diff --git a/crates/algo/src/warp.rs b/crates/algo/src/warp.rs
index 188de07d47..54a6c7c868 100644
--- a/crates/algo/src/warp.rs
+++ b/crates/algo/src/warp.rs
@@ -14,8 +14,9 @@
 //! later (lower-right) cell wins. Work is split per destination tile (parallel on native).
 
 use photocraft_color::PixelFormat;
-use photocraft_geom::Rect;
-use photocraft_raster::Surface;
+use photocraft_geom::{Rect, TileCoord};
+use photocraft_raster::{Surface, Tile};
+use std::sync::Arc;
 
 use crate::transform::{Interp, bicubic};
 
@@ -207,7 +208,7 @@ pub fn warp_triangles(src: &Surface, src_rect: Rect, verts: &[([f64; 2], [f64; 2
     }
     let n = fmt.channels();
     let a = n - 1;
-    let work = |(t, tris): (&Rect, &Vec<[usize; 3]>)| -> Option<(Rect, Vec<f32>)> {
+    let work = |(t, tris): (&Rect, &Vec<[usize; 3]>)| -> Option<(TileCoord, Arc<Tile>)> {
         if tris.is_empty() {
             return None;
         }
@@ -296,6 +297,11 @@ pub fn warp_triangles(src: &Surface, src_rect: Rect, verts: &[([f64; 2], [f64; 2
                 f64::from(px[((y - foot.y0) as usize * fw + (x - foot.x0) as usize) * n + c])
             }
         };
+        // Offset of pixel (x, y) when the `taps` x `taps` block from it lies inside `foot`, so
+        // the samplers can index `px` directly instead of bounds-checking every tap.
+        let base = |x: i32, y: i32, taps: i32| -> Option<usize> {
+            (x >= foot.x0 && y >= foot.y0 && x + taps <= foot.x1 && y + taps <= foot.y1).then(|| ((y - foot.y0) as usize * fw + (x - foot.x0) as usize) * n)
+        };
         let mut outp = vec![0.0f32; w * h * n];
         let mut any = false;
         let mut acc = [0.0f64; 8];
@@ -313,6 +319,17 @@ pub fn warp_triangles(src: &Surface, src_rect: Rect, verts: &[([f64; 2], [f64; 2
                 Interp::Bilinear => {
                     let (ix, iy) = (u.floor() as i32, v.floor() as i32);
                     let (fx, fy) = (u - f64::from(ix), v - f64::from(iy));
+                    if let Some(o) = base(ix, iy, 2) {
+                        for (dy, wy) in [(0, 1.0 - fy), (1, fy)] {
+                            for (dx, wx) in [(0, 1.0 - fx), (1, fx)] {
+                                let p = &px[o + (dy * fw + dx) * n..][..n];
+                                for (s, v) in acc.iter_mut().zip(p) {
+                                    *s += f64::from(*v) * wx * wy;
+                                }
+                            }
+                        }
+                        return;
+                    }
                     for (dy, wy) in [(0, 1.0 - fy), (1, fy)] {
                         for (dx, wx) in [(0, 1.0 - fx), (1, fx)] {
                             for (c, s) in acc.iter_mut().enumerate().take(n) {
@@ -327,6 +344,21 @@ pub fn warp_triangles(src: &Surface, src_rect: Rect, verts: &[([f64; 2], [f64; 2
                     let (u, v) = (snap(u), snap(v));
                     let (ix, iy) = (u.floor() as i32, v.floor() as i32);
                     let (wx, wy) = (bicubic(u - f64::from(ix)), bicubic(v - f64::from(iy)));
+                    if let Some(o) = base(ix - 1, iy - 1, 4) {
+                        for (j, wyj) in wy.iter().enumerate() {
+                            for (i, wxi) in wx.iter().enumerate() {
+                                let k = wxi * wyj;
+                                if k == 0.0 {
+                                    continue;
+                                }
+                                let p = &px[o + (j * fw + i) * n..][..n];
+                                for (s, v) in acc.iter_mut().zip(p) {
+                                    *s += f64::from(*v) * k;
+                                }
+                            }
+                        }
+                        return;
+                    }
                     for (j, wyj) in wy.iter().enumerate() {
                         for (i, wxi) in wx.iter().enumerate() {
                             let k = wxi * wyj;
@@ -378,19 +410,27 @@ pub fn warp_triangles(src: &Surface, src_rect: Rect, verts: &[([f64; 2], [f64; 2
             }
             outp[b + a] = al as f32;
         }
-        any.then_some((*t, outp))
+        if !any {
+            return None;
+        }
+        // Encoded (and dropped if fully transparent) here, in parallel, rather than one tile at
+        // a time once all are done. `t` lies in one tile.
+        let mut one = Surface::new(fmt);
+        one.write_region(*t, &outp);
+        one.prune();
+        if one.tile_count() == 0 {
+            return None;
+        }
+        one.take_tiles(*t).pop()
     };
     #[cfg(not(target_arch = "wasm32"))]
-    let done: Vec<(Rect, Vec<f32>)> = {
+    let done: Vec<(TileCoord, Arc<Tile>)> = {
         use rayon::prelude::*;
         tiles.par_iter().zip(bins.par_iter()).filter_map(work).collect()
     };
     #[cfg(target_arch = "wasm32")]
-    let done: Vec<(Rect, Vec<f32>)> = tiles.iter().zip(bins.iter()).filter_map(work).collect();
-    for (r, v) in done {
-        out.write_region(r, &v);
-    }
-    out.prune();
+    let done: Vec<(TileCoord, Arc<Tile>)> = tiles.iter().zip(bins.iter()).filter_map(work).collect();
+    out.put_tiles(done);
     out
 }
 
diff --git a/crates/codecs/src/codecs/tiff_exif.rs b/crates/codecs/src/codecs/tiff_exif.rs
index d07f555f30..00d47d0702 100644
--- a/crates/codecs/src/codecs/tiff_exif.rs
+++ b/crates/codecs/src/codecs/tiff_exif.rs
@@ -6,7 +6,9 @@
 //! the same reader ([`super::tiff_ifd::File`]): reading a TIFF builds a block from the file's own
 //! directories, writing one copies the block's directories into the file. Values are copied as
 //! bytes (re-ordered when the byte orders differ), so tags PhotoCraft doesn't know survive.
-//! Classic TIFF only on the reading side: an EXIF block has 4-byte offsets.
+//! Classic TIFF only on the reading side: an EXIF block has 4-byte offsets. What is copied is
+//! bounded by the stream's own size and a fixed cap, because entries of a hostile file can
+//! overlap (see [`read`]).
 
 use tiff::encoder::{DirectoryEncoder, TiffEncoder, TiffKind};
 use tiff::tags::{Tag, Type};
@@ -27,6 +29,11 @@ const TAG_INTEROP_IFD: u16 = 40965;
 const IFD0_TAGS: [u16; 7] = [270, 271, 272, 305, 306, 315, 33432];
 /// At most this many entries are copied from one directory.
 const MAX_FIELDS: usize = 1024;
+/// At most this many value bytes are copied from one stream, over all its directories. Real EXIF
+/// is far smaller (the largest Nikon maker note seen is under 1 MB); the cap leaves room for
+/// that and for a few such notes. A stream never yields more than its own length either (see
+/// [`read`]).
+const MAX_COPIED_BYTES: usize = 4 * 1024 * 1024;
 
