From f8ab6299860deb9971689cbdfc597b07515ec87b Mon Sep 17 00:00:00 2001
From: Henrixounez <30901439+Henrixounez@users.noreply.github.com>
Date: Sun, 10 Nov 2019 17:33:21 +0100
Subject: [PATCH] readline: fix cursor position with prompt including ansi
 escape sequences

---
 vlib/readline/readline.v       |  1 +
 vlib/readline/readline_linux.v | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/vlib/readline/readline.v b/vlib/readline/readline.v
index b7f478e8ef..47a8912fce 100644
--- a/vlib/readline/readline.v
+++ b/vlib/readline/readline.v
@@ -36,6 +36,7 @@ mut:
   overwrite bool
   cursor_row_offset int
   prompt string
+  prompt_offset int
   previous_lines []ustring
   search_index int
   is_tty bool
diff --git a/vlib/readline/readline_linux.v b/vlib/readline/readline_linux.v
index 42b3541d29..759df0cf04 100644
--- a/vlib/readline/readline_linux.v
+++ b/vlib/readline/readline_linux.v
@@ -93,6 +93,7 @@ pub fn (r mut Readline) read_line_utf8(prompt string) ?ustring {
   r.cursor = 0
   r.prompt = prompt
   r.search_index = 0
+  r.prompt_offset = get_prompt_offset(prompt)
   if r.previous_lines.len <= 1 {
     r.previous_lines << ''.ustring()
     r.previous_lines << ''.ustring()
@@ -150,6 +151,19 @@ pub fn read_line(prompt string) ?string {
   return s
 }
 
+fn get_prompt_offset(prompt string) int {
+  mut len := 0
+
+  for i := 0; i < prompt.len; i++ {
+    if prompt[i] == `\e` {
+      for ;i < prompt.len && prompt[i] != `m`; i++ {}
+    } else {
+      len = len + 1
+    }
+  }
+  return prompt.len - len
+}
+
 fn (r Readline) analyse(c int) Action {
   match c {
     `\0`  { return .eof }
@@ -291,7 +305,7 @@ fn (r mut Readline) refresh_line() {
   if end_of_input[0] == 0 && end_of_input[1] > 0 {
     print('\n')
   }
-  shift_cursor(cursor_pos[0], - (end_of_input[1] - cursor_pos[1]))
+  shift_cursor(cursor_pos[0] - r.prompt_offset, - (end_of_input[1] - cursor_pos[1]))
   r.cursor_row_offset = cursor_pos[1]
 }