Update QMarkdownTextEdit::handleBracketClosing to fix issue caused by #208

[com3dian]

No description provided.

[pbek]

Can you please provide an example Markdown with a bracket closing issue that this PR is fixing?

[com3dian]

Hi @pbek , sorry for this late reply but I was busy recently.

So this PR fixed the issue caused by my last one (#208), in which I changed index calculation method to consider indented white-spaces:
https://github.com/pbek/qmarkdowntextedit/pull/208/files/eebf03aa09e7366d68f3d16fa8ecdfc8ca4b8d01

However in line 722,

qmarkdowntextedit/qmarkdowntextedit.cpp

Line 722 in 48d602b

bool isNextAsterisk = pib < text.length() && text.at(pib) == '*';

and line 724,

qmarkdowntextedit/qmarkdowntextedit.cpp

Line 724 in 48d602b

if (pib < text.length() && !isMaybeBold && !text.at(pib).isSpace()) {

no check for negative pib is there is there yet, so that may cause a crash. When the user have the following line:

 
  |      some text
^ ^ ^^^^^
  cursor
// In this case the `text` variable is "some text" while `pib` is -6 (original index:3 - indented length:9)

and type asterisk * will trigger this issue.

By adding the condition pib > 0, the crash will be fixed and the method will return without triggering any bracket completions, which suppose the user has a multi-level list.

[pbek]

Can you please provide a step-by-step instruction what to do to reproduce the crash, so I can test this?

[com3dian]

Sure,

If the user start a newline like

  |      some text
^ ^ ^^^^^
  cursor
// In this case the `text` variable is "some text" while `pib` is -6 (original index:3 - indented length:9)

and the vertical bar is the cursor, then if the user input an asterisk * a crash will be triggered.

[pbek]

I wasn't able to reproduce this.

Can you please provide a step-by-step instruction what to type to reproduce the crash?