From 58c49f1c43d43078c53c95adf2e1663578eed26b Mon Sep 17 00:00:00 2001
From: Cole Miller <cole@zed.dev>
Date: Wed, 28 Jan 2026 12:25:38 -0500
Subject: [PATCH] git: Hide toggle split diff button behind flag (cherry-pick
 #47878) (#47884)

Release Notes:

- N/A

Co-authored-by: Jakub Konka <kubkon@jakubkonka.com>
---
 Cargo.lock                        |  1 +
 crates/editor/src/editor.rs       |  2 +-
 crates/editor/src/split.rs        |  2 +-
 crates/git_ui/Cargo.toml          |  1 +
 crates/git_ui/src/project_diff.rs | 45 ++++++++++++++++++-------------
 5 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 0ad2709c786c00d86ac568b8d0d31b9c4fe10af5..e5c859b24d343d4aae31271146f1d40743bacafd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7251,6 +7251,7 @@ dependencies = [
  "ctor",
  "db",
  "editor",
+ "feature_flags",
  "futures 0.3.31",
  "fuzzy",
  "git",
diff --git a/crates/editor/src/editor.rs b/crates/editor/src/editor.rs
index 6b691af3577ed49f677b7d1cc4c57db540c2718b..e4b3d1a6bb37f0080ba470c575fca2f82e8a6e31 100644
--- a/crates/editor/src/editor.rs
+++ b/crates/editor/src/editor.rs
@@ -72,7 +72,7 @@ pub use multi_buffer::{
     MultiBufferOffset, MultiBufferOffsetUtf16, MultiBufferSnapshot, PathKey, RowInfo, ToOffset,
     ToPoint,
 };
-pub use split::{SplittableEditor, ToggleLockedCursors, ToggleSplitDiff};
+pub use split::{SplitDiffFeatureFlag, SplittableEditor, ToggleLockedCursors, ToggleSplitDiff};
 pub use split_editor_view::SplitEditorView;
 pub use text::Bias;
 
diff --git a/crates/editor/src/split.rs b/crates/editor/src/split.rs
index a0d7251d6bbfdf1886fbddfa04a4771f1536aed8..1a8a6c626967321e910ca7ac4876c8dac0ceb2db 100644
--- a/crates/editor/src/split.rs
+++ b/crates/editor/src/split.rs
@@ -237,7 +237,7 @@ where
     })
 }
 
-struct SplitDiffFeatureFlag;
+pub struct SplitDiffFeatureFlag;
 
 impl FeatureFlag for SplitDiffFeatureFlag {
     const NAME: &'static str = "split-diff";
diff --git a/crates/git_ui/Cargo.toml b/crates/git_ui/Cargo.toml
index 504a168c5df42e7a9185d7de9c14012bfc65a08a..ae364fa55928f83f442ac700a6f4a22aece83724 100644
--- a/crates/git_ui/Cargo.toml
+++ b/crates/git_ui/Cargo.toml
@@ -27,6 +27,7 @@ command_palette_hooks.workspace = true
 component.workspace = true
 db.workspace = true
 editor.workspace = true
+feature_flags.workspace = true
 futures.workspace = true
 fuzzy.workspace = true
 git.workspace = true
diff --git a/crates/git_ui/src/project_diff.rs b/crates/git_ui/src/project_diff.rs
index 1b52202b47dc324334ab96c03c305392121ec12b..6e221589af292d1593ee5d2110620976c2312a30 100644
--- a/crates/git_ui/src/project_diff.rs
+++ b/crates/git_ui/src/project_diff.rs
@@ -8,11 +8,13 @@ use anyhow::{Context as _, Result, anyhow};
 use buffer_diff::{BufferDiff, DiffHunkSecondaryStatus};
 use collections::{HashMap, HashSet};
 use editor::{
-    Addon, Editor, EditorEvent, SelectionEffects, SplittableEditor, ToggleSplitDiff,
+    Addon, Editor, EditorEvent, SelectionEffects, SplitDiffFeatureFlag, SplittableEditor,
+    ToggleSplitDiff,
     actions::{GoToHunk, GoToPreviousHunk, SendReviewToAgent},
     multibuffer_context_lines,
     scroll::Autoscroll,
 };
+use feature_flags::FeatureFlagAppExt as _;
 use git::{
     Commit, StageAll, StageAndNext, ToggleStaged, UnstageAll, UnstageAndNext,
     repository::{Branch, RepoPath, Upstream, UpstreamTracking, UpstreamTrackingStatus},
@@ -1435,24 +1437,31 @@ impl Render for ProjectDiffToolbar {
                             )
                         },
                     )
-                    .child(
-                        Button::new(
-                            "toggle-split",
-                            if button_states.is_split {
-                                "Stacked View"
-                            } else {
-                                "Split View"
-                            },
+                    .map(|this| {
+                        if !cx.has_flag::<SplitDiffFeatureFlag>() {
+                            return this;
+                        }
+                        this.child(
+                            Button::new(
+                                "toggle-split",
+                                if button_states.is_split {
+                                    "Stacked View"
+                                } else {
+                                    "Split View"
+                                },
+                            )
+                            .tooltip(Tooltip::for_action_title_in(
+                                "Toggle Split View",
+                                &ToggleSplitDiff,
+                                &focus_handle,
+                            ))
+                            .on_click(cx.listener(
+                                |this, _, window, cx| {
+                                    this.dispatch_action(&ToggleSplitDiff, window, cx);
+                                },
+                            )),
                         )
-                        .tooltip(Tooltip::for_action_title_in(
-                            "Toggle Split View",
-                            &ToggleSplitDiff,
-                            &focus_handle,
-                        ))
-                        .on_click(cx.listener(|this, _, window, cx| {
-                            this.dispatch_action(&ToggleSplitDiff, window, cx);
-                        })),
-                    )
+                    })
                     .child(
                         Button::new("commit", "Commit")
                             .tooltip(Tooltip::for_action_title_in(