From 13dc977f39f6d7bf6af2a2c72f1e4a44143d9e13 Mon Sep 17 00:00:00 2001
From: Victor Vogel <satsdev@only21mil.xyz>
Date: Mon, 19 Oct 2026 16:57:38 -0500
Subject: [PATCH] fix(server): disable text conversion when measuring
 review-guide hunks

The review guide reads hunk line numbers from git diff to keep excerpts on
changed source lines. A configured textconv driver could rewrite that diff,
so excerpts of real changes were dropped. Pass --no-textconv as the review
diff already does.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../PullRequestReviewGuideService.test.ts     | 45 +++++++++++++++++++
 .../PullRequestReviewGuideService.ts          |  5 ++-
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/apps/server/src/pullRequest/PullRequestReviewGuideService.test.ts b/apps/server/src/pullRequest/PullRequestReviewGuideService.test.ts
index 66efa337ecd19..a8384605e60ae 100644
--- a/apps/server/src/pullRequest/PullRequestReviewGuideService.test.ts
+++ b/apps/server/src/pullRequest/PullRequestReviewGuideService.test.ts
@@ -706,6 +706,51 @@ it.layer(layerBase, { excludeTestServices: true })("PullRequestReviewGuideServic
     ),
   );
 
+  it.effect("keeps excerpts of source lines a configured diff driver would convert away", () =>
+    Effect.scoped(
+      Effect.gen(function* () {
+        const repositories = yield* makeRepositories;
+        const fs = yield* FileSystem.FileSystem;
+        yield* fs.writeFileString(
+          `${repositories.workspace}/.git/info/attributes`,
+          "feature.txt diff=blank\n",
+        );
+        yield* git(repositories.workspace, ["config", "diff.blank.textconv", "true"]);
+        const stored = yield* Deferred.make<void>();
+        const context = yield* Layer.build(
+          makeLayer({
+            ...repositories,
+            stored,
+            generate: () =>
+              Effect.succeed({
+                stops: [
+                  {
+                    title: "The feature",
+                    summary: "The change.",
+                    attention: null,
+                    excerpts: [{ path: "feature.txt", side: "new", start: 1, end: 3, caption: "" }],
+                    files: [],
+                    notes: [],
+                    questions: [],
+                  },
+                ],
+              }),
+          }),
+        );
+        const service = Context.get(
+          context,
+          PullRequestReviewGuideService.PullRequestReviewGuideService,
+        );
+        yield* service.generate(reference);
+        yield* Deferred.await(stored);
+        const result = yield* service.get(reference);
+        assert.deepStrictEqual(result.guide?.stops[0]?.excerpts, [
+          { path: "feature.txt", side: "new", start: 1, end: 3, caption: "" },
+        ]);
+      }),
+    ),
+  );
+
   it.effect("refuses generation when the verified remote disappeared despite a usable origin", () =>
     Effect.scoped(
       Effect.gen(function* () {
diff --git a/apps/server/src/pullRequest/PullRequestReviewGuideService.ts b/apps/server/src/pullRequest/PullRequestReviewGuideService.ts
index edd5dd2c72865..53799ae6cb0c6 100644
--- a/apps/server/src/pullRequest/PullRequestReviewGuideService.ts
+++ b/apps/server/src/pullRequest/PullRequestReviewGuideService.ts
@@ -351,7 +351,10 @@ const make = Effect.gen(function* () {
         })
         .pipe(Effect.map((result) => result.stdout));
     const [nameOnly, patch] = yield* Effect.all(
-      [diff(["--name-only", "-z"]), diff(["--unified=0", "--no-color", "--no-ext-diff"])],
+      [
+        diff(["--name-only", "-z"]),
+        diff(["--unified=0", "--no-color", "--no-ext-diff", "--no-textconv"]),
+      ],
       { concurrency: "unbounded" },
     );
     return parseReviewGuideChange(nameOnly, patch);