 /// One entry with its value bytes in the byte order of the stream it came from.
 #[derive(Clone, Debug, PartialEq)]
@@ -53,13 +60,22 @@ impl ExifDirs {
     }
 }
 
-fn fields(f: &File<'_>, ifd: &Ifd, keep: impl Fn(u16) -> bool) -> Vec<Field> {
-    ifd.entries
-        .iter()
-        .filter(|e| keep(e.tag) && !matches!(e.tag, TAG_EXIF_IFD | TAG_GPS_IFD | TAG_INTEROP_IFD))
-        .filter_map(|e| Some(Field { tag: e.tag, ty: e.ty, count: u32::try_from(e.count).ok()?, value: f.data(e)?.to_vec() }))
-        .take(MAX_FIELDS)
-        .collect()
+/// The entries of `ifd` that `keep` accepts, with their values copied. An entry's value only has
+/// to lie inside the file, so entries may overlap: `budget` is the number of value bytes that may
+/// still be copied (shared by all the directories of one stream), and an entry whose value does
+/// not fit in what is left is skipped, so later, smaller entries can still be kept.
+fn fields(f: &File<'_>, ifd: &Ifd, budget: &mut usize, keep: impl Fn(u16) -> bool) -> Vec<Field> {
+    let mut out = Vec::new();
+    for e in ifd.entries.iter().filter(|e| keep(e.tag) && !matches!(e.tag, TAG_EXIF_IFD | TAG_GPS_IFD | TAG_INTEROP_IFD)) {
+        if out.len() >= MAX_FIELDS {
+            break;
+        }
+        let (Ok(count), Some(value)) = (u32::try_from(e.count), f.data(e)) else { continue };
+        let Some(left) = budget.checked_sub(value.len()) else { continue };
+        *budget = left;
+        out.push(Field { tag: e.tag, ty: e.ty, count, value: value.to_vec() });
+    }
+    out
 }
 
 fn sub(f: &File<'_>, ifd: &Ifd, tag: u16) -> Option<Ifd> {
@@ -69,14 +85,24 @@ fn sub(f: &File<'_>, ifd: &Ifd, tag: u16) -> Option<Ifd> {
 
 /// The EXIF parts of the classic TIFF stream `b` (a TIFF file, or an EXIF block without its
 /// `Exif\0\0` prefix): IFD0's descriptive tags and the Exif and GPS directories.
+///
+/// The values copied add up to at most [`MAX_COPIED_BYTES`] and to at most `b.len()`: the values
+/// of a well-formed stream are distinct bytes of it, while a hostile one can have many entries
+/// point at the same bytes and so ask for far more than its size. Entries that do not fit in what
+/// is left are left out (the small descriptive directories come first, so a huge maker note
+/// cannot crowd out the GPS position).
 pub(crate) fn read(b: &[u8]) -> Option<ExifDirs> {
     let f = File::parse(b)?;
     if f.big {
         return None;
     }
     let ifd0 = f.ifd(f.first_ifd)?;
-    let dir = |tag: u16| sub(&f, &ifd0, tag).map(|d| fields(&f, &d, |_| true)).unwrap_or_default();
-    Some(ExifDirs { le: f.le, ifd0: fields(&f, &ifd0, |t| IFD0_TAGS.contains(&t)), exif: dir(TAG_EXIF_IFD), gps: dir(TAG_GPS_IFD) })
+    let mut budget = MAX_COPIED_BYTES.min(b.len());
+    let ifd0_fields = fields(&f, &ifd0, &mut budget, |t| IFD0_TAGS.contains(&t));
+    let mut dir = |tag: u16| sub(&f, &ifd0, tag).map(|d| fields(&f, &d, &mut budget, |_| true)).unwrap_or_default();
+    let gps = dir(TAG_GPS_IFD);
+    let exif = dir(TAG_EXIF_IFD);
+    Some(ExifDirs { le: f.le, ifd0: ifd0_fields, exif, gps })
 }
 
