From bf7dd1c369957851012df7f454b43a1c356ca379 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 7 Oct 2022 13:23:35 +0530
Subject: [PATCH] Fix multiline prompts

---
 tools/cmd/at/shell.go      |  3 ++-
 tools/tui/readline/api.go  |  5 +++++
 tools/tui/readline/draw.go | 14 +++++++-------
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/tools/cmd/at/shell.go b/tools/cmd/at/shell.go
index 183838d7a..4c997c9b7 100644
--- a/tools/cmd/at/shell.go
+++ b/tools/cmd/at/shell.go
@@ -56,8 +56,9 @@ func shell_loop(rl *readline.Readline, kill_if_signaled bool) (int, error) {
 				return nil
 			}
 			if err == readline.ErrAcceptInput {
-				if strings.HasSuffix(rl.TextBeforeCursor(), "\\") && strings.HasPrefix(rl.TextAfterCursor(), "\n") {
+				if strings.HasSuffix(rl.TextBeforeCursor(), "\\") && rl.CursorAtEndOfLine() {
 					rl.OnText("\n", false, false)
+					rl.Redraw()
 					return nil
 				}
 				return ErrExec
diff --git a/tools/tui/readline/api.go b/tools/tui/readline/api.go
index 1da1a76d6..5a0d62630 100644
--- a/tools/tui/readline/api.go
+++ b/tools/tui/readline/api.go
@@ -73,6 +73,7 @@ func New(loop *loop.Loop, r RlInit) *Readline {
 			ans.continuation_prompt = "> "
 		}
 	}
+	ans.continuation_prompt_len = wcswidth.Stringwidth(ans.continuation_prompt)
 	if ans.mark_prompts {
 		ans.prompt = PROMPT_MARK + "A" + ST + ans.prompt
 		ans.continuation_prompt = PROMPT_MARK + "A;k=s" + ST + ans.continuation_prompt
@@ -141,3 +142,7 @@ func (self *Readline) TextAfterCursor() string {
 func (self *Readline) AllText() string {
 	return self.all_text()
 }
+
+func (self *Readline) CursorAtEndOfLine() bool {
+	return self.cursor.X >= len(self.lines[self.cursor.Y])
+}
diff --git a/tools/tui/readline/draw.go b/tools/tui/readline/draw.go
index 47629e6ad..2a24a4660 100644
--- a/tools/tui/readline/draw.go
+++ b/tools/tui/readline/draw.go
@@ -18,9 +18,7 @@ func (self *Readline) write_line_with_prompt(line, prompt string, screen_width i
 
 func (self *Readline) move_cursor_to_text_position(pos, screen_width int) int {
 	num_of_lines := pos / screen_width
-	if num_of_lines > 0 {
-		self.loop.MoveCursorVertically(num_of_lines)
-	}
+	self.loop.MoveCursorVertically(num_of_lines)
 	self.loop.QueueWriteString("\r")
 	x := pos % screen_width
 	self.loop.MoveCursorHorizontally(x)
@@ -33,23 +31,25 @@ func (self *Readline) redraw() {
 	}
 	self.loop.QueueWriteString("\r")
 	self.loop.ClearToEndOfScreen()
-	y := 0
 	line_with_cursor := 0
 	screen_size, err := self.loop.ScreenSize()
 	if err != nil {
 		screen_size.WidthCells = 80
 		screen_size.HeightCells = 24
 	}
+	screen_width := int(screen_size.WidthCells)
+	y := 0
 	for i, line := range self.lines {
 		p := self.prompt
 		if i > 0 {
+			y += 1
+			self.loop.QueueWriteString("\r\n")
 			p = self.continuation_prompt
 		}
-		num_lines := self.write_line_with_prompt(line, p, int(screen_size.WidthCells))
 		if i == self.cursor.Y {
 			line_with_cursor = y
 		}
-		y += num_lines
+		y += self.write_line_with_prompt(line, p, screen_width)
 	}
 	self.loop.MoveCursorVertically(-y + line_with_cursor)
 	line := self.lines[self.cursor.Y]
@@ -57,6 +57,6 @@ func (self *Readline) redraw() {
 	if self.cursor.Y > 0 {
 		plen = self.continuation_prompt_len
 	}
-	line_with_cursor += self.move_cursor_to_text_position(plen+wcswidth.Stringwidth(line[:self.cursor.X]), int(screen_size.WidthCells))
+	line_with_cursor += self.move_cursor_to_text_position(plen+wcswidth.Stringwidth(line[:self.cursor.X]), screen_width)
 	self.cursor_y = line_with_cursor
 }