use correct word-spacing when reshaping after break

man, this was hard to repro, probably would've rarely even happened

Author: chearon

src/layout-flow.ts

@@ -937,38 +937,12 @@ export class BlockContainerOfInlines extends BlockContainerBase {
   }
 
   getRunIndex(layout: Layout, ci: number) {
-    let l = this.treeStart, r = this.treeFinal;
-
-    while (true) {
-      const i = Math.floor((l + r) / 2);
-
-      if (layout.tree[i].isRun()) {
-        if (ci < layout.tree[i].textStart) {
-          r = i - 1;
-        } else if (ci >= layout.tree[i].textEnd) {
-          l = i + 1;
-        } else {
-          return i;
-        }
-      } else if (layout.tree[i].isInline()) {
-        if (ci < layout.tree[i].textStart) {
-          r = i - 1;
-        } else {
-          l = i + 1;
-        }
-      } else { // inline-block, float, or image. pick a side.
-        let ml = i;
-        let mr = i;
-
-        while (mr < r && !layout.tree[mr].isRun() && !layout.tree[mr].isInline()) mr++;
-        while (ml > l && !layout.tree[ml].isRun() && !layout.tree[ml].isInline()) ml--;
-
-        const item = layout.tree[mr];
-        if ((item.isRun() || item.isInline()) && ci < item.textStart) {
-          r = ml;
-        } else {
-          l = mr;
-        }
+    for (let i = this.treeStart + 2; i <= this.treeFinal; i++) {
+      const item = layout.tree[i];
+      if (item.isFormattingBox()) {
+        i = item.treeFinal;
+      } else if (item.isRun() && ci >= item.textStart && ci < item.textEnd) {
+        return i;
       }
     }
   }

src/layout-text.ts

@@ -2398,10 +2398,11 @@ function splitItem(
   ifc.block.items.splice(mark.itemIndex + 1, 0, right);
 
   if (needsReshape) {
-    const inlineIndex = ifc.block.getRunIndex(layout, left.offset);
     left.reshape(true);
     right.reshape(false);
     if (left.mayHaveModifiedWordSepGlyphs(layout)) {
+      const inlineIndex = ifc.block.getRunIndex(layout, left.offset);
+      if (inlineIndex === undefined) throw new Error('Assertion failed');
       postShapeAddWordSpacing(layout, ifc.block, ifc.block.items, inlineIndex, mark.itemIndex, mark.itemIndex + 2);
     }
   }

test/text.spec.js

@@ -1664,6 +1664,20 @@ describe('Word Spacing', function () {
     const block = this.get('#t');
     expect(block.items[0].measure().advance).to.equal(50);
   });
+
+  it('re-adds spaces when it needs to reshape', function () {
+    this.reflow(`
+      <div style="word-spacing: 10px; width: 260px;">
+        كلمة
+        <span style="display: inline-block; word-spacing: 100px;">كلمة كلمة</span>
+        كل&shy;مة
+      </div>
+    `);
+
+    /** @type import('../src/layout-flow.ts').BlockContainerOfInlines */
+    const [,, item] = this.get('div').items;
+    expect(item.measure().advance).to.equal(35.408);
+  });
 });
 
 describe('Vertical Align', function () {