 /// Bytes per element whose order a byte-order change reverses: a RATIONAL is two LONGs.
diff --git a/crates/codecs/tests/tiff_exif.rs b/crates/codecs/tests/tiff_exif.rs
index 92e8c91df0..7e06a0e5b8 100644
--- a/crates/codecs/tests/tiff_exif.rs
+++ b/crates/codecs/tests/tiff_exif.rs
@@ -166,3 +166,97 @@ fn no_exif_is_written_without_embed_metadata() {
     let tiff = encode(&img, Format::Tiff, &EncodeOptions { embed_metadata: false, ..Default::default() }).unwrap();
     assert_eq!(decode(&tiff).unwrap().meta.exif, None);
 }
+
+// ---------------------------------------------------------------------------
+// Bounded copying: an entry's value only has to lie inside the file, so a hostile file can have
+// many entries point at the same bytes.
+// ---------------------------------------------------------------------------
+
+/// A valid 1x1 gray TIFF whose Exif directory has `entries` UNDEFINED entries of `count` bytes
+/// that all point at the same `count` bytes: the file is about `count` bytes long and asks to
+/// copy `entries * count`.
+fn overlapping_tiff(entries: usize, count: u32) -> Vec<u8> {
+    let entry = |tag: u16, ty: u16, count: u32, value: u32| {
+        [tag.to_le_bytes().to_vec(), ty.to_le_bytes().to_vec(), count.to_le_bytes().to_vec(), value.to_le_bytes().to_vec()].concat()
+    };
+    let at_exif = 8 + 2 + 12 * 10 + 4;
+    let data_at = at_exif + 2 + 12 * entries + 4;
+    let mut out = b"II".to_vec();
+    out.extend(42u16.to_le_bytes());
+    out.extend(8u32.to_le_bytes());
+    out.extend(10u16.to_le_bytes());
+    for (tag, ty, value) in
+        [(256, 3, 1), (257, 3, 1), (258, 3, 8), (259, 3, 1), (262, 3, 1), (273, 4, 0), (277, 3, 1), (278, 3, 1), (279, 4, 1), (34665, 4, at_exif as u32)]
+    {
+        out.extend(entry(tag, ty, 1, value));
+    }
+    out.extend(0u32.to_le_bytes());
+    out.extend((entries as u16).to_le_bytes());
+    for i in 0..entries {
+        out.extend(entry(i as u16 + 1, 7, count, data_at as u32));
+    }
+    out.extend(0u32.to_le_bytes());
+    out.extend(vec![0x5A; count as usize]);
+    out
+}
+
+#[test]
+fn overlapping_field_values_are_bounded() {
+    // About 62 KB on disk; copied entry by entry it would be 1,000 x 50,000 bytes.
+    let tiff = overlapping_tiff(1000, 50_000);
+    assert!(tiff.len() < 64 * 1024);
+    let img = decode(&tiff).expect("the image itself is fine");
+    assert_eq!(img.dimensions(), (1, 1));
+    let exif = img.meta.exif.expect("the first entries are kept");
+    assert!(exif.len() <= 2 * tiff.len(), "{} bytes of EXIF from a {} byte file", exif.len(), tiff.len());
+}
+
+#[test]
+fn overlapping_field_values_in_an_exif_block_are_bounded_on_export() {
+    // The same block as an image's EXIF: the writer reads it with the same code.
+    let block = overlapping_tiff(1000, 50_000);
+    let mut img = Image::from_raw(2, 2, ChannelLayout::Gray, SampleType::U8, vec![0; 4]).unwrap();
+    img.meta.exif = Some(block.clone());
+    let tiff = encode(&img, Format::Tiff, &EncodeOptions::default()).unwrap();
+    assert!(tiff.len() <= 2 * block.len(), "a {} byte block wrote a {} byte file", block.len(), tiff.len());
+}
+
+/// An EXIF block with a maker note of `len` bytes, an exposure time and a GPS latitude reference.
+fn block_with_maker_note(le: bool, len: usize) -> Vec<u8> {
+    let b = Block { le };
+    b.build(
+        vec![(271, 2, 4, b"Cam\0".to_vec())],
+        vec![(33434, 5, 1, b.rational(1, 125)), (37500, 7, len as u32, (0..len).map(|i| (i * 7) as u8).collect())],
+        vec![(1, 2, 2, b"N\0".to_vec())],
+    )
+}
+
+#[test]
+fn large_maker_notes_still_survive() {
+    // Nikon maker notes run from 100 KB to nearly 1 MB.
+    for len in [200 * 1024, 1000 * 1024] {
+        let block = block_with_maker_note(true, len);
+        let mut img = Image::from_raw(4, 3, ChannelLayout::Rgb, SampleType::U8, vec![90; 36]).unwrap();
+        img.meta.exif = Some(block.clone());
+        let tiff = encode(&img, Format::Tiff, &EncodeOptions::default()).unwrap();
+        let back = decode(&tiff).unwrap().meta.exif.expect("EXIF read back");
+        let (ble, _, bexif, bgps) = dirs(&back);
+        let (ole, _, oexif, ogps) = dirs(&block);
+        assert_eq!(normalized(&bexif, ble), normalized(&oexif, ole), "{len} byte maker note");
+        assert_eq!(normalized(&bgps, ble), normalized(&ogps, ole));
+    }
+}
+
+#[test]
+fn a_field_beyond_the_cap_is_dropped_and_the_rest_kept() {
+    let block = block_with_maker_note(false, 6 * 1024 * 1024);
+    let mut img = Image::from_raw(2, 2, ChannelLayout::Gray, SampleType::U8, vec![0; 4]).unwrap();
+    img.meta.exif = Some(block);
+    let tiff = encode(&img, Format::Tiff, &EncodeOptions::default()).unwrap();
+    assert!(tiff.len() < 1024 * 1024, "{} bytes", tiff.len());
+    let back = decode(&tiff).unwrap().meta.exif.expect("EXIF read back");
+    let (_, ifd0, exif, gps) = dirs(&back);
+    assert_eq!(exif.iter().map(|e| e.0).collect::<Vec<_>>(), [33434], "the exposure time stays, the 6 MiB maker note goes");
+    assert_eq!(gps.iter().map(|e| e.0).collect::<Vec<_>>(), [1]);
+    assert_eq!(ifd0.iter().map(|e| e.0).collect::<Vec<_>>(), [271]);
+}
diff --git a/crates/engine/src/adjust_cmds.rs b/crates/engine/src/adjust_cmds.rs
index 7cc9cc656b..7e3b05b44c 100644
--- a/crates/engine/src/adjust_cmds.rs
+++ b/crates/engine/src/adjust_cmds.rs
@@ -270,6 +270,8 @@ pub(crate) fn adjust_as_smart_filter(s: &mut Session, kind: &str, label: &str, p
     if !smart {
         return Ok(false);
     }
+    // A pixel or full lock refuses the smart filter, as for `filter.*` on a smart object.
+    crate::commands::check_pixels_unlocked(&s.active().ok_or(EngineError::NoDocument)?.doc, id)?;
     // The recorded params are the command's own, minus the engine's private `__kind` key.
     let mut params = p.clone();
     if let Value::Object(m) = &mut params {
diff --git a/crates/engine/src/adjust_cmds/tests.rs b/crates/engine/src/adjust_cmds/tests.rs
index d831fbf448..1dc0c88656 100644
--- a/crates/engine/src/adjust_cmds/tests.rs
+++ b/crates/engine/src/adjust_cmds/tests.rs
@@ -479,6 +479,26 @@ fn adjustment_smart_filters_take_a_selection_as_their_mask() {
     assert_eq!(at(&now, 40, 16), at(&original, 40, 16), "outside the mask the composite is unchanged");
 }
 
+/// #5655: as for `filter.*` smart filters, a pixel or full lock refuses an adjustment smart
+/// filter, leaving the layer and the history as they were.
+#[test]
+fn locked_smart_objects_refuse_adjustment_smart_filters() {
+    let adjustments =
+        [("image.adjustments.invert", json!({})), ("image.adjustments.shadowsHighlights", json!({"shadowAmount": 100, "blackClip": 0, "whiteClip": 0}))];
+    for lock in [json!({"all": true}), json!({"pixels": true})] {
+        for (cmd, p) in &adjustments {
+            let mut s = smart_session();
+            s.execute("layer.lockLayers", lock.clone()).unwrap();
+            let (steps, flat) = (s.active().unwrap().history.past_len(), flatten(&s));
+            let r = s.execute(cmd, p.clone());
+            assert!(r.is_err(), "{cmd} added a smart filter to a smart object locked with {lock}: {r:?}");
+            assert!(smart_filters_of(&s).is_empty(), "{cmd} {lock}: nothing recorded");
+            assert_eq!(s.active().unwrap().history.past_len(), steps, "{cmd} {lock}: no history step");
+            assert_eq!(flatten(&s), flat, "{cmd} {lock}: pixels untouched");
+        }
+    }
+}
+
 /// A wrong-typed value errors before anything is recorded (never a panic), and the adjustments
 /// that can't re-render from a source (Replace Color, Match Color) stay off a smart object.
 #[test]
diff --git a/crates/engine/src/artboard_cmds.rs b/crates/engine/src/artboard_cmds.rs
index 94abee7221..4bc4a829b2 100644
--- a/crates/engine/src/artboard_cmds.rs
+++ b/crates/engine/src/artboard_cmds.rs
@@ -9,7 +9,7 @@
 
 use photocraft_color::{Color, ColorMode, PixelFormat, SampleType};
 use photocraft_doc::{Artboard, ArtboardBackground, Document, Layer, LayerContent, LayerId, Size};
-use photocraft_geom::Rect;
+use photocraft_geom::{Affine, Rect};
 use photocraft_raster::Surface;
 use serde_json::{Value, json};
 
@@ -506,6 +506,9 @@ pub fn artboard_document(doc: &Document, id: LayerId) -> Result<Option<Document>
     one.layer_comps.clear();
     one.last_applied_comp = None;
     one.last_document_state = None;
+    // Paths, notes, slices and Count/Ruler marks move with the board. This also shifts
+    // `one.guides`, but they are rebuilt below from the source's, so nothing moves twice.
+    crate::canvas_geom::transform_doc_marks(&mut one, &Affine::translate(f64::from(dx), f64::from(dy)));
     let shift = |v: &[f64], o: i32, len: u32| v.iter().map(|g| g - f64::from(o)).filter(|g| *g > 0.0 && *g < f64::from(len)).collect::<Vec<_>>();
     one.guides.vertical = shift(&doc.guides.vertical, r.x0, r.width());
     one.guides.horizontal = shift(&doc.guides.horizontal, r.y0, r.height());
diff --git a/crates/engine/src/artboard_cmds/tests.rs b/crates/engine/src/artboard_cmds/tests.rs
index c7695f228e..f3053e21fd 100644
--- a/crates/engine/src/artboard_cmds/tests.rs
+++ b/crates/engine/src/artboard_cmds/tests.rs
@@ -331,6 +331,33 @@ fn export_rejects_a_board_too_far_from_the_origin() {
     assert_eq!(one.artboards()[0].2.rect, Rect::new(0, 0, 50, 50));
 }
 
