diff --git a/crates/editor/src/editor_tests.rs b/crates/editor/src/editor_tests.rs
index d9a2ff4d03..48c894e575 100644
--- a/crates/editor/src/editor_tests.rs
+++ b/crates/editor/src/editor_tests.rs
@@ -2685,6 +2685,65 @@ fn test_join_lines_with_multi_selection(cx: &mut TestAppContext) {
     });
 }
 
+#[gpui::test]
+async fn test_join_lines_with_git_diff_base(
+    executor: BackgroundExecutor,
+    cx: &mut gpui::TestAppContext,
+) {
+    init_test(cx, |_| {});
+
+    let mut cx = EditorTestContext::new(cx).await;
+
+    let diff_base = r#"
+        Line 0
+        Line 1
+        Line 2
+        Line 3
+        "#
+    .unindent();
+
+    cx.set_state(
+        &r#"
+        ˇLine 0
+        Line 1
+        Line 2
+        Line 3
+        "#
+        .unindent(),
+    );
+
+    cx.set_diff_base(Some(&diff_base));
+    executor.run_until_parked();
+
+    // Join lines
+    cx.update_editor(|editor, cx| {
+        editor.join_lines(&JoinLines, cx);
+    });
+    executor.run_until_parked();
+
+    cx.assert_editor_state(
+        &r#"
+        Line 0ˇ Line 1
+        Line 2
+        Line 3
+        "#
+        .unindent(),
+    );
+    // Join again
+    cx.update_editor(|editor, cx| {
+        editor.join_lines(&JoinLines, cx);
+    });
+    executor.run_until_parked();
+
+    cx.assert_editor_state(
+        &r#"
+        Line 0 Line 1ˇ Line 2
+        Line 3
+        "#
+        .unindent(),
+    );
+}
+
 #[gpui::test]
 async fn test_manipulate_lines_with_single_selection(cx: &mut TestAppContext) {
     init_test(cx, |_| {});
diff --git a/crates/git/src/diff.rs b/crates/git/src/diff.rs
index 38be750cf0..a8b14c2a49 100644
--- a/crates/git/src/diff.rs
+++ b/crates/git/src/diff.rs
@@ -130,6 +130,7 @@ impl BufferDiff {
 
             if end_point.column > 0 {
                 end_point.row += 1;
+                end_point.column = 0;
             }
 
             Some(DiffHunk {