fix: OSK and message dialog crash from GU display list misuse

[AndrewAltimit]

Summary

• Move sceUtilityOskUpdate and sceUtilityMsgDialogUpdate calls outside the open GU display list frame, matching the PSPSDK convention that utility dialog updates must not be called within sceGuStart/sceGuFinish blocks
• Add a cleared background frame (opaque black) before each dialog update so the dialog renders correctly
• Break on negative status codes (error states) to avoid infinite polling
• Add post-loop shutdown drain: if the dialog reached QUIT (3) or FINISHED (4) but the polling loop timed out before draining to NONE (0), properly call ShutdownStart and wait for the state machine to complete

Affected files

• psp/src/osk.rs -- On-Screen Keyboard dialog
• psp/src/dialog.rs -- Message/confirm/error dialogs

Test plan

• EBOOT builds with RUST_PSP_BUILD_STD=1 cargo +nightly psp --release
• OSK opens without crash in PPSSPP (automated test via scripts/test-osk-ppsspp.sh in oasis-os)
• Message dialog (confirm_dialog in rm command) follows same fix pattern
• Manual test on real PSP hardware

Generated with Claude Code

[github-actions]

Gemini AI Code Review

Issues

(none)

Previous Issues

(none)

Suggestions

• psp/src/dialog.rs:160 - The cleanup loop (120 iterations) uses sceDisplayWaitVblankStart() which is ~2 seconds of blocking time. While appropriate for a safety drain, consider if a shorter timeout is sufficient given that the main loop already ran for up to 600 iterations.
• psp/src/osk.rs:227 - Same as above; 120 iterations is a safe but long timeout for a background drain.

Notes

• The fix correctly addresses the GU display list state machine conflict. Moving sceUtility*Update calls outside the sceGuStart/sceGuFinish block is the standard PSPSDK requirement to prevent the utility library from attempting to open its own display list while one is already active on the same context.
• The addition of sceGuClear ensures that the dialog background doesn't contain garbage data from previous frames, improving visual consistency.
• The use of 0xff00_0000 (opaque black) for clear color is correct for the PSP's ABGR/RGBA color formats depending on the display mode, providing a neutral backdrop for system dialogs.
• Error handling for status < 0 in the loop condition is a good hardening measure against hardware/firmware failures that would previously cause infinite polling.

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Generated by Gemini AI (gemini-3-flash-preview). Supplementary to human reviews.

[AndrewAltimit]

Review Response Agent (Iteration 1)

Status: No changes needed

Fixed Issues

• (none - no legitimate issues found)

Ignored Issues

• Gemini suggestion about 120-iteration cleanup loop timeout (dialog.rs:149, osk.rs:218): This is a reasonable safety margin for draining the dialog state machine. The loop breaks early on success, so the 120 cap is only hit in pathological cases. Not worth reducing.

Deferred to Human

• (none)

Notes

• Gemini review found no issues; only made optional suggestions about timeout length
• Codex review failed entirely due to OpenAI rate limiting (HTTP 429) and produced no feedback
• Both dialog.rs and osk.rs correctly implement the PSPSDK convention of calling utility dialog updates outside GU display list frames
• The shutdown drain loops properly handle the QUIT(3) -> FINISHED(4) -> NONE(0) state transitions

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The agent reviewed feedback but determined no code changes were required.