Infinite scroll busy loop when reaching end of book causes UI freeze

[tuomas2]

Description

When scrolling to the end of a Bible book (e.g. Ecclesiastes 12:14), the infinite scroll logic enters a busy loop where requestMoreToEnd returns null (no more chapters) but the Vue.js side keeps requesting more content indefinitely.

This causes:

• Main thread saturation from continuous JS bridge calls (~15ms per iteration)
• UI appearing frozen/hung, especially on slower devices
• Excessive battery drain

In the reported case, 1166 null responses were logged over 28 minutes on an Onyx Go103 e-ink reader.

Steps to reproduce

1. Open any Bible book
2. Navigate to the last chapter (e.g. Ecclesiastes 12)
3. Scroll to the bottom of the chapter
4. The app becomes unresponsive

Root cause

loadTextAtEnd() in infinite-scroll.ts calls itself recursively when needsMoreContent() returns true. The consecutiveEmptyLoads safety counter was local to processQueues() and reset on every recursive call, so the loop never terminated.

Fix

Added reachedEnd/reachedStart flags that persist across recursive calls and are reset on document change (passage navigation). Committed in d9ed120.

Device info

• App version: 5.0.915
• Device: Onyx Go103 (e-ink reader)
• Android: 12 (SDK 32)

OSTicket: https://support.andbible.org/scp/tickets.php?id=3177