From d83d5af2b571e5dc2c5c622277096a91c04ca7eb Mon Sep 17 00:00:00 2001
From: Kirill Chibisov <contact@kchibisov.com>
Date: Tue, 14 Nov 2023 23:17:59 +0400
Subject: [PATCH] Fix Vi cursor not being dirty when scrolling

---
 CHANGELOG.md           |  1 +
 alacritty/src/event.rs | 17 +++++++++-----
 alacritty/src/input.rs | 50 +++++++++++++++++++-----------------------
 3 files changed, 36 insertions(+), 32 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 48a65132..7546f001 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -70,6 +70,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Crash when leaving search after resize
 - Cursor being hidden after reaching cursor blinking timeout
 - Message bar content getting stuck after closing with multiple messages on Wayland
+- Vi cursor position not redrawn on PageUp/PageDown without scrollback
 
 ### Removed
 
diff --git a/alacritty/src/event.rs b/alacritty/src/event.rs
index f7fd044c..e6f77e8c 100644
--- a/alacritty/src/event.rs
+++ b/alacritty/src/event.rs
@@ -252,6 +252,7 @@ impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionCon
     fn scroll(&mut self, scroll: Scroll) {
         let old_offset = self.terminal.grid().display_offset() as i32;
 
+        let old_vi_cursor = self.terminal.vi_mode_cursor;
         self.terminal.scroll_display(scroll);
 
         let lines_changed = old_offset - self.terminal.grid().display_offset() as i32;
@@ -261,10 +262,10 @@ impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionCon
             self.search_state.display_offset_delta += lines_changed;
         }
 
+        let vi_mode = self.terminal.mode().contains(TermMode::VI);
+
         // Update selection.
-        if self.terminal.mode().contains(TermMode::VI)
-            && self.terminal.selection.as_ref().map_or(false, |s| !s.is_empty())
-        {
+        if vi_mode && self.terminal.selection.as_ref().map_or(false, |s| !s.is_empty()) {
             self.update_selection(self.terminal.vi_mode_cursor.point, Side::Right);
         } else if self.mouse.left_button_state == ElementState::Pressed
             || self.mouse.right_button_state == ElementState::Pressed
@@ -274,8 +275,14 @@ impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionCon
             self.update_selection(point, self.mouse.cell_side);
         }
 
-        // Update dirty if actually scrolled or we're in the Vi mode.
-        *self.dirty |= lines_changed != 0;
+        // Scrolling inside Vi mode moves the cursor, so start typing.
+        if vi_mode {
+            self.on_typing_start();
+        }
+
+        // Update dirty if actually scrolled or moved Vi cursor in Vi mode.
+        *self.dirty |=
+            lines_changed != 0 || (vi_mode && old_vi_cursor != self.terminal.vi_mode_cursor);
     }
 
     // Copy text selection.
diff --git a/alacritty/src/input.rs b/alacritty/src/input.rs
index 3c11c435..2c853488 100644
--- a/alacritty/src/input.rs
+++ b/alacritty/src/input.rs
@@ -328,37 +328,33 @@ impl<T: EventListener> Execute<T> for Action {
             Action::IncreaseFontSize => ctx.change_font_size(FONT_SIZE_STEP),
             Action::DecreaseFontSize => ctx.change_font_size(FONT_SIZE_STEP * -1.),
             Action::ResetFontSize => ctx.reset_font_size(),
-            Action::ScrollPageUp => {
+            Action::ScrollPageUp
+            | Action::ScrollPageDown
+            | Action::ScrollHalfPageUp
+            | Action::ScrollHalfPageDown => {
                 // Move vi mode cursor.
                 let term = ctx.terminal_mut();
-                let scroll_lines = term.screen_lines() as i32;
-                term.vi_mode_cursor = term.vi_mode_cursor.scroll(term, scroll_lines);
+                let (scroll, amount) = match self {
+                    Action::ScrollPageUp => (Scroll::PageUp, term.screen_lines() as i32),
+                    Action::ScrollPageDown => (Scroll::PageDown, -(term.screen_lines() as i32)),
+                    Action::ScrollHalfPageUp => {
+                        let amount = term.screen_lines() as i32 / 2;
+                        (Scroll::Delta(amount), amount)
+                    },
+                    Action::ScrollHalfPageDown => {
+                        let amount = -(term.screen_lines() as i32 / 2);
+                        (Scroll::Delta(amount), amount)
+                    },
+                    _ => unreachable!(),
+                };
 
-                ctx.scroll(Scroll::PageUp);
-            },
-            Action::ScrollPageDown => {
-                // Move vi mode cursor.
-                let term = ctx.terminal_mut();
-                let scroll_lines = -(term.screen_lines() as i32);
-                term.vi_mode_cursor = term.vi_mode_cursor.scroll(term, scroll_lines);
+                let old_vi_cursor = term.vi_mode_cursor;
+                term.vi_mode_cursor = term.vi_mode_cursor.scroll(term, amount);
+                if old_vi_cursor != term.vi_mode_cursor {
+                    ctx.mark_dirty();
+                }
 
-                ctx.scroll(Scroll::PageDown);
-            },
-            Action::ScrollHalfPageUp => {
-                // Move vi mode cursor.
-                let term = ctx.terminal_mut();
-                let scroll_lines = term.screen_lines() as i32 / 2;
-                term.vi_mode_cursor = term.vi_mode_cursor.scroll(term, scroll_lines);
-
-                ctx.scroll(Scroll::Delta(scroll_lines));
-            },
-            Action::ScrollHalfPageDown => {
-                // Move vi mode cursor.
-                let term = ctx.terminal_mut();
-                let scroll_lines = -(term.screen_lines() as i32 / 2);
-                term.vi_mode_cursor = term.vi_mode_cursor.scroll(term, scroll_lines);
-
-                ctx.scroll(Scroll::Delta(scroll_lines));
+                ctx.scroll(scroll);
             },
             Action::ScrollLineUp => ctx.scroll(Scroll::Delta(1)),
             Action::ScrollLineDown => ctx.scroll(Scroll::Delta(-1)),