Recall recent history index only on empty line and down key

src/edit.rs

@@ -636,6 +636,7 @@ impl<'out, 'prompt, H: Helper> State<'out, 'prompt, H> {
         if history.is_empty() {
             return Ok(());
         }
+        self.ctx.recall(!prev && self.line.is_empty());
         if self.ctx.history_index == history.len() {
             if prev {
                 // Save the current edited line before overwriting it
@@ -762,7 +763,7 @@ pub fn init_state<'out, H: Helper>(
         byte_buffer: [0; 4],
         changes: Changeset::new(),
         helper,
-        ctx: Context::new(history),
+        ctx: Context::new(history, None),
         hint: Some(Box::new("hint".to_owned())),
         highlight_char: false,
         forced_refresh: false,

src/hint.rs

@@ -95,7 +95,7 @@ mod test {
     #[test]
     pub fn empty_history() {
         let history = DefaultHistory::new();
-        let ctx = Context::new(&history);
+        let ctx = Context::new(&history, None);
         let hinter = HistoryHinter {};
         let hint = hinter.hint("test", 4, &ctx);
         assert_eq!(None, hint);

src/history.rs

@@ -172,7 +172,7 @@ pub trait History {
      */
 
     /// recently used index
-    fn recent_index(&self) -> Option<usize>;
+    fn recent_index(&mut self) -> Option<usize>;
     /// Update recently used index
     fn set_recent_index(&mut self, entry: Option<(usize, &str)>);
 }
@@ -427,8 +427,8 @@ impl History for MemHistory {
         }
     }
 
-    fn recent_index(&self) -> Option<usize> {
-        self.recent
+    fn recent_index(&mut self) -> Option<usize> {
+        self.recent.take()
     }
 
     fn set_recent_index(&mut self, entry: Option<(usize, &str)>) {
@@ -813,7 +813,7 @@ impl History for FileHistory {
         self.mem.starts_with(term, start, dir)
     }
 
-    fn recent_index(&self) -> Option<usize> {
+    fn recent_index(&mut self) -> Option<usize> {
         self.mem.recent_index()
     }
 

src/lib.rs

@@ -557,15 +557,17 @@ impl<'h, H: ?Sized + Helper> Helper for &'h H {}
 pub struct Context<'h> {
     history: &'h dyn History,
     history_index: usize,
+    recent_index: Option<usize>,
 }
 
 impl<'h> Context<'h> {
     /// Constructor. Visible for testing.
     #[must_use]
-    pub fn new(history: &'h dyn History) -> Self {
+    pub fn new(history: &'h dyn History, recent_index: Option<usize>) -> Self {
         Context {
             history,
-            history_index: history.recent_index().unwrap_or(history.len()),
+            history_index: history.len(),
+            recent_index,
         }
     }
 
@@ -580,6 +582,14 @@ impl<'h> Context<'h> {
     pub fn history_index(&self) -> usize {
         self.history_index
     }
+
+    pub(crate) fn recall(&mut self, next_and_empty: bool) {
+        if let Some(idx) = self.recent_index.take() {
+            if next_and_empty {
+                self.history_index = idx;
+            }
+        }
+    }
 }
 
 /// Line editor
@@ -694,7 +704,8 @@ impl<H: Helper, I: History> Editor<H, I> {
         let mut stdout = self.term.create_writer();
 
         self.kill_ring.reset(); // TODO recreate a new kill ring vs reset
-        let ctx = Context::new(&self.history);
+        let recent_index = self.history.recent_index();
+        let ctx = Context::new(&self.history, recent_index);
         let mut s = State::new(&mut stdout, prompt, self.helper.as_ref(), ctx);
 
         let mut input_state = InputState::new(&self.config, &self.custom_bindings);

src/sqlite_history.rs

@@ -411,7 +411,7 @@ PRAGMA incremental_vacuum;
         self.search_match(term, start, dir, true)
     }
 
-    fn recent_index(&self) -> Option<usize> {
+    fn recent_index(&mut self) -> Option<usize> {
         None // TODO
     }