Integration: #2034 objects without a stacking order draw above the ones before them

crates/layout/src/lib.rs

@@ -3368,6 +3368,9 @@ fn place_objects(
     // first once all are placed, as Word stacks floating objects by `relativeHeight`, not by
     // their order in the paragraph. Inline objects and objects without one keep their order.
     let mut stack: Vec<(u32, Vec<Placed>, Vec<Placed>)> = Vec::new();
+    // The highest order so far: an object without one (inserted here) stacks above the objects
+    // before it, as the writer gives it the next order up on save.
+    let mut z_top = 0u32;
     let Some(fl) = pl.lines.get(l0) else { return (Vec::new(), Vec::new()) };
     // Objects left out of the layout (hidden, or deleted in the final text) aren't placed.
     let left_out = left_out_objects(ctx.doc, p, at.table_chr, ctx.opts.show_hidden, ctx.hide_deleted);
@@ -3458,7 +3461,13 @@ fn place_objects(
                 }
                 continue;
             }
-            stack.push((if floating { float.z } else { 0 }, behind, front));
+            let z = if floating && float.z > 0 {
+                z_top = z_top.max(float.z);
+                float.z
+            } else {
+                z_top
+            };
+            stack.push((z, behind, front));
         }
     }
     // Stable: equal orders (none given) keep the paragraph's order.

crates/layout/src/tests.rs

@@ -4053,6 +4053,14 @@ fn floats_are_drawn_in_their_stacking_order() {
     }
     let xs: Vec<f32> = shapes(&lay(&d).pages[0].items).iter().map(|r| r.x).collect();
     assert_eq!(xs, [200.0, 100.0], "behind the text: lowest first");
+    // One without an order, anchored after ordered ones, is drawn above them.
+    let mut d = Document::from_text("Text");
+    for (i, (x, z)) in [(100.0, 30), (200.0, 10), (300.0, 0)].into_iter().enumerate() {
+        let off = 4 + i * wordcraft_doc::para::OBJ.len_utf8();
+        d.insert_object(&Pos::body(0, off), at(x, z), &Default::default()).unwrap();
+    }
+    let xs: Vec<f32> = shapes(&lay(&d).pages[0].items).iter().map(|r| r.x).collect();
+    assert_eq!(xs, [200.0, 100.0, 300.0], "no order after ordered ones: drawn last");
 }
 
 #[test]