zed-industries/zed · error

display point out of range

Error message

display point out of range

What it means

An internal invariant guard in FoldPoint::to_offset: converting a FoldPoint to a FoldOffset queries the fold map's transform summary and panics if the given display point lies beyond the map's extent. In practice this means the point was computed against a different (stale or newer) snapshot than the one passed in, or a caller passed an unclamped end-of-buffer point; the fold map only covers rows/folds present in this snapshot.

Source

Thrown at crates/editor/src/display_map/fold_map.rs:147

    #[ztracing::instrument(skip_all)]
    pub fn to_inlay_point(self, snapshot: &FoldSnapshot) -> InlayPoint {
        let (start, _, _) = snapshot
            .transforms
            .find::<Dimensions<FoldPoint, InlayPoint>, _>((), &self, Bias::Right);
        let overshoot = self.0 - start.0.0;
        InlayPoint(start.1.0 + overshoot)
    }

    #[ztracing::instrument(skip_all)]
    pub fn to_offset(self, snapshot: &FoldSnapshot) -> FoldOffset {
        let (start, _, item) = snapshot
            .transforms
            .find::<Dimensions<FoldPoint, TransformSummary>, _>((), &self, Bias::Right);
        let overshoot = self.0 - start.1.output.lines;
        let mut offset = start.1.output.len;
        if !overshoot.is_zero() {
            let transform = item.expect("display point out of range");
            assert!(transform.placeholder.is_none());
            let end_inlay_offset = snapshot
                .inlay_snapshot
                .to_offset(InlayPoint(start.1.input.lines + overshoot));
            offset += end_inlay_offset.0 - start.1.input.len;
        }
        FoldOffset(offset)
    }
}

impl<'a> sum_tree::Dimension<'a, TransformSummary> for FoldPoint {
    fn zero(_cx: ()) -> Self {
        Default::default()
    }

    fn add_summary(&mut self, summary: &'a TransformSummary, _: ()) {
        self.0 += &summary.output.lines;
    }

View on GitHub (pinned to f4178619ac)

Solutions

1. Clamp the FoldPoint to snapshot.max_point()/extent before converting
2. Ensure points and snapshots are taken from the same display map revision — never mix a point from one snapshot with another
3. In callers like chunks_at/chars_at, operate on the snapshot the point was derived from, or re-anchor the point first

When it happens

Trigger: Thrown at crates/editor/src/display_map/fold_map.rs:147 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of zed-industries/zed@f4178619ac (2026-08-20). Data as JSON: /api/errors/06bb249a9ec30f62. Report an issue: GitHub.