+/// Artboards to Files moves paths, notes, slices and Count/Ruler marks with the board, like its
+/// layers and guides, so they land on the same pixels in the exported file.
+#[test]
+fn artboard_export_moves_paths_notes_slices_and_marks_with_the_board() {
+    use photocraft_doc::{CountGroup, NamedPath, Note, Path, Slice, Subpath};
+    let mut s = session(8);
+    s.execute("layer.new.artboard", json!({"x": 200, "y": 100, "width": 50, "height": 50})).unwrap();
+    s.edit("marks", |d, _| {
+        d.paths.push(NamedPath { name: "P".into(), path: Path::new(vec![Subpath::polygon(&[(210.0, 110.0), (240.0, 110.0), (240.0, 140.0)])]), psd_raw: None });
+        d.work_path = Some(Path::new(vec![Subpath::polygon(&[(205.0, 105.0), (215.0, 105.0), (215.0, 115.0)])]));
+        d.notes.push(Note { position: [220.0, 120.0], popup: [220.0, 120.0, 260.0, 160.0], ..Default::default() });
+        d.slices.list.push(Slice { id: 1, rect: Rect::new(210, 110, 230, 130), ..Default::default() });
+        d.measurement.count_groups.push(CountGroup { points: vec![[225.0, 125.0]], ..Default::default() });
+        Ok(())
+    })
+    .unwrap();
+    let one = artboard_document(doc(&s), doc(&s).artboards()[0].0).unwrap().unwrap();
+    let k = &one.paths[0].path.subpaths[0].knots[0].anchor;
+    assert_eq!((k.x, k.y), (10.0, 10.0));
+    let w = &one.work_path.as_ref().unwrap().subpaths[0].knots[0].anchor;
+    assert_eq!((w.x, w.y), (5.0, 5.0));
+    assert_eq!(one.notes[0].position, [20.0, 20.0]);
+    assert_eq!(one.notes[0].popup, [20.0, 20.0, 60.0, 60.0]);
+    assert_eq!(one.slices.list[0].rect, Rect::new(10, 10, 30, 30));
+    assert_eq!(one.measurement.count_groups[0].points, vec![[25.0, 25.0]]);
+}
+
 /// #1531: a board 40×40 at (10, 10) holding a red square at (10..30)², the artboard active.
 fn board_with_square(s: &mut Session) -> LayerId {
     add_square(s, Rect::new(10, 10, 30, 30), [1.0, 0.0, 0.0, 1.0]);
diff --git a/crates/engine/src/canvas_geom.rs b/crates/engine/src/canvas_geom.rs
index 0722c6bd10..76142f9a75 100644
--- a/crates/engine/src/canvas_geom.rs
+++ b/crates/engine/src/canvas_geom.rs
@@ -55,9 +55,15 @@ fn map_fill(a: &Affine, f: &mut Fill) {
     if let Fill::Gradient { angle, offset, .. } = f {
         *angle = map_angle(a, *angle);
         // The centre offset (a fraction of the frame) turns with the canvas: exact for 90° turns
-        // and flips, where the frame's sides swap with the axes.
+        // and flips, where the frame's sides swap with the axes. Scale (Image Size) resizes the
+        // frame too, so only each axis's direction applies.
+        let unit = |x: f64, y: f64| {
+            let n = x.hypot(y);
+            if n < EPS { (x, y) } else { (x / n, y / n) }
+        };
+        let ((m0, m1), (m2, m3)) = (unit(a.m[0], a.m[1]), unit(a.m[2], a.m[3]));
         let (ox, oy) = (f64::from(offset.0), f64::from(offset.1));
-        *offset = ((a.m[0] * ox + a.m[2] * oy) as f32, (a.m[1] * ox + a.m[3] * oy) as f32);
+        *offset = ((m0 * ox + m2 * oy) as f32, (m1 * ox + m3 * oy) as f32);
     }
 }
 
diff --git a/crates/engine/src/canvas_geom/tests.rs b/crates/engine/src/canvas_geom/tests.rs
index 804a18b665..f27d9756fd 100644
--- a/crates/engine/src/canvas_geom/tests.rs
+++ b/crates/engine/src/canvas_geom/tests.rs
@@ -188,6 +188,39 @@ fn gradient_fill_angle_follows_the_canvas() {
     assert_eq!(map_angle(&Turn::Ccw90.affine(10.0, 20.0), 0.0), 90.0);
 }
 
