Respect bold and italic font settings vs control codes and rendering

[un1versal]

Extracted from https://github.com/kvirc/KVIrc/pull/2031

Related to https://github.com/kvirc/KVIrc/issues/2017

Expected behavior

• Italic codes should cancel an italic font, and bold codes should stack in topic widget
• Italic codes should always render even when italic fonts are set in widgets/globally

Actual behavior

• The XOR behaviour of italic codes and stacking of bold codes don't seem to work as intended in the topic widget.

• Italic codes may fail to render [in the output box only] if you change to an italic font, until KVIrc is restarted.
  

System information

System name: Linux 4.4.0-22-generic
System version: #40-Ubuntu SMP Thu May 12 22:03:15 UTC 2016
Architecture: i686
Qt version: 5.5.1
Qt theme: fusion

Screenshots

Topic widget with a normal font (correct): Topic widget with a bold italic font (with missing formatting):

Edited by @AndrioCelos

[staticfox]

Can you recheck this?

[un1versal]

this is totally screwed up

set an italic output font then add text with italc and bold formatting separately press enter

italic formatting is lost, this is wrong should remain simply italic.

[DarthGandalf]

@un1versal your screenshot is correct. Double italic is not italic. That's often used in books to emphasize some word in a sentence which is italic already.