Update ProjectProcessingPage.cpp

[LezheGao]

Fixes #6104

Description of the Change
The root cause of was an unsafe cast of a member function pointer in the static event table:

EVT_PROJECTPROCESSING_STATECHANGE( CProjectProcessingPage::OnStateChange )

This macro forced a cast from void (CProjectProcessingPage::*)(CProjectProcessingPageEvent&) to wxEventFunction (i.e., void (wxEvtHandler::*)(wxEvent&)), which is a cast between incompatible pointer types. Under GCC with -Wcast-function-type, this results in undefined behavior – the this pointer is misadjusted when the event handler is called, causing the state machine (m_iCurrentState, flags, and button enable/disable logic) to read/write garbage memory. Consequently, the wizard’s internal page history becomes corrupted, leading to the looping back behaviour and the back button never being greyed out.
To fix this, the static event table entry for wxEVT_PROJECTPROCESSING_STATECHANGE has been removed and replaced with a type‑safe dynamic binding using Bind() in the Create() method. Bind() uses templates to correctly adjust the this pointer, eliminating the UB and the compiler warning. The other static entries (EVT_WIZARDEX_PAGE_CHANGED and EVT_WIZARDEX_CANCEL) are unchanged because they use compatible function signatures.
After this change, the wizard’s state transitions work correctly, the back button follows the expected page history, and it becomes disabled when appropriate.

Assisted-by: (not using an agent): DeepSeek-V4

Alternate Designs
Keeping the static event table but modify the macro to use wxDECLARE_EVENT_TABLE_ENTRY with a proper functor that performs a safe cast. This would require changes in the header file and deeper understanding of wxWidgets’ internal event mechanism, making it more error‑prone and less maintainable.

Release Notes
Fixed erratic "Back" button behaviour in the project attach wizard (Linux builds from master).

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Summary by cubic

Fixes #6104 by replacing an unsafe static event handler with a type-safe Bind() for the state-change event. The project attach wizard now advances correctly and disables the Back button when expected.

• Bug Fixes
  • Replaced static EVT_PROJECTPROCESSING_STATECHANGE entry with Bind(wxEVT_PROJECTPROCESSING_STATECHANGE, &CProjectProcessingPage::OnStateChange, this) in Create().
  • Left EVT_WIZARDEX_PAGE_CHANGED and EVT_WIZARDEX_CANCEL unchanged.

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}