From 5324f6a8c9a9b0985936a17cbe1d1b0bbe3ef535 Mon Sep 17 00:00:00 2001
From: Mateus Bento <mateusbentoa@gmail.com>
Date: Wed, 29 Jul 2026 13:09:22 -0300
Subject: [PATCH] fix(git): disable external diff for review diff previews

With diff.external configured, git diff delegates to that tool instead of
emitting a unified patch, so the Diff panel cannot parse it and falls back to
"Unsupported diff format. Showing raw patch." That is #927.

#927 was closed by #2553, which added --no-ext-diff to prepareCommitContext
and readRangeContext, and #2586 had already added it to the checkpoint diff.
Neither covered getReviewDiffPreview, which backs the Working tree and Branch
scopes, so those two still route through the external tool.

Adds --no-color --no-ext-diff --no-textconv to the three remaining call sites:
the tracked working-tree diff, the base...HEAD branch diff, and the --no-index
untracked file diffs.
---
 apps/server/src/vcs/GitVcsDriverCore.ts | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/apps/server/src/vcs/GitVcsDriverCore.ts b/apps/server/src/vcs/GitVcsDriverCore.ts
index f739c98da29..f6c163a557a 100644
--- a/apps/server/src/vcs/GitVcsDriverCore.ts
+++ b/apps/server/src/vcs/GitVcsDriverCore.ts
@@ -2001,7 +2001,18 @@ export const makeGitVcsDriverCore = Effect.fn("makeGitVcsDriverCore")(function*
         executeGit(
           "GitVcsDriver.readUntrackedReviewDiffs.diff",
           cwd,
-          ["diff", "--no-index", "--patch", "--minimal", "--", "/dev/null", relativePath],
+          [
+            "diff",
+            "--no-index",
+            "--patch",
+            "--no-color",
+            "--no-ext-diff",
+            "--no-textconv",
+            "--minimal",
+            "--",
+            "/dev/null",
+            relativePath,
+          ],
           {
             allowNonZeroExit: true,
             maxOutputBytes: REVIEW_UNTRACKED_DIFF_MAX_OUTPUT_BYTES,
@@ -2046,6 +2057,9 @@ export const makeGitVcsDriverCore = Effect.fn("makeGitVcsDriverCore")(function*
       [
         "diff",
         "--patch",
+        "--no-color",
+        "--no-ext-diff",
+        "--no-textconv",
         "--minimal",
         ...(input.ignoreWhitespace ? ["--ignore-all-space"] : []),
         "HEAD",
@@ -2079,6 +2093,9 @@ export const makeGitVcsDriverCore = Effect.fn("makeGitVcsDriverCore")(function*
             [
               "diff",
               "--patch",
+              "--no-color",
+              "--no-ext-diff",
+              "--no-textconv",
               "--minimal",
               ...(input.ignoreWhitespace ? ["--ignore-all-space"] : []),
               `${baseRef}...HEAD`,