inherited the first line's bold.

What is the expected behavior?

When startOffset is 0, and startBlock.getLength() is 0, getInlineStyleForCollapsedSelection and getInlineStyleForNonCollapsedSelection should return empty OrderedSet() rather than lookUpwardForInlineStyle;

Which versions of Draft.js, and which browser / OS are affected by this issue? Did this work in previous versions of Draft.js?