+/// The gradient fill's centre offset after `cmd`, as `gradient.fill.get` reports it (% of the frame).
+fn fill_offset_after(cmd: &str, p: serde_json::Value) -> (f64, f64) {
+    let mut s = Session::new();
+    s.execute("file.new", json!({"width": 100, "height": 100})).unwrap();
+    s.execute("gradient.fill.create", json!({"from": [10, 50], "to": [90, 50], "style": "radial"})).unwrap();
+    s.execute("gradient.fill.set", json!({"angle": 0, "offset": [25, 0]})).unwrap();
+    s.execute(cmd, p).unwrap();
+    let g = s.execute("gradient.fill.get", json!({})).unwrap();
+    (g["offset"][0].as_f64().unwrap(), g["offset"][1].as_f64().unwrap())
+}
+
+#[test]
+fn gradient_fill_offset_stays_a_fraction_of_the_frame() {
+    let near = |a: (f64, f64), b: (f64, f64)| (a.0 - b.0).abs() < 1e-3 && (a.1 - b.1).abs() < 1e-3;
+    // Image Size scales the frame, so the offset (a fraction of it) stays put.
+    for (w, h) in [(200, 200), (50, 50), (200, 50)] {
+        let o = fill_offset_after("image.imageSize", json!({"width": w, "height": h}));
+        assert!(near(o, (25.0, 0.0)), "{w}x{h}: {o:?}");
+    }
+    // Flips and 90° turns still mirror and turn it.
+    assert!(near(fill_offset_after("image.imageRotation.flipCanvasHorizontal", json!({})), (-25.0, 0.0)));
+    assert!(near(fill_offset_after("image.imageRotation.90cw", json!({})), (0.0, 25.0)));
+    assert!(near(fill_offset_after("image.imageRotation.180", json!({})), (-25.0, 0.0)));
+    // Non-uniform scale with a turn: only the axis swap applies.
+    let mut f = Fill::gradient(Vec::new(), 0.0, 1.0, photocraft_doc::GradientStyle::Linear, false);
+    if let Fill::Gradient { offset, .. } = &mut f {
+        *offset = (0.25, -0.1);
+    }
+    map_fill(&Affine { m: [0.0, 3.0, -0.5, 0.0, 7.0, 1.0] }, &mut f);
+    let Fill::Gradient { offset, .. } = f else { panic!("not a gradient") };
+    assert!((offset.0 - 0.1).abs() < 1e-6 && (offset.1 - 0.25).abs() < 1e-6, "{offset:?}");
+}
+
 fn type_and_shape_origin(d: &Document) -> ([f64; 6], [f64; 2]) {
     let mut t = None;
     let mut k = None;
diff --git a/crates/engine/src/edit_menu_cmds.rs b/crates/engine/src/edit_menu_cmds.rs
index f9fab33e37..0b2aad8854 100644
--- a/crates/engine/src/edit_menu_cmds.rs
+++ b/crates/engine/src/edit_menu_cmds.rs
@@ -721,6 +721,13 @@ fn content_aware_fill_as(s: &mut Session, p: &Value, cmd: &'static str, label: &
             let cancel = || ctx.cancelled();
             let plan = content_aware_plan_with(&doc, id, &p, cmd, &photocraft_raster::Interrupt::cancel_only(&cancel))?;
             let CafPlan { layer, rect, fmt, img, layer_px, cover, hole, source, opts, output, .. } = plan;
+            // Patches come only from the sampling area outside the fill area. With none (a
+            // Rectangular `margin` of 0, a Custom area inside the selection or off the canvas)
+            // the fill would be black (#6532), so refuse instead. The workspace's preview builds
+            // the same plan and may show an empty area while the Sampling Brush adds to it.
+            if !source.iter().any(|s| *s) {
+                return Err(bad(cmd, "nothing to sample from: the sampling area has no pixels outside the fill area"));
+            }
             let (w, h) = (rect.width() as usize, rect.height() as usize);
             let n = fmt.channels();
             // The fill changes only the fill area: keep the layer's pixels and the coverage over
diff --git a/crates/engine/src/edit_menu_cmds/tests.rs b/crates/engine/src/edit_menu_cmds/tests.rs
index 873061e462..7564cc53d1 100644
--- a/crates/engine/src/edit_menu_cmds/tests.rs
+++ b/crates/engine/src/edit_menu_cmds/tests.rs
@@ -137,10 +137,15 @@ fn blob_session(depth: u32) -> Session {
 fn content_aware_fill_huge_area_neither_panics_nor_wraps() {
     let mut s = blob_session(8);
     // `[1e30, 0, 1e30, 10]` overflowed the i32 additions in the area parser (a debug-build
-    // panic, a garbage sampling window in release); the additions saturate now, so this is
-    // simply a whole-canvas window.
-    let r = s.execute("edit.contentAwareFill", json!({"sampling": "custom", "area": [1e30, 0.0, 1e30, 10.0], "colorAdaptation": "none"})).unwrap();
-    assert!(r["filled"].as_u64().unwrap() > 100);
+    // panic, a garbage sampling window in release); the additions saturate now, so the area lies
+    // wholly right of the canvas: nothing to sample, which is an error, not a black fill (#6532).
+    let before = s.active().unwrap().doc.clone();
+    let past = s.active().unwrap().history.past_len();
+    let err = s.execute("edit.contentAwareFill", json!({"sampling": "custom", "area": [1e30, 0.0, 1e30, 10.0], "colorAdaptation": "none"})).unwrap_err();
+    assert!(err.to_string().contains("nothing to sample from"), "{err}");
+    let st = s.active().unwrap();
+    assert!(std::sync::Arc::ptr_eq(&before, &st.doc), "the document changed");
+    assert_eq!(st.history.past_len(), past, "a history step was recorded");
     // A malformed area names the problem instead of silently falling back.
     for area in [json!([0.0, 0.0, null, 10.0]), json!([0.0, 0.0, 10.0]), json!("nope")] {
         let err = s.execute("edit.contentAwareFill", json!({"sampling": "custom", "area": area})).unwrap_err();
@@ -344,6 +349,23 @@ fn content_aware_fill_takes_the_workspace_edits() {
     assert!(r["filled"].as_u64().unwrap() > 2800);
 }
 
+/// #6532: a sampling area with no pixels outside the fill area is refused instead of filling it
+/// black, and leaves the document untouched; any margin past the selection fills.
+#[test]
+fn content_aware_fill_with_nothing_to_sample_is_refused() {
+    let mut s = blob_session(8);
+    let before = px(&s, 30, 22);
+    let revision = s.active().unwrap().revision;
+    for p in [json!({"sampling": "rectangular", "margin": 0}), json!({"sampling": "custom", "area": [28, 18, 4, 4]})] {
+        let e = s.execute("edit.contentAwareFill", p.clone()).unwrap_err().to_string();
+        assert!(e.contains("nothing to sample from"), "{p}: {e}");
+        assert_eq!(px(&s, 30, 22), before, "{p}: nothing was filled");
+        assert_eq!(s.active().unwrap().revision, revision, "{p}: no history step");
+    }
+    s.execute("edit.contentAwareFill", json!({"sampling": "rectangular", "margin": 1})).unwrap();
+    assert_ne!(px(&s, 30, 22), before, "the red blob is filled from around the selection");
+}
+
 #[test]
 fn content_aware_fill_outputs_and_sampling() {
     let mut s = blob_session(8);
diff --git a/crates/engine/src/presets/mod.rs b/crates/engine/src/presets/mod.rs
index 81382b418a..e5c3415f7d 100644
--- a/crates/engine/src/presets/mod.rs
+++ b/crates/engine/src/presets/mod.rs
@@ -362,6 +362,9 @@ pub(crate) fn edit_groups<T: Named>(groups: &mut Vec<Group<T>>, action: &str, p:
             let g = req_str(p, "group", cmd)?;
             let to = req_str(p, "name", cmd)?.to_string();
             let i = groups.iter().position(|x| x.name == g).ok_or_else(|| bad(cmd, format!("no group \"{g}\"")))?;
+            if g != to && groups.iter().any(|x| x.name == to) {
+                return Err(bad(cmd, format!("a group named \"{to}\" already exists")));
+            }
             groups[i].name = to.clone();
             Ok(json!({"group": to}))
         }
diff --git a/crates/engine/src/presets/tests.rs b/crates/engine/src/presets/tests.rs
index 1cde39abe5..db719afb1d 100644
--- a/crates/engine/src/presets/tests.rs
+++ b/crates/engine/src/presets/tests.rs
@@ -317,6 +317,23 @@ fn gradient_new_rename_move_delete_groups() {
     assert!(s.execute("gradient.presets.edit", json!({"action": "explode"})).is_err());
 }
 
+#[test]
+fn gradient_rename_group_refuses_a_name_another_group_has() {
+    let mut s = Session::new();
+    s.execute("gradient.presets.edit", json!({"action": "newGroup", "name": "Pastels"})).unwrap();
+    let names = |s: &mut Session| -> Vec<Value> {
+        s.execute("gradient.presets.list", json!({})).unwrap()["groups"].as_array().unwrap().iter().map(|g| g["name"].clone()).collect()
+    };
+    let before = names(&mut s);
+    assert!(before.contains(&json!("Blues")));
+    let err = s.execute("gradient.presets.edit", json!({"action": "renameGroup", "group": "Pastels", "name": "Blues"})).unwrap_err();
+    assert!(err.to_string().contains("already exists"), "{err}");
+    assert_eq!(names(&mut s), before, "a refused rename leaves the groups unchanged");
+    // Renaming a group to its own name is fine.
+    s.execute("gradient.presets.edit", json!({"action": "renameGroup", "group": "Pastels", "name": "Pastels"})).unwrap();
+    assert_eq!(names(&mut s), before);
+}
+
 #[test]
 fn presets_persist_through_preferences_json() {
     let mut s = Session::new();
diff --git a/crates/engine/src/smart_cmds.rs b/crates/engine/src/smart_cmds.rs
index 1f1cde7987..3ca10083b9 100644
--- a/crates/engine/src/smart_cmds.rs
+++ b/crates/engine/src/smart_cmds.rs
@@ -1065,6 +1065,9 @@ fn delete_filter(s: &mut Session, p: &Value) -> Result<Value> {
     edit_filters(s, p, "Delete Smart Filter", |sm| {
         let i = filter_index("layer.smartFilter.delete", p, sm)?;
         sm.smart_filters.remove(i);
+        if sm.smart_filters.is_empty() {
+            sm.filter_mask = None;
+        }
         Ok(())
     })
 }
@@ -1134,6 +1137,9 @@ fn transfer_filters(s: &mut Session, p: &Value) -> Result<Value> {
                 match index {
                     Some(i) => {
                         src.smart_filters.remove(i);
+                        if src.smart_filters.is_empty() {
+                            src.filter_mask = None;
+                        }
                     }
                     None => {
                         src.smart_filters.clear();
diff --git a/crates/engine/src/smart_cmds/tests.rs b/crates/engine/src/smart_cmds/tests.rs
index 1caaff6ce2..51d8d007f7 100644
--- a/crates/engine/src/smart_cmds/tests.rs
+++ b/crates/engine/src/smart_cmds/tests.rs
@@ -330,6 +330,37 @@ fn selection_becomes_the_filter_mask() {
     assert!(!s.is_enabled("layer.smartFilter.deleteFilterMask"));
 }
 
