From 0e5b42164628e5d25044cb5fd9592f7222701d6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Sat, 15 May 2021 10:26:41 +0900
Subject: [PATCH] When calculating a new selection, we need to take newly
 inserted text into account.

---
 helix-core/src/auto_pairs.rs | 24 ++++++++++++++++++++----
 helix-term/src/commands.rs   | 19 +++++++++++++------
 2 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/helix-core/src/auto_pairs.rs b/helix-core/src/auto_pairs.rs
index ffd16dafa..a04b0d3e9 100644
--- a/helix-core/src/auto_pairs.rs
+++ b/helix-core/src/auto_pairs.rs
@@ -65,14 +65,20 @@ fn handle_open(
 ) -> Transaction {
     let mut ranges = SmallVec::with_capacity(selection.len());
 
+    let mut offs = 0;
+
     let mut transaction = Transaction::change_by_selection(doc, selection, |range| {
         let pos = range.head;
         let next = next_char(doc, pos);
 
-        let head = pos + open.len_utf8();
+        let head = pos + offs + open.len_utf8();
         // if selection, retain anchor, if cursor, move over
         ranges.push(Range::new(
-            if range.is_empty() { head } else { range.anchor },
+            if range.is_empty() {
+                head
+            } else {
+                range.anchor + offs
+            },
             head,
         ));
 
@@ -88,6 +94,8 @@ fn handle_open(
                 pair.push_char(open);
                 pair.push_char(close);
 
+                offs += 2;
+
                 (pos, pos, Some(pair))
             }
         }
@@ -99,14 +107,20 @@ fn handle_open(
 fn handle_close(doc: &Rope, selection: &Selection, _open: char, close: char) -> Transaction {
     let mut ranges = SmallVec::with_capacity(selection.len());
 
+    let mut offs = 0;
+
     let mut transaction = Transaction::change_by_selection(doc, selection, |range| {
         let pos = range.head;
         let next = next_char(doc, pos);
 
-        let head = pos + close.len_utf8();
+        let head = pos + offs + close.len_utf8();
         // if selection, retain anchor, if cursor, move over
         ranges.push(Range::new(
-            if range.is_empty() { head } else { range.anchor },
+            if range.is_empty() {
+                head
+            } else {
+                range.anchor + offs
+            },
             head,
         ));
 
@@ -114,6 +128,8 @@ fn handle_close(doc: &Rope, selection: &Selection, _open: char, close: char) ->
             //  return transaction that moves past close
             (pos, pos, None) // no-op
         } else {
+            offs += close.len_utf8();
+
             // TODO: else return (use default handler that inserts close)
             (pos, pos, Some(Tendril::from_char(close)))
         }
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 104df72f9..5520c5afc 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -1644,6 +1644,9 @@ pub mod insert {
         let selection = doc.selection(view.id);
         let mut ranges = SmallVec::with_capacity(selection.len());
 
+        // TODO: this is annoying, but we need to do it to properly calculate pos after edits
+        let mut offs = 0;
+
         let mut transaction = Transaction::change_by_selection(contents, selection, |range| {
             let pos = range.head;
 
@@ -1667,10 +1670,14 @@ pub mod insert {
             text.push('\n');
             text.push_str(&indent);
 
-            let head = pos + text.len();
+            let head = pos + offs + text.len();
 
             ranges.push(Range::new(
-                if range.is_empty() { head } else { range.anchor },
+                if range.is_empty() {
+                    head
+                } else {
+                    range.anchor + offs
+                },
                 head,
             ));
 
@@ -1680,11 +1687,11 @@ pub mod insert {
                 let indent = doc.indent_unit().repeat(indent_level.saturating_sub(1));
                 text.push('\n');
                 text.push_str(&indent);
-
-                (pos, pos, Some(text.into()))
-            } else {
-                (pos, pos, Some(text.into()))
             }
+
+            offs += text.len();
+
+            (pos, pos, Some(text.into()))
         });
 
         transaction = transaction.with_selection(Selection::new(ranges, selection.primary_index()));