From ce9774be530abfd692dafa7d84b4af15967b39d9 Mon Sep 17 00:00:00 2001
From: Antonio Scandurra <me@as-cii.com>
Date: Tue, 28 Mar 2023 09:50:03 +0200
Subject: [PATCH] Improve detection of common prefix in
 `text_for_active_completion`

---
 crates/editor/src/editor.rs | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/crates/editor/src/editor.rs b/crates/editor/src/editor.rs
index 6b47034674..9c1b0913aa 100644
--- a/crates/editor/src/editor.rs
+++ b/crates/editor/src/editor.rs
@@ -1034,19 +1034,16 @@ impl CopilotState {
         let completion = self.completions.get(self.active_completion_index)?;
         if self.position.excerpt_id == cursor.excerpt_id
             && self.position.buffer_id == cursor.buffer_id
-            && (cursor_offset == buffer.len() || buffer.contains_str_at(cursor_offset, "\n"))
         {
-            let completion_offset = buffer.summary_for_anchor(&Anchor {
+            let completion_offset: usize = buffer.summary_for_anchor(&Anchor {
                 excerpt_id: self.position.excerpt_id,
                 buffer_id: self.position.buffer_id,
                 text_anchor: completion.position,
             });
-            let common_prefix_len = cursor_offset.saturating_sub(completion_offset);
-            if common_prefix_len <= completion.text.len()
-                && buffer.contains_str_at(completion_offset, &completion.text[..common_prefix_len])
-            {
-                let suffix = &completion.text[common_prefix_len..];
-                if !suffix.is_empty() {
+            let prefix_len = cursor_offset.saturating_sub(completion_offset);
+            if completion_offset <= cursor_offset && prefix_len <= completion.text.len() {
+                let (prefix, suffix) = completion.text.split_at(prefix_len);
+                if buffer.contains_str_at(completion_offset, prefix) && !suffix.is_empty() {
                     return Some(suffix);
                 }
             }
@@ -2867,8 +2864,8 @@ impl Editor {
             .text_for_active_completion(self.copilot_state.position, &snapshot)
             .map(|text| text.to_string())
         {
-            self.copilot_state = Default::default();
             self.insert(&text, cx);
+            self.clear_copilot_suggestions(cx);
             true
         } else {
             false