+/// #5619: deleting (or dragging away) the last smart filter removes the filter mask with it, so
+/// the next filter takes the new selection instead of the old one.
+#[test]
+fn removing_the_last_filter_removes_its_filter_mask() {
+    let mut s = session(8);
+    paint(&mut s);
+    let original = flat(&s);
+    let a = convert(&mut s);
+    s.execute("select.rect", json!({"x": 0, "y": 0, "width": 16, "height": 48})).unwrap();
+    s.execute("filter.blur.gaussianBlur", json!({"radius": 3})).unwrap();
+    assert!(active_smart(&s).filter_mask.is_some());
+    s.execute("layer.smartFilter.delete", json!({})).unwrap();
+    assert!(active_smart(&s).filter_mask.is_none(), "the last filter takes its mask along");
+    s.execute("select.rect", json!({"x": 20, "y": 0, "width": 20, "height": 48})).unwrap();
+    s.execute("filter.blur.gaussianBlur", json!({"radius": 3})).unwrap();
+    let px = flat(&s);
+    let at = |v: &Vec<[f32; 4]>, x: i32, y: i32| v[(y * W + x) as usize];
+    assert_eq!(at(&px, 6, 20), at(&original, 6, 20), "the old selection is not filtered");
+    assert_ne!(at(&px, 30, 20), at(&original, 30, 20), "the new selection is filtered");
+
+    // Dragging the only filter to another smart object leaves no mask behind either.
+    s.execute("select.deselect", json!({})).unwrap();
+    s.execute("layer.new.layer", json!({})).unwrap();
+    paint(&mut s);
+    let b = convert(&mut s);
+    s.execute("layer.smartFilter.transfer", json!({"from": a, "to": b, "filter": 0})).unwrap();
+    let doc = &s.active().unwrap().doc;
+    let LayerContent::Smart(sm) = &doc.layer(LayerId(a)).unwrap().content else { panic!("not smart") };
+    assert!(sm.smart_filters.is_empty() && sm.filter_mask.is_none());
+}
+
 /// Scales `id` to 10 % around the origin and back, returning the composite.
 fn shrink_and_grow(s: &mut Session, id: u64) -> Vec<[f32; 4]> {
     s.execute("edit.transform", json!({"layer": id, "matrix": [0.1, 0, 0, 0.1, 0, 0]})).unwrap();
diff --git a/crates/engine/src/timeline_cmds.rs b/crates/engine/src/timeline_cmds.rs
index 9baa077608..716fc8b4c8 100644
--- a/crates/engine/src/timeline_cmds.rs
+++ b/crates/engine/src/timeline_cmds.rs
@@ -59,7 +59,7 @@ fn duration_param(cmd: &str, p: &Value) -> Result<Option<usize>> {
 }
 
 /// The optional `fps` param, rejected unless it's a finite number in `(0, MAX_FPS]` (#1009).
-fn fps_param(cmd: &str, p: &Value) -> Result<Option<f32>> {
+pub(crate) fn fps_param(cmd: &str, p: &Value) -> Result<Option<f32>> {
     let Some(v) = p.get("fps").filter(|v| !v.is_null()) else { return Ok(None) };
     v.as_f64()
         .filter(|f| f.is_finite() && *f > 0.0 && *f <= f64::from(MAX_FPS))
diff --git a/crates/engine/src/transform_cmds.rs b/crates/engine/src/transform_cmds.rs
index 2fafc222f7..2452e7443b 100644
--- a/crates/engine/src/transform_cmds.rs
+++ b/crates/engine/src/transform_cmds.rs
@@ -378,6 +378,9 @@ fn apply_transform(
     // With a selection only the selected pixels move, and so only the same region of a linked
     // mask (#205). Groups, type, shapes and smart objects move whole.
     let mask_sel = doc_sel.filter(|_| !moves_whole(l));
+    // The masks (and so a fill's frame) move, but a fill layer's cached render isn't warped:
+    // drop it, the fill re-renders from its model (as `transform_layer_geometry` does).
+    l.fill_cache = None;
     match &mut l.content {
         LayerContent::Group(g) => {
             for c in g.children.iter_mut() {
@@ -992,6 +995,57 @@ mod tests {
         assert!(!active_bounds(&s).is_empty());
     }
 
