QPlainTextEdit accessibility is broken

The accessibility of the QPlainTextEdit control is broken.
Steps to reproduce:
1. Compile and run the "Application Example" sample in QT Creator.
2. In the edit box that appears, type this:

Line 1

Line 2

(Line 1, a blank line, and Line 2).

I have the following problems, tested with NVDA on Windows 10:
1. Blank lines aren't read. From line 1, pressing down says Line 1 again, then line 2.
Pressing the down arrow once from Line 1 should say blank.
2. When on the blank line between Line 1 and Line 2, reading the current line says Line 1.
3. There's no blank character at the end of the edit box, I just hear 2 when pressing right arrow at the end of it. Compared to Notepad where it says blank.

Testing with Narrator on Windows 10, the results are similar.
1. When the cursor is at the top of the document, reading the current line (caps lock + up arrow) says Line 1 as expected.
2. Pressing down arrow says end of line. It should say blank.
3. Pressing up arrow says Cap L. It should say Line 1.
4. With the cursor on the L of Line 2, moving up says Line 1, when it should say blank.