From 3a008101420fd7ba5db4cbef82f22b76d70f4222 Mon Sep 17 00:00:00 2001
From: Xin Zhao <zx0@mail.ustc.edu.cn>
Date: Fri, 20 Feb 2026 15:38:16 +0800
Subject: [PATCH] editor: Prevent comment extension on REPL separators (#48174)

Closes #47691

Release Notes:

- N/A *or* Added/Fixed/Improved ...
---
 crates/editor/src/editor.rs       | 31 ++++++++++++++++-----
 crates/editor/src/editor_tests.rs | 45 +++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+), 6 deletions(-)

diff --git a/crates/editor/src/editor.rs b/crates/editor/src/editor.rs
index cba09fb543dbb9d17d36ab173510cc368660b9ca..3fa52ed21e68ac432c2a3922c85ed40b61f7621d 100644
--- a/crates/editor/src/editor.rs
+++ b/crates/editor/src/editor.rs
@@ -25679,19 +25679,25 @@ fn comment_delimiter_for_newline(
     let comment_candidate = snapshot
         .chars_for_range(range.clone())
         .skip(num_of_whitespaces)
-        .take(max_len_of_delimiter)
+        .take(max_len_of_delimiter + 2)
         .collect::<String>();
-    let (delimiter, trimmed_len) = delimiters
+    let (delimiter, trimmed_len, is_repl) = delimiters
         .iter()
         .filter_map(|delimiter| {
             let prefix = delimiter.trim_end();
             if comment_candidate.starts_with(prefix) {
-                Some((delimiter, prefix.len()))
+                let is_repl = if let Some(stripped_comment) = comment_candidate.strip_prefix(prefix)
+                {
+                    stripped_comment.starts_with(" %%")
+                } else {
+                    false
+                };
+                Some((delimiter, prefix.len(), is_repl))
             } else {
                 None
             }
         })
-        .max_by_key(|(_, len)| *len)?;
+        .max_by_key(|(_, len, _)| *len)?;
 
     if let Some(BlockCommentConfig {
         start: block_start, ..
@@ -25700,7 +25706,7 @@ fn comment_delimiter_for_newline(
         let block_start_trimmed = block_start.trim_end();
         if block_start_trimmed.starts_with(delimiter.trim_end()) {
             let line_content = snapshot
-                .chars_for_range(range)
+                .chars_for_range(range.clone())
                 .skip(num_of_whitespaces)
                 .take(block_start_trimmed.len())
                 .collect::<String>();
@@ -25714,7 +25720,20 @@ fn comment_delimiter_for_newline(
     let cursor_is_placed_after_comment_marker =
         num_of_whitespaces + trimmed_len <= start_point.column as usize;
     if cursor_is_placed_after_comment_marker {
-        Some(delimiter.clone())
+        if !is_repl {
+            return Some(delimiter.clone());
+        }
+
+        let line_content_after_cursor: String = snapshot
+            .chars_for_range(range)
+            .skip(start_point.column as usize)
+            .collect();
+
+        if line_content_after_cursor.trim().is_empty() {
+            return None;
+        } else {
+            return Some(delimiter.clone());
+        }
     } else {
         None
     }
diff --git a/crates/editor/src/editor_tests.rs b/crates/editor/src/editor_tests.rs
index 18a29b2befc84a61d2345de8384c7ebe595df774..bc44038c05c7864966f1c9a012f171022134cdaa 100644
--- a/crates/editor/src/editor_tests.rs
+++ b/crates/editor/src/editor_tests.rs
@@ -3752,6 +3752,51 @@ async fn test_newline_comments_with_multiple_delimiters(cx: &mut TestAppContext)
     }
 }
 
+#[gpui::test]
+async fn test_newline_comments_repl_separators(cx: &mut TestAppContext) {
+    init_test(cx, |settings| {
+        settings.defaults.tab_size = NonZeroU32::new(4)
+    });
+    let language = Arc::new(Language::new(
+        LanguageConfig {
+            line_comments: vec!["# ".into()],
+            ..LanguageConfig::default()
+        },
+        None,
+    ));
+
+    {
+        let mut cx = EditorTestContext::new(cx).await;
+        cx.update_buffer(|buffer, cx| buffer.set_language(Some(language), cx));
+        cx.set_state(indoc! {"
+        # %%ˇ
+    "});
+        cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+        cx.assert_editor_state(indoc! {"
+        # %%
+        ˇ
+    "});
+
+        cx.set_state(indoc! {"
+            # %%%%%ˇ
+    "});
+        cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+        cx.assert_editor_state(indoc! {"
+            # %%%%%
+            ˇ
+    "});
+
+        cx.set_state(indoc! {"
+            # %ˇ%
+    "});
+        cx.update_editor(|e, window, cx| e.newline(&Newline, window, cx));
+        cx.assert_editor_state(indoc! {"
+            # %
+            # ˇ%
+    "});
+    }
+}
+
 #[gpui::test]
 async fn test_newline_documentation_comments(cx: &mut TestAppContext) {
     init_test(cx, |settings| {