From 1c6b5581f01371a00dc7f6f6e1720ad8af61ec7a Mon Sep 17 00:00:00 2001
From: Nathan Vegdahl <cessen@cessen.com>
Date: Tue, 20 Jul 2021 11:58:56 -0700
Subject: [PATCH] Fix various bugs related to goto-end-of-line command.

This also fixes a bug with `Selection::normalize()`, that could
result in an out-of-bounds primary index.
---
 helix-core/src/selection.rs |  6 +++---
 helix-term/src/commands.rs  | 29 +++++++++++++++++++++++------
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs
index f1625f996..c08f504d3 100644
--- a/helix-core/src/selection.rs
+++ b/helix-core/src/selection.rs
@@ -357,14 +357,14 @@ impl Selection {
         let mut prev_i = 0;
         for i in 1..self.ranges.len() {
             if self.ranges[prev_i].overlaps(&self.ranges[i]) {
-                if i == self.primary_index {
-                    self.primary_index = prev_i;
-                }
                 self.ranges[prev_i] = self.ranges[prev_i].merge(self.ranges[i]);
             } else {
                 prev_i += 1;
                 self.ranges[prev_i] = self.ranges[i];
             }
+            if i == self.primary_index {
+                self.primary_index = prev_i;
+            }
         }
 
         self.ranges.truncate(prev_i + 1);
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 61c5096d0..a155e19eb 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -396,11 +396,19 @@ fn goto_line_end(cx: &mut Context) {
         view.id,
         doc.selection(view.id).clone().transform(|range| {
             let text = doc.text().slice(..);
-            let line = text.char_to_line(range.head);
 
-            let pos = line_end_char_index(&text, line);
-            let pos = graphemes::nth_prev_grapheme_boundary(text, pos, 1);
-            let pos = range.head.max(pos).max(text.line_to_char(line));
+            let head = if range.anchor < range.head {
+                graphemes::prev_grapheme_boundary(text, range.head)
+            } else {
+                range.head
+            };
+            let line = text.char_to_line(head);
+
+            let mut pos = line_end_char_index(&text, line);
+            if doc.mode != Mode::Select {
+                pos = graphemes::prev_grapheme_boundary(text, pos);
+            }
+            pos = head.max(pos).max(text.line_to_char(line));
 
             range.put(text, pos, doc.mode == Mode::Select)
         }),
@@ -414,9 +422,18 @@ fn goto_line_end_newline(cx: &mut Context) {
         view.id,
         doc.selection(view.id).clone().transform(|range| {
             let text = doc.text().slice(..);
-            let line = text.char_to_line(range.head);
 
-            let pos = line_end_char_index(&text, line);
+            let head = if range.anchor < range.head {
+                graphemes::prev_grapheme_boundary(text, range.head)
+            } else {
+                range.head
+            };
+            let line = text.char_to_line(head);
+
+            let mut pos = text.line_to_char((line + 1).min(text.len_lines()));
+            if doc.mode != Mode::Select {
+                pos = graphemes::prev_grapheme_boundary(text, pos);
+            }
             range.put(text, pos, doc.mode == Mode::Select)
         }),
     );