Restore the reading position after browser Back

User intention

Read a discussion topic while browsing another user's replies.

The intention is included in the agent’s input prompt alongside environment details and task instructions.

What breaks, and what should happen

Play Both

BeforeThe defect at the parent commit

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Compare the visible replies around Route note 05 before opening its topic and after returning to Replies.

AfterThe same script once the merged fix is applied

0:00.00 / 0:00.00Frame 0

Compare the reading item and its surrounding replies before entering the topic and after returning to the stream.

How is it judged?

01 · Given

Restore the data and starting state.

In a desktop browser, the public Replies activity stream for morgan_reader has more replies than its initial loaded batch. The reader has scrolled far enough to load additional replies and pauses with Route note 05 in Weekend walking plans 01 visible.

02 · When

Perform the interaction.

Open Weekend walking plans 01 through the title link beside Route note 05, then use browser Back to return to the Replies stream.

03 · Judge

Rationale: Opening a topic is a detour from reading the Replies stream. Returning to the same reply lets the reader resume; restoring an offset against only the initial batch can instead land on unrelated replies.

Require

After browser Back and stream loading, the previously viewed reply must be visible at substantially its prior position without manual scrolling or searching. Restore enough previously loaded content to preserve that reading location.

Allowed

Retaining the loaded stream, reloading sufficient items before restoring position, or restoring by a stable reply anchor are acceptable.
Small positioning differences caused by layout settling are acceptable if the same reading item remains visible and usable.
Ordinary new navigation may load fresh data; this case does not require permanently freezing activity streams or a particular history-store implementation.