From 84e2a88c8ba7ae90dd3b8f6965512d8e6d5369ea Mon Sep 17 00:00:00 2001
From: gwenn <gtreguier@gmail.com>
Date: Sun, 4 Oct 2020 09:32:20 +0200
Subject: [PATCH] Disable CPR by default

---
 src/config.rs | 25 +++++++++++++++++++++++++
 src/lib.rs    |  2 +-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/config.rs b/src/config.rs
index 08aaa9882f..ff9881f331 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -28,6 +28,8 @@ pub struct Config {
     output_stream: OutputStreamType,
     /// Horizontal space taken by a tab.
     tab_stop: usize,
+    /// Check if cursor position is at leftmost before displaying prompt
+    check_cursor_position: bool,
 }
 
 impl Config {
@@ -145,6 +147,13 @@ impl Config {
     pub(crate) fn set_tab_stop(&mut self, tab_stop: usize) {
         self.tab_stop = tab_stop;
     }
+
+    /// Check if cursor position is at leftmost before displaying prompt.
+    ///
+    /// By default, we don't check.
+    pub fn check_cursor_position(&self) -> bool {
+        self.check_cursor_position
+    }
 }
 
 impl Default for Config {
@@ -162,6 +171,7 @@ impl Default for Config {
             color_mode: ColorMode::Enabled,
             output_stream: OutputStreamType::Stdout,
             tab_stop: 8,
+            check_cursor_position: false,
         }
     }
 }
@@ -357,6 +367,14 @@ impl Builder {
         self
     }
 
+    /// Check if cursor position is at leftmost before displaying prompt.
+    ///
+    /// By default, we don't check.
+    pub fn check_cursor_position(mut self, yes: bool) -> Self {
+        self.set_check_cursor_position(yes);
+        self
+    }
+
     /// Builds a `Config` with the settings specified so far.
     pub fn build(self) -> Config {
         self.p
@@ -451,4 +469,11 @@ pub trait Configurer {
     fn set_tab_stop(&mut self, tab_stop: usize) {
         self.config_mut().set_tab_stop(tab_stop);
     }
+
+    /// Check if cursor position is at leftmost before displaying prompt.
+    ///
+    /// By default, we don't check.
+    fn set_check_cursor_position(&mut self, yes: bool) {
+        self.config_mut().check_cursor_position = yes;
+    }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 018007663d..c4ed5bb48c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -439,7 +439,7 @@ fn readline_edit<H: Helper>(
     }
 
     let mut rdr = editor.term.create_reader(&editor.config)?;
-    if editor.term.is_output_tty() {
+    if editor.term.is_output_tty() && editor.config.check_cursor_position() {
         if let Err(e) = s.move_cursor_at_leftmost(&mut rdr) {
             if s.out.sigwinch() {
                 s.out.update_size();