+    /// A gradient fill layer whose mask (a selection when it was made) frames the gradient over
+    /// 10..40, with the cached render a PSD import gives it: exactly the pixels the fill renders.
+    fn cached_gradient_fill() -> Session {
+        let mut s = session();
+        s.execute("select.rect", json!({"x": 10, "y": 10, "width": 30, "height": 30})).unwrap();
+        s.execute("layer.newFillLayer.gradient", json!({"from": "#ff0000", "to": "#0000ff", "angle": 0})).unwrap();
+        s.execute("select.deselect", json!({})).unwrap();
+        s.edit("cache", |doc, active| {
+            let (fmt, canvas) = (doc.pixel_format(), doc.bounds());
+            let l = doc.layer_mut(active.unwrap()).unwrap();
+            let LayerContent::Fill(f) = &l.content else { panic!("a fill layer") };
+            let buf = photocraft_compose::render_fill_content(l, f, canvas, &[]);
+            let mut surface = Surface::new(fmt);
+            let vals: Vec<f32> = buf.px.iter().flat_map(|p| photocraft_raster::from_rgba(&fmt, *p)).collect();
+            surface.write_region(canvas, &vals);
+            l.fill_cache = Some(photocraft_doc::FillCache { fill: f.clone(), surface });
+            Ok(())
+        })
+        .unwrap();
+        s
+    }
+
+    /// How far the composite is from the composite with the fill re-rendered from its model
+    /// (cache dropped): the largest channel difference.
+    fn off_from_fresh(s: &Session) -> f32 {
+        let st = s.active().unwrap();
+        let mut fresh: Document = (*st.doc).clone();
+        fresh.layer_mut(st.active_layer.unwrap()).unwrap().fill_cache = None;
+        let (a, b) = (photocraft_compose::render(&st.doc, st.doc.bounds()).px, photocraft_compose::render(&fresh, fresh.bounds()).px);
+        a.iter().zip(&b).flat_map(|(p, q)| p.iter().zip(q).map(|(x, y)| (x - y).abs())).fold(0.0, f32::max)
+    }
+
+    #[test]
+    fn transforming_a_fill_layer_drops_its_stale_cached_render() {
+        let mut s = cached_gradient_fill();
+        let off = off_from_fresh(&s);
+        assert!(off < 0.01, "the cache is the fill's own render: {off}");
+        // The mask (and so the gradient's frame) moves 50 px right and doubles in height.
+        s.execute("edit.transform", json!({"matrix": [1, 0, 0, 2, 50, 0]})).unwrap();
+        let off = off_from_fresh(&s);
+        assert!(off < 0.01, "the composite shows the fill laid out in its new frame, not the old render: {off}");
+    }
+
+    #[test]
+    fn warping_a_fill_layer_drops_its_stale_cached_render() {
+        let mut s = cached_gradient_fill();
+        s.execute("edit.transform.warp", json!({"style": "arc", "bend": 50})).unwrap();
+        let off = off_from_fresh(&s);
+        assert!(off < 0.01, "the composite shows the fill laid out in its new frame, not the old render: {off}");
+    }
+
     #[test]
     fn type_moves_with_the_move_command() {
         let mut s = session();
diff --git a/crates/engine/src/video_cmds.rs b/crates/engine/src/video_cmds.rs
index dcb0d9a39e..0d27d3c827 100644
--- a/crates/engine/src/video_cmds.rs
+++ b/crates/engine/src/video_cmds.rs
@@ -301,7 +301,7 @@ fn new_from_file(s: &mut Session, p: &Value) -> Result<Value> {
     let fmt = s.active().ok_or(EngineError::NoDocument)?.doc.pixel_format();
     let Footage { frames, fps: footage_fps } = load_frames(&path, fmt)?;
     // An explicit `fps` wins, then the rate the footage implies, then 30.
-    let fps = p.get("fps").and_then(Value::as_f64).map(|f| f as f32).or(footage_fps).unwrap_or(30.0);
+    let fps = crate::timeline_cmds::fps_param("layer.videoLayers.newVideoLayerFromFile", p)?.or(footage_fps).unwrap_or(30.0);
     let n = frames.len();
     let id = s.edit("New Video Layer from File", |doc, active| {
         store(doc);
@@ -341,10 +341,10 @@ fn replace_footage(s: &mut Session, p: &Value) -> Result<Value> {
 }
 
 fn interpret_footage(s: &mut Session, p: &Value) -> Result<Value> {
-    let fps = p.get("fps").and_then(Value::as_f64);
+    let fps = crate::timeline_cmds::fps_param("layer.videoLayers.interpretFootage", p)?;
     edit_video(s, "Interpret Footage", move |v, _| {
         if let Some(f) = fps {
-            v.fps = f as f32;
+            v.fps = f;
         }
         Ok(())
     })
diff --git a/crates/engine/src/video_cmds/tests.rs b/crates/engine/src/video_cmds/tests.rs
index d9d8e451e1..3cdda8adc0 100644
--- a/crates/engine/src/video_cmds/tests.rs
+++ b/crates/engine/src/video_cmds/tests.rs
@@ -363,6 +363,32 @@ fn a_still_gif_is_one_frame_at_the_default_rate() {
     assert_eq!(s.active().unwrap().doc.layer(id).unwrap().video.as_ref().unwrap().fps, 10.0);
 }
 
+/// Interpret Footage and New Video Layer from File reject an fps that isn't a finite number in
+/// `(0, MAX_FPS]` and keep the layer as it was (#5657). 1e39 used to become an infinite rate the
+/// next `.pcraft` save refused.
+#[test]
+fn an_invalid_frame_rate_is_an_error_and_changes_nothing() {
+    let mut s = session();
+    let id = LayerId(s.execute("layer.videoLayers.newBlankVideoLayer", json!({})).unwrap()["layer"].as_u64().unwrap());
+    let fps = |s: &Session| s.active().unwrap().doc.layer(id).unwrap().video.as_ref().unwrap().fps;
+    assert_eq!(fps(&s), 30.0);
+    for bad in [json!(0), json!(-1), json!(1e39), json!("x")] {
+        assert!(s.execute("layer.videoLayers.interpretFootage", json!({"fps": bad})).is_err(), "fps {bad}");
+        assert_eq!(fps(&s), 30.0, "fps {bad}");
+    }
+    s.execute("layer.videoLayers.interpretFootage", json!({"fps": 24})).unwrap();
+    assert_eq!(fps(&s), 24.0);
+
+    let dir = tmpdir("gifin-badfps");
+    let path = format!("{dir}/anim.gif");
+    write_gif(&path, 8, 8, &[([255, 0, 0], 10), ([0, 255, 0], 10)]);
+    let layers = s.active().unwrap().doc.layer_count();
+    for bad in [json!(0), json!(-1), json!(1e39), json!("x")] {
+        assert!(s.execute("layer.videoLayers.newVideoLayerFromFile", json!({"path": path, "fps": bad})).is_err(), "fps {bad}");
+        assert_eq!(s.active().unwrap().doc.layer_count(), layers, "fps {bad}");
+    }
+}
+
 #[test]
 fn video_frames_to_layers_takes_every_gif_frame() {
     let dir = tmpdir("gifin-ftl");
diff --git a/crates/engine/src/warp_cmds.rs b/crates/engine/src/warp_cmds.rs
index 5142b0a940..8e2ab3c4fd 100644
--- a/crates/engine/src/warp_cmds.rs
+++ b/crates/engine/src/warp_cmds.rs
@@ -121,6 +121,9 @@ fn warp_layer(doc_sel: Option<&Surface>, group: Locks, l: &mut Layer, w: &Warp,
     // A selection limits the linked mask exactly as it limits the pixels (#4175, as Free Transform
     // and Perspective Warp do, #3083); a layer that moves whole takes its whole mask along.
     let mask_sel = doc_sel.filter(|_| !crate::transform_cmds::moves_whole(l));
+    // The masks (and so a fill's frame) move, but a fill layer's cached render isn't warped:
+    // drop it, the fill re-renders from its model.
+    l.fill_cache = None;
     match &mut l.content {
         LayerContent::Group(g) => {
             for c in g.children.iter_mut() {
diff --git a/crates/paint/src/brush_tests.rs b/crates/paint/src/brush_tests.rs
index 17ce652d59..2365d5e586 100644
--- a/crates/paint/src/brush_tests.rs
+++ b/crates/paint/src/brush_tests.rs
@@ -907,6 +907,38 @@ fn smoothing_without_catch_up_stops_while_the_pointer_pauses() {
     assert_eq!(out.len(), n, "held still: the brush doesn't move");
 }
 
