From e516961a094e59fd96087348714b60a8c3bebef1 Mon Sep 17 00:00:00 2001
From: Mohamed Boudra <boudra.moha@gmail.com>
Date: Fri, 6 Nov 2026 07:35:28 +0100
Subject: [PATCH] fix(diff): tolerate disappearing highlight sources

Source context is optional after Git has produced the patch. Missing worktree link metadata must preserve the existing hunk-based highlighting fallback instead of failing the revision.
---
 packages/server/src/server/diff/git.test.ts | 35 +++++++++++++++++++++
 packages/server/src/server/diff/sources.ts  | 11 ++++++-
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/packages/server/src/server/diff/git.test.ts b/packages/server/src/server/diff/git.test.ts
index ebea9003f7..d06fa2ae03 100644
--- a/packages/server/src/server/diff/git.test.ts
+++ b/packages/server/src/server/diff/git.test.ts
@@ -558,3 +558,38 @@ test.skipIf(process.platform === "win32")(
     }
   },
 );
+
+test("files removed between listing and highlighting retain their deletion patch", async () => {
+  const { encodeDiffFrame, decodeDiffFrame } =
+    await import("@getpaseo/protocol/binary-frames/index");
+  const cwd = await mkdtemp(join(tmpdir(), "diff-source-disappeared-"));
+  const git = (...args: string[]) => execFileSync("git", args, { cwd, encoding: "utf8" });
+  try {
+    git("init", "-b", "main");
+    git("config", "user.name", "Test");
+    git("config", "user.email", "test@example.com");
+    await writeFile(join(cwd, "a.ts"), "export const old = 1;\n");
+    git("add", ".");
+    git("-c", "commit.gpgsign=false", "commit", "-m", "base");
+    await writeFile(join(cwd, "a.ts"), "export const old = 2;\n");
+    const comparison = await listComparison({
+      cwd,
+      base: { kind: "rev", rev: "HEAD" },
+      head: { kind: "worktree" },
+    });
+    try {
+      expect(comparison.files[0].entry.change).toBe("modified");
+      await rm(join(cwd, "a.ts"));
+      const record = await readBody(comparison);
+      expect(record.body.hunks.flatMap((hunk) => hunk.lines)).toContainEqual(
+        expect.objectContaining({ type: "remove", content: "export const old = 1;" }),
+      );
+      const frame = { opcode: 0x41 as const, slot: 0, revision: 1, files: [record.body] };
+      expect(decodeDiffFrame(encodeDiffFrame(frame))).toEqual(frame);
+    } finally {
+      await comparison.close();
+    }
+  } finally {
+    await rm(cwd, { recursive: true, force: true });
+  }
+});
diff --git a/packages/server/src/server/diff/sources.ts b/packages/server/src/server/diff/sources.ts
index ab47ef2260..776303a9eb 100644
--- a/packages/server/src/server/diff/sources.ts
+++ b/packages/server/src/server/diff/sources.ts
@@ -40,7 +40,7 @@ export class HighlightSources {
       newFileContent = await this.content(contents, this.options.headSha, file.entry.path);
     } else if (file.entry.change !== "deleted") {
       const path = resolve(this.options.cwd, file.entry.path);
-      if ((await lstat(path)).isSymbolicLink()) newFileContent = await readlink(path);
+      newFileContent = await readWorktreeLink(path);
     }
     return { oldFileContent, newFileContent };
   }
@@ -65,3 +65,12 @@ export class HighlightSources {
     return content;
   }
 }
+
+async function readWorktreeLink(path: string): Promise<string | undefined> {
+  try {
+    if ((await lstat(path)).isSymbolicLink()) return await readlink(path);
+  } catch {
+    // Source context is optional; files can disappear after Git reads the patch.
+  }
+  return undefined;
+}