Fix array bounds underflow

[Rainyan]

Description

Fix a case of potential array bounds underflow by NeoUI::TextEditChIdxFromMouse for empty inputs.

Steps to reproduce

• checkout current master 04569ec
• Build & launch the game
• Click "Create Server"
• Empty the "Password" field's value
• Press escape to return to main menu
• Click "Create Server" again
• Now the Password field's value should be empty
• Add a breakpoint to line:

  neo/src/game/client/neo/ui/neo_ui.cpp

  Line 2008 in 04569ec

  if (iMouseOnXWidth >= c->irTextWidths[iWszTextSize - 1])

• Click the empty "Password" field with your mouse
• The breakpoint should be hit

What happens

• Value of iWszTextSize is 0
• Therefore, at

  neo/src/game/client/neo/ui/neo_ui.cpp

  Line 2008 in 04569ec

  if (iMouseOnXWidth >= c->irTextWidths[iWszTextSize - 1])

  the irTextWidths is indexed at -1 which is out array bounds.

What should happen

• irTextWidths access stays in bounds

Toolchain

• Windows MSVC VS2022

Linked Issues