From 98b3ed0eec7d2e23368f73bf6c44989739c44ec5 Mon Sep 17 00:00:00 2001
From: Zachary Yedidia <zyedidia@gmail.com>
Date: Sun, 16 Aug 2020 01:03:41 -0400
Subject: [PATCH] Fix undo autocomplete

---
 internal/action/actions.go      | 5 ++++-
 internal/buffer/autocomplete.go | 7 ++++++-
 internal/buffer/eventhandler.go | 2 ++
 internal/buffer/loc.go          | 5 +++++
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/internal/action/actions.go b/internal/action/actions.go
index 3a77e264..5e8f235e 100644
--- a/internal/action/actions.go
+++ b/internal/action/actions.go
@@ -682,7 +682,10 @@ func (h *BufPane) Autocomplete() bool {
 		// don't autocomplete if cursor is on alpha numeric character (middle of a word)
 		return false
 	}
-	return b.Autocomplete(buffer.LSPComplete)
+	if !b.Autocomplete(buffer.LSPComplete) {
+		return b.Autocomplete(buffer.BufferComplete)
+	}
+	return true
 }
 
 // CycleAutocompleteBack cycles back in the autocomplete suggestion list
diff --git a/internal/buffer/autocomplete.go b/internal/buffer/autocomplete.go
index 8e22c1a3..c8dcb8a7 100644
--- a/internal/buffer/autocomplete.go
+++ b/internal/buffer/autocomplete.go
@@ -60,7 +60,12 @@ func (b *Buffer) CycleAutocomplete(forward bool) {
 	if prevCompletion != -1 {
 		prev := b.Completions[prevCompletion]
 		for i := 0; i < len(prev.Edits); i++ {
-			b.UndoOneEvent()
+			if len(prev.Edits[i].Text) != 0 {
+				b.UndoOneEvent()
+			}
+			if !prev.Edits[i].Start.Equal(prev.Edits[i].End) {
+				b.UndoOneEvent()
+			}
 		}
 	}
 
diff --git a/internal/buffer/eventhandler.go b/internal/buffer/eventhandler.go
index 94957c04..651eb5a8 100644
--- a/internal/buffer/eventhandler.go
+++ b/internal/buffer/eventhandler.go
@@ -2,6 +2,7 @@ package buffer
 
 import (
 	"bytes"
+	"log"
 	"time"
 
 	dmp "github.com/sergi/go-diff/diffmatchpatch"
@@ -52,6 +53,7 @@ func (eh *EventHandler) DoTextEvent(t *TextEvent, useUndo bool) {
 	}
 
 	if len(t.Deltas) != 1 {
+		log.Println("Multiple deltas not supported")
 		return
 	}
 
diff --git a/internal/buffer/loc.go b/internal/buffer/loc.go
index 232133cb..019f9db3 100644
--- a/internal/buffer/loc.go
+++ b/internal/buffer/loc.go
@@ -48,6 +48,11 @@ func (l Loc) LessEqual(b Loc) bool {
 	return l == b
 }
 
+// Equal returns true if two locs are equal
+func (l Loc) Equal(b Loc) bool {
+	return l.Y == b.Y && l.X == b.X
+}
+
 // The following functions require a buffer to know where newlines are
 
 // Diff returns the distance between two locations