From f142f0ab3a912b1bb5019478715f152eb18f1a91 Mon Sep 17 00:00:00 2001
From: Yash Raj Pandey <yashpn62@gmail.com>
Date: Thu, 18 Jun 2026 11:50:54 -0400
Subject: [PATCH] fix(agent-edit): stop replace from orphaning a closing
 </span> on wrapped authored spans

expandRangeToIncludeFullyWrappedAuthoredSpan only expanded the edit range when
it exactly equalled a span's content bounds. When anchor resolution strips
authored spans it can return a range that includes the opening tag but stops at
the content edge (e.g. [openStart, contentEnd]), so the exact-equality check
missed and the trailing </span> was left behind as an unbalanced tag
(Hello <span ...>earth</span></span>!).

Expand whenever the resolved range covers the full span content and lies within
the span's outer bounds; a partial-content edit does not cover the full content,
so it keeps its wrapper. Fixes the failing edit-ops case (now 17/17).
---
 server/proof-span-strip.ts | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/server/proof-span-strip.ts b/server/proof-span-strip.ts
index 8ed5e199..5055a627 100644
--- a/server/proof-span-strip.ts
+++ b/server/proof-span-strip.ts
@@ -429,7 +429,16 @@ export function expandRangeToIncludeFullyWrappedAuthoredSpan(
   let nextEnd = end;
 
   for (const span of listAuthoredProofSpanBounds(markdown)) {
-    if (nextStart === span.contentStart && nextEnd === span.contentEnd) {
+    // Expand when the resolved range covers the span's entire inner content and
+    // sits within the span's outer tag bounds. Anchor resolution that strips
+    // authored spans can return a range that reaches the opening tag on one
+    // side but stops at the content edge on the other (e.g. [openStart,
+    // contentEnd]); requiring exact content-bound equality left the unmatched
+    // tag behind as an orphaned </span>. A partial-content edit does not cover
+    // the full content, so it is left untouched and keeps its wrapper.
+    const coversFullContent = nextStart <= span.contentStart && nextEnd >= span.contentEnd;
+    const withinSpanBounds = nextStart >= span.openStart && nextEnd <= span.closeEnd;
+    if (coversFullContent && withinSpanBounds) {
       nextStart = span.openStart;
       nextEnd = span.closeEnd;
       break;