Fixes Exception being thrown when the space key is pressed on a CheckBoxCell

[ricardobossan]

Fixes #12752

Root Cause

• The issue occurs because the NotifyMSAAClient method is called without checking if the DataGridView instance is null. This leads to a potential NullReferenceException.

Proposed changes

• Add a null check for the DataGridView instance before calling the NotifyMSAAClient method.

Customer Impact

• Prevents runtime crashes when the DataGridView is null.

Regression?

• No

Risk

• Minimal

Screenshots

Before

After

Test methodology

• Manual testing

Test environment(s)

• 10.0.100-alpha.1.25064.3

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.21594%. Comparing base (77ec5c9) to head (95f04dc).
Report is 3 commits behind head on main.

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #12821         +/-   ##
===================================================
+ Coverage   76.21470%   76.21594%   +0.00124%     
===================================================
  Files           3199        3199                 
  Lines         640488      640492          +4     
  Branches       47227       47228          +1     
===================================================
+ Hits          488146      488157         +11     
+ Misses        148812      148806          -6     
+ Partials        3530        3529          -1     

Flag	Coverage Δ
Debug	76.21594% <100.00000%> (+0.00124%)	⬆️
integration	18.16458% <0.00000%> (-0.00202%)	⬇️
production	50.15642% <100.00000%> (+0.00245%)	⬆️
test	97.04180% <ø> (+0.00055%)	⬆️
unit	47.58381% <100.00000%> (+0.00670%)	⬆️

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[LeafShi1]

LGTM！ For the method NotifyMSAAClient， can we consider remove the Debug.Assert

winforms/src/System.Windows.Forms/src/System/Windows/Forms/Controls/DataGridView/DataGridViewCheckBoxCell.cs

Lines 970 to 972 in 48c153d

	Debug.Assert(DataGridView is not null);
	Debug.Assert((columnIndex >= 0) && (columnIndex < DataGridView.Columns.Count));
	Debug.Assert((rowIndex >= 0) && (rowIndex < DataGridView.Rows.Count));

and replcase it with

if (DataGridView is null ||
    columnIndex < 0 || columnIndex >= DataGridView.Columns.Count ||
    rowIndex < 0 || rowIndex >= DataGridView.Rows.Count)
{
    return;
}

Copilot reviewed 1 out of 1 changed files in this pull request and generated no comments.

[ricardobossan]

Drafted to investigate failing checks.

[Tanya-Solyanik]

With this change you don't need null-check on line 842

[LeafShi1]

Please verify event dataGridView1_CellPainting here to see if NullReferenceException will occur. It seems that the judgment of CurrentCell is not null here is incorrect.

The event was invoked here

winforms/src/System.Windows.Forms/src/System/Windows/Forms/Controls/DataGridView/DataGridViewCell.cs

Line 3674 in e3e5ddc

dataGridView.OnCellPainting(dgvcpe);

, so the judgment should be added before Paint