+#[test]
+fn a_smoothed_brush_keeps_the_pressure_of_where_it_is_when_the_pen_lifts() {
+    // #5713: a fast stroke at full pressure, lifted in the last sample. The brush trails far
+    // behind the pointer; it used to take the lift's pressure there, and the end catch-up drew
+    // a hairline from the trailing brush to the pointer.
+    let pts: Vec<StrokePoint> =
+        (0..=20).map(|i| StrokePoint { time: f64::from(i) * 4.0, ..StrokePoint::new(f64::from(i) * 10.0, 0.0, if i < 20 { 1.0 } else { 0.05 }) }).collect();
+    let out = smooth_points(&Smoothing { amount: 0.8, ..Default::default() }, 1.0, &pts);
+    let (last, rest) = out.split_last().unwrap();
+    assert_eq!((last.x, last.pressure), (200.0, 0.05), "the catch-up still ends at the pen's last sample");
+    let lifted = rest.last().unwrap();
+    assert!(lifted.x < 190.0, "the brush lags the pointer: {}", lifted.x);
+    for p in rest {
+        assert!(p.pressure > 0.5, "the trailing brush at x {} has pressure {}", p.x, p.pressure);
+    }
+}
+
+#[test]
+fn a_pulled_string_brush_takes_the_pose_along_the_string() {
+    let ps = Smoothing { amount: 0.2, pulled_string: true, catch_up_on_end: false, ..Default::default() };
+    let a = StrokePoint { rotation: 350.0, ..StrokePoint::new(0.0, 0.0, 1.0) };
+    let b = StrokePoint { rotation: 10.0, tilt_x: 40.0, ..StrokePoint::new(100.0, 0.0, 0.0) };
+    let out = smooth_points(&ps, 1.0, &[a, b]);
+    // The 20 px string leaves the brush 80 % of the way to the pointer.
+    let p = out.last().unwrap();
+    assert!((p.x - 80.0).abs() < 1e-4, "{}", p.x);
+    assert!((p.pressure - 0.2).abs() < 1e-4, "{}", p.pressure);
+    assert!((p.tilt_x - 32.0).abs() < 1e-3, "{}", p.tilt_x);
+    // Rotation the short way round: 350° + 80 % of 20°.
+    assert!((p.rotation - 6.0).abs() < 1e-3, "{}", p.rotation);
+}
+
 #[test]
 fn pose_overrides_stylus_values() {
     let b = BrushSettings {
diff --git a/crates/paint/src/dynamics.rs b/crates/paint/src/dynamics.rs
index 05a638a532..0c535cf89c 100644
--- a/crates/paint/src/dynamics.rs
+++ b/crates/paint/src/dynamics.rs
@@ -55,6 +55,27 @@ fn lerp_pt(a: &StrokePoint, b: &StrokePoint, f: f64) -> StrokePoint {
 // Smoothing
 // ---------------------------------------------------------------------------
 
+/// The smoothed brush moved `f` of the way from `brush` towards the pointer `p`. Its pose
+/// (pressure, tilt, rotation, wheel) moves with it, so the lagging brush paints with the pose the
+/// pen had along the way, not the pointer's newest one. Taking the pointer's pressure made a fast
+/// stroke's lift thin the brush while it still trailed far behind, and the end catch-up a hairline
+/// (#5713). Time is the pointer's.
+fn pull(brush: &StrokePoint, p: &StrokePoint, f: f64) -> StrokePoint {
+    let ff = f as f32;
+    // Barrel rotation takes the shorter way round.
+    let dr = (p.rotation - brush.rotation + 540.0).rem_euclid(360.0) - 180.0;
+    StrokePoint {
+        x: brush.x + (p.x - brush.x) * f,
+        y: brush.y + (p.y - brush.y) * f,
+        pressure: brush.pressure + (p.pressure - brush.pressure) * ff,
+        tilt_x: brush.tilt_x + (p.tilt_x - brush.tilt_x) * ff,
+        tilt_y: brush.tilt_y + (p.tilt_y - brush.tilt_y) * ff,
+        rotation: (brush.rotation + dr * ff).rem_euclid(360.0),
+        wheel: brush.wheel + (p.wheel - brush.wheel) * ff,
+        time: p.time,
+    }
+}
+
 /// Incremental stroke smoothing: exponential (with optional time-based catch-up) or pulled string.
 #[derive(Clone, Debug)]
 pub struct Smoother {
@@ -96,7 +117,7 @@ impl Smoother {
             let d = (dx * dx + dy * dy).sqrt();
             if d > len {
                 let k = (d - len) / d;
-                let np = StrokePoint { x: pos.x + dx * k, y: pos.y + dy * k, ..p };
+                let np = pull(&pos, &p, k);
                 self.pos = Some(np);
                 out.push(np);
             }
@@ -122,7 +143,7 @@ impl Smoother {
         };
         let mut cur = pos;
         for _ in 0..iters {
-            cur = StrokePoint { x: cur.x + (p.x - cur.x) * step, y: cur.y + (p.y - cur.y) * step, ..p };
+            cur = pull(&cur, &p, step);
             out.push(cur);
         }
         self.pos = Some(cur);
diff --git a/crates/ui-egui/src/menu_keys.rs b/crates/ui-egui/src/menu_keys.rs
index 83fe21a550..c1536d8ee6 100644
--- a/crates/ui-egui/src/menu_keys.rs
+++ b/crates/ui-egui/src/menu_keys.rs
@@ -218,7 +218,12 @@ impl Keys {
                     self.alt_down = false;
                     tap |= std::mem::take(&mut self.alt_tap);
                 }
-                Event::Key { pressed: true, .. } | Event::Text(_) | Event::PointerButton { pressed: true, .. } => self.alt_tap = false,
+                // Alt+wheel (zoom, brush size…) or Alt going to the desktop is no tap either.
+                Event::Key { pressed: true, .. }
+                | Event::Text(_)
+                | Event::PointerButton { pressed: true, .. }
+                | Event::MouseWheel { .. }
+                | Event::WindowFocused(false) => self.alt_tap = false,
                 _ => {}
             }
         }
diff --git a/crates/ui-egui/src/menu_keys_tests.rs b/crates/ui-egui/src/menu_keys_tests.rs
index 4954053578..0298cb470f 100644
--- a/crates/ui-egui/src/menu_keys_tests.rs
+++ b/crates/ui-egui/src/menu_keys_tests.rs
@@ -76,6 +76,37 @@ fn alt_focuses_the_bar_arrows_move_and_down_opens_the_lit_menu() {
     assert!(!is_open(&h.ctx) && Keys::current(&h.ctx).focus.is_none(), "Esc leaves the menu and the bar");
 }
 
+/// Alt+wheel zooms; letting go of Alt after it is no tap, so Space (the hand tool) can't then
+/// open File and run New….
+#[test]
+fn alt_with_a_wheel_scroll_or_a_lost_focus_is_no_tap() {
+    let mut h = bar();
+    h.key_down(egui::Key::AltLeft);
+    h.run_steps(2);
+    h.event_modifiers(
+        egui::Event::MouseWheel {
+            unit: egui::MouseWheelUnit::Line,
+            delta: egui::vec2(0.0, -1.0),
+            phase: egui::TouchPhase::Move,
+            modifiers: egui::Modifiers::ALT,
+        },
+        egui::Modifiers::ALT,
+    );
+    h.run_steps(2);
+    h.key_up(egui::Key::AltLeft);
+    h.run_steps(3);
+    assert_eq!(Keys::current(&h.ctx).focus, None, "Alt+scroll leaves the bar alone");
+    key(&mut h, egui::Key::Space);
+    assert!(!is_open(&h.ctx), "Space opens no menu");
+    h.key_down(egui::Key::AltLeft);
+    h.run_steps(2);
+    h.event(egui::Event::WindowFocused(false));
+    h.event(egui::Event::WindowFocused(true));
+    h.key_up(egui::Key::AltLeft);
+    h.run_steps(3);
+    assert_eq!(Keys::current(&h.ctx).focus, None, "Alt that went to the desktop leaves the bar alone");
+}
+
 #[test]
 fn a_second_alt_or_esc_or_a_click_takes_the_keyboard_off_the_bar() {
     let mut h = bar();