From f1ed042c84fedebc1eff91d00c9c58477e912edc Mon Sep 17 00:00:00 2001
From: WindSoilder <WindSoilder@outlook.com>
Date: Wed, 29 Dec 2021 17:21:20 +0800
Subject: [PATCH] Fix: when goto normal mode, only want to remove indentation
 if the line is blank with no text following (#1349)

* when opened new line contains other characters after current position, don't dedent

* abstract checking logic
---
 helix-term/src/commands.rs | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 139e7ceb..9d7d11eb 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -3776,26 +3776,30 @@ fn normal_mode(cx: &mut Context) {
 }
 
 fn try_restore_indent(doc: &mut Document, view_id: ViewId) {
-    let doc_changes = doc.changes().changes();
-    let text = doc.text().slice(..);
-    let pos = doc.selection(view_id).primary().cursor(text);
-    let mut can_restore_indent = false;
-
-    // Removes trailing whitespace if insert mode is exited after starting a blank new line.
     use helix_core::chars::char_is_whitespace;
     use helix_core::Operation;
-    if let [Operation::Retain(move_pos), Operation::Insert(ref inserted_str), Operation::Retain(_)] =
-        doc_changes
-    {
-        if move_pos + inserted_str.len32() as usize == pos
-            && inserted_str.starts_with('\n')
-            && inserted_str.chars().skip(1).all(char_is_whitespace)
+
+    fn inserted_a_new_blank_line(changes: &[Operation], pos: usize, line_end_pos: usize) -> bool {
+        if let [Operation::Retain(move_pos), Operation::Insert(ref inserted_str), Operation::Retain(_)] =
+            changes
         {
-            can_restore_indent = true;
+            move_pos + inserted_str.len32() as usize == pos
+                && inserted_str.starts_with('\n')
+                && inserted_str.chars().skip(1).all(char_is_whitespace)
+                && pos == line_end_pos // ensure no characters exists after current position
+        } else {
+            false
         }
     }
 
-    if can_restore_indent {
+    let doc_changes = doc.changes().changes();
+    let text = doc.text().slice(..);
+    let range = doc.selection(view_id).primary();
+    let pos = range.cursor(text);
+    let line_end_pos = line_end_char_index(&text, range.cursor_line(text));
+
+    if inserted_a_new_blank_line(doc_changes, pos, line_end_pos) {
+        // Removes tailing whitespaces.
         let transaction =
             Transaction::change_by_selection(doc.text(), doc.selection(view_id), |range| {
                 let line_start_pos = text.line_to_char(range.cursor_line(text));