Justification: Auto Leading stores the shown percent, and the current choice is no edit

The Auto Leading field shows whole percents, and it now stores the
whole percent it shows, so a typed 500.4% (shown as 500%) is accepted
as 500% instead of being refused. Picking the Single Word
Justification the paragraphs already have is no longer an edit, so OK
adds no undo step for it.

crates/ui-egui/src/dialogs.rs

@@ -7716,6 +7716,12 @@ const JUSTIFY_ROWS: [(&str, &str, (f64, f64)); 3] = [
 /// The allowed Auto Leading, in percent of the type size.
 const AUTO_LEADING_RANGE: (f64, f64) = (0.0, 500.0);
 
+/// The Auto Leading stored for a percent typed into its field: the whole percent the field shows.
+fn auto_leading_typed(pct: f64) -> f64 {
+    // Adding 0.0 turns a rounded -0 into 0.
+    (pct.round() + 0.0) / 100.0
+}
+
 /// The Single Word Justification choices: (attribute value, label).
 const SINGLE_WORD_CHOICES: [(&str, &str); 4] =
     [("left", "Align Left"), ("center", "Align Center"), ("right", "Align Right"), ("fullyJustified", "Full Justify")];
@@ -7941,7 +7947,7 @@ fn justification(lang: &str, ui: &mut egui::Ui, d: &mut Dialog, prefix: &str, cu
         crate::rtl::label(ui, crate::i18n::tr(lang, "Auto Leading:"));
         let auto = cur(d, "autoLeading").as_f64().map(|x| x * 100.0);
         if let Some(n) = ui.scope(|ui| crate::widgets::number(ui, &format!("ps{prefix}autoLeading"), auto, "%", 60.0, 0)).inner {
-            d.fields.insert(format!("{prefix}autoLeading"), json!(n / 100.0));
+            d.fields.insert(format!("{prefix}autoLeading"), json!(auto_leading_typed(n)));
         }
         ui.end_row();
         let single_label = crate::rtl::label(ui, crate::i18n::tr(lang, "Single Word Justification:"));
@@ -7954,7 +7960,13 @@ fn justification(lang: &str, ui: &mut egui::Ui, d: &mut Dialog, prefix: &str, cu
             .show_ui(ui, |ui| {
                 for (v, label) in SINGLE_WORD_CHOICES {
                     if ui.selectable_label(single.as_str() == Some(v), crate::rtl::widget(ui, crate::i18n::tr(lang, label))).clicked() {
-                        d.fields.insert(format!("{prefix}singleWordJustify"), json!(v));
+                        // The paragraphs' own choice is no edit, so OK adds no undo step for it.
+                        let key = format!("{prefix}singleWordJustify");
+                        if current["singleWordJustify"].as_str() == Some(v) {
+                            d.fields.remove(&key);
+                        } else {
+                            d.fields.insert(key, json!(v));
+                        }
                     }
                 }
             })

crates/ui-egui/src/dialogs/tests.rs

@@ -1156,8 +1156,15 @@ fn justification_dialog_sets_auto_leading_and_single_word_justification() {
     h.run_steps(3);
     assert!(h.query_by_label("Auto Leading:").is_some());
     assert!(h.query_by_label("Single Word Justification:").is_some());
-    // The dropdown shows the paragraph's Full Justify; pick Align Center.
-    h.get_by(|n| n.role() == egui::accesskit::Role::ComboBox && n.value().as_deref() == Some("Full Justify")).click();
+    use egui::accesskit::Role;
+    // The dropdown shows the paragraph's Full Justify. Picking Full Justify again is no edit.
+    h.get_by(|n| n.role() == Role::ComboBox && n.value().as_deref() == Some("Full Justify")).click();
+    h.run_steps(3);
+    h.get_by(|n| n.role() != Role::ComboBox && n.label().as_deref() == Some("Full Justify")).click();
+    h.run_steps(3);
+    assert!(!h.state().ui.dialog.as_ref().unwrap().fields.contains_key("singleWordJustify"), "the paragraph's own choice is no edit");
+    // Pick Align Center.
+    h.get_by(|n| n.role() == Role::ComboBox && n.value().as_deref() == Some("Full Justify")).click();
     h.run_steps(3);
     h.get_by_label("Align Center").click();
     h.run_steps(3);
@@ -1170,8 +1177,8 @@ fn justification_dialog_sets_auto_leading_and_single_word_justification() {
     let d = app.ui.dialog.clone().unwrap();
     let before = undo_steps(&app);
     let bad = [
-        ("autoLeading", json!(5.004)),
-        ("autoLeading", json!(-0.004)),
+        ("autoLeading", json!(5.01)),
+        ("autoLeading", json!(-0.01)),
         ("autoLeading", json!(f64::NAN)),
         ("singleWordJustify", json!("leftJustified")),
     ];
@@ -1183,6 +1190,15 @@ fn justification_dialog_sets_auto_leading_and_single_word_justification() {
     }
     assert_eq!(undo_steps(&app), before);
 
+    // A typed percent is stored as the whole percent the field shows, so 500.4% (shown as 500%)
+    // and -0.4% (shown as 0%) are accepted.
+    for (typed, stored) in [(500.4, 5.0), (-0.4, 0.0), (149.6, 1.5)] {
+        assert_eq!(auto_leading_typed(typed), stored, "{typed}%");
+        let mut probe = d.clone();
+        probe.fields.insert("autoLeading".into(), json!(auto_leading_typed(typed)));
+        assert_eq!(check_justification(&probe, "", &current), Ok(()), "{typed}%");
+    }
+
     app.ui.dialog = Some(d);
     app.ui.dialog.as_mut().unwrap().fields.insert("autoLeading".into(), json!(1.5));
     draw(&mut app, &ctx);