Merge titles say Confirm for code already on main; keepCode keeps main's annotations

A batch whose functions were all already on main (only confirmed now) was
titled "Decompile N functions", while its diff showed only the batch's other
changes. When a split keeps pending code, annotations that are on main stay.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RNwtXPYqFu3oKaaXwYwNWW

src/server/merge.js

@@ -336,12 +336,15 @@ export class Merger {
       batch.id,
     ).map((r) => r.name);
     const identicalCount = results.filter((r) => !r.peerConfirmed).length;
-    const title =
-      results.length === 1
-        ? `Decompile ${results[0].id}${results[0].name ? ` (${results[0].name})` : ''}`
-        : `Decompile ${results.length} functions in ${[...new Set(Object.keys(files))].slice(0, 2).join(', ')}${Object.keys(files).length > 2 ? ', ...' : ''}`;
     const head = this.repo.head();
     const change = (id) => this.codeChange(id, merged.files, head);
+    // Code that was already on main and is only confirmed now (often ported before the migration)
+    // is not a decompilation; the diff then shows only what else the batch changed.
+    const verb = results.every((r) => change(r.id) === ' (already on main)') ? 'Confirm' : 'Decompile';
+    const title =
+      results.length === 1
+        ? `${verb} ${results[0].id}${results[0].name ? ` (${results[0].name})` : ''}`
+        : `${verb} ${results.length} functions in ${[...new Set(Object.keys(files))].slice(0, 2).join(', ')}${Object.keys(files).length > 2 ? ', ...' : ''}`;
     const lines = results.map((r) => `- ${r.id}${r.name ? ` ${r.name}` : ''}: ${r.peerConfirmed ? 'logic confirmed by peer review' : 'byte-identical'}${change(r.id)}`);
     const message =
       `${title}\n\nBatch #${batch.id} by ${author}: ${identicalCount} byte-identical, ${results.length - identicalCount} confirmed by peer review.\n\n${lines.join('\n')}\n` +

src/server/split.js

@@ -94,7 +94,11 @@ export function withoutFunctions(files, ids, baseText, { keepCode = false } = {}
       continue;
     }
     if (keepCode) {
-      const drop = mine.flatMap((r) => r.ids.filter((id) => pending.has(id)).map((id) => r.lines.get(id))).sort((a, b) => b - a);
+      // Annotations already on main stay (the function keeps being measured there); only the ones
+      // the submission added are taken out.
+      const base = baseText(file);
+      const onMain = new Set(base === null ? [] : [...(functionRegions(base) ?? new Map()).keys()]);
+      const drop = mine.flatMap((r) => r.ids.filter((id) => pending.has(id) && !onMain.has(id)).map((id) => r.lines.get(id))).sort((a, b) => b - a);
       const lines = text.split('\n');
       for (const i of drop) lines.splice(i, 1);
       out[file] = lines.join('\n');

test/split.test.js

@@ -54,3 +54,9 @@ test('keepCode keeps the pending code and drops only its annotations', () => {
   const out = withoutFunctions({ 'a.cpp': text }, ['fn_00001'], () => 'int helper() {\n  return 1;\n}\n', { keepCode: true });
   assert.equal(out['a.cpp'], 'int helper(int x) {\n  return x;\n}\n\n// FUNCTION: fn_00002\nint user() {\n  return helper(2);\n}\n');
 });
+
+test('keepCode leaves annotations that are already on main', () => {
+  const text = '// FUNCTION: fn_00001\nint helper(int x) {\n  return x;\n}\n\n// FUNCTION: fn_00002\nint user() {\n  return helper(2);\n}\n';
+  const base = '// FUNCTION: fn_00001\nint helper() {\n  return 1;\n}\n';
+  assert.equal(withoutFunctions({ 'a.cpp': text }, ['fn_00001'], () => base, { keepCode: true })['a.cpp'], text);
+});