wxGrid infinite loop

[hackish]

Sorry I don't have the tools here to make a patch...

In grid.cpp line 6694
You have a loop like so:

do
{

line = oper.GetLineBefore(this, line);

}
while ( line >= 0 && oper.GetLineSize(this, line) == 0 );

When line becomes 0 you have an infinite loop.

The fix is simple:

while ( line > 0 && oper.GetLineSize(this, line) == 0 );

[vadz]

I was sure that I modified GetLineBefore(0) to return -1 but somehow I forgot to do this :-( Will do, thanks for noticing.

[VZ]

(In [73487]) Fix infinite loop in wxGrid::PosToEdgeOfLine().

Return -1 from wxGridRowOperations::GetLineBefore(0) to ensure that we exit
the loop in wxGrid::PosToEdgeOfLine(). Doing this is the logical thing to do
as wxGridColumnOperations::GetLineBefore() already behaved like this and this
was is more expected than returning 0, as the function previously did for some
reason.

Closes #15035.