fix: cursor placement polish in footnote

Author: harbournick

packages/layout-engine/layout-bridge/src/index.ts

@@ -210,31 +210,16 @@ const logClickStage = (_level: 'log' | 'warn' | 'error', _stage: string, _payloa
   // No-op in production. Enable for debugging click-to-position mapping.
 };
 
-const readSelectionDebugEnabled = (): boolean => {
-  if (typeof globalThis === 'undefined') return false;
-  return (globalThis as { __sdSelectionDebug?: boolean }).__sdSelectionDebug === true;
-};
-
 const SELECTION_DEBUG_ENABLED = false;
 const logSelectionDebug = (payload: Record<string, unknown>): void => {
-  const enabled = SELECTION_DEBUG_ENABLED || readSelectionDebugEnabled();
-  if (!enabled) return;
+  if (!SELECTION_DEBUG_ENABLED) return;
   try {
     console.log('[SELECTION-DEBUG]', JSON.stringify(payload));
   } catch {
     console.log('[SELECTION-DEBUG]', payload);
   }
 };
 
-const pushSelectionDebugSnapshot = (payload: Record<string, unknown>): void => {
-  if (typeof globalThis === 'undefined') return;
-  const target = globalThis as { __sdSelectionDebugLog?: Record<string, unknown>[] };
-  if (!Array.isArray(target.__sdSelectionDebugLog)) {
-    target.__sdSelectionDebugLog = [];
-  }
-  target.__sdSelectionDebugLog.push(payload);
-};
-
 /**
  * Debug flag for DOM and geometry position mapping.
  * Set to true to enable detailed logging of click-to-position operations.
@@ -651,8 +636,7 @@ export function selectionToRects(
             pageIndex,
           });
 
-          const selectionDebugEnabled = SELECTION_DEBUG_ENABLED || readSelectionDebugEnabled();
-          if (selectionDebugEnabled) {
+          if (SELECTION_DEBUG_ENABLED) {
             const runs = block.runs.slice(line.fromRun, line.toRun + 1).map((run: Run, idx: number) => {
               const isAtomic =
                 'src' in run ||
@@ -673,7 +657,7 @@ export function selectionToRects(
               };
             });
 
-            const debugEntry = {
+            debugEntries.push({
               pageIndex,
               blockId: block.id,
               lineIndex: index,
@@ -715,9 +699,7 @@ export function selectionToRects(
               lineSpaceCount: (line as { spaceCount?: unknown }).spaceCount,
               lineNaturalWidth: (line as { naturalWidth?: unknown }).naturalWidth,
               lineMaxWidth: (line as { maxWidth?: unknown }).maxWidth,
-            };
-            debugEntries.push(debugEntry);
-            pushSelectionDebugSnapshot(debugEntry);
+            });
           }
         });
         return;

packages/layout-engine/layout-bridge/src/text-measurement.ts

@@ -20,6 +20,21 @@ let measurementCtx: CanvasRenderingContext2D | null = null;
 
 const TAB_CHAR_LENGTH = 1;
 
+const getRunCharacterLength = (run: Run | undefined): number => {
+  if (!run) return 0;
+  if (isTabRun(run)) return TAB_CHAR_LENGTH;
+  if (
+    'src' in run ||
+    run.kind === 'lineBreak' ||
+    run.kind === 'break' ||
+    run.kind === 'fieldAnnotation' ||
+    run.kind === 'math'
+  ) {
+    return 0;
+  }
+  return run.text?.length ?? 0;
+};
+
 /**
  * Characters considered as spaces for justify alignment calculations.
  * Only includes regular space (U+0020) and non-breaking space (U+00A0).
@@ -224,7 +239,8 @@ const getJustifyAdjustment = (
   // This ensures measurement matches rendering even when callers don't pass these flags.
   const lastRunIndex = block.runs.length - 1;
   const lastRun = block.runs[lastRunIndex];
-  const derivedIsLastLine = line.toRun >= lastRunIndex;
+  const lastRunLength = getRunCharacterLength(lastRun);
+  const derivedIsLastLine = line.toRun > lastRunIndex || (line.toRun === lastRunIndex && line.toChar >= lastRunLength);
   const derivedEndsWithLineBreak = lastRun ? lastRun.kind === 'lineBreak' : false;
   // Determine if justify should be applied using shared logic
   const shouldJustify = shouldApplyJustify({

packages/layout-engine/layout-bridge/test/text-measurement.test.ts

@@ -571,6 +571,25 @@ describe('text measurement utility', () => {
       expect(lastX).toBe(lastXNormal);
     });
 
+    it('applies justify spacing to wrapped non-last lines within a single text run', () => {
+      const block = createBlock([{ text: 'A B C D E F', fontFamily: 'Arial', fontSize: 16 }]);
+      (block as any).attrs = { alignment: 'justify' };
+
+      const line = baseLine({
+        fromRun: 0,
+        toRun: 0,
+        fromChar: 0,
+        toChar: 9, // Wrapped line consumes only part of the single text run
+        width: 90,
+        maxWidth: 120,
+      });
+
+      const xWithNaturalWidth = measureCharacterX(block, line, 7, 90);
+      const xWithSlack = measureCharacterX(block, line, 7, 120);
+
+      expect(xWithSlack).toBeGreaterThan(xWithNaturalWidth);
+    });
+
     it('skips justify spacing for manual tabs without explicit segments', () => {
       const trailingText = 'Item body';
       const tabWidth = 48;