From 67db38133299daa6cab02a4590875056bb3951a1 Mon Sep 17 00:00:00 2001
From: Adnan Maolood <me@adnano.co>
Date: Wed, 22 Sep 2021 13:14:39 -0400
Subject: [PATCH] tab: Prevent duplicate history entries

Resolves #55
---
 tab.go | 37 ++++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 11 deletions(-)

diff --git a/tab.go b/tab.go
index 58f99fe..70c8b47 100644
--- a/tab.go
+++ b/tab.go
@@ -259,6 +259,8 @@ func (t *Tab) Back() bool {
 	if t.Busy() {
 		return false
 	}
+	t.mu.Lock()
+	defer t.mu.Unlock()
 	t.saveScroll()
 	if t.page > 0 {
 		t.page--
@@ -273,6 +275,8 @@ func (t *Tab) Forward() bool {
 	if t.Busy() {
 		return false
 	}
+	t.mu.Lock()
+	defer t.mu.Unlock()
 	t.saveScroll()
 	if t.page < len(t.pages)-1 {
 		t.page++
@@ -332,7 +336,7 @@ func (t *Tab) doContext(req *gemini.Request) context.Context {
 		req.Certificate = &cert
 	}
 
-	t.newPage(req)
+	t.newPage()
 	return ctx
 }
 
@@ -413,6 +417,7 @@ func (t *Tab) do(ctx context.Context, req *gemini.Request, via []*gemini.Request
 		return nil
 
 	case gemini.StatusSuccess:
+		t.removeDuplicatePage()
 		t.buf.Reset()
 		resp.Body = &teeReader{resp.Body, &t.buf}
 		return t.handle(req, resp)
@@ -605,23 +610,33 @@ func (t *Tab) shouldPromptRedirect(req *gemini.Request, via *gemini.Request) boo
 	return external || nonGemini
 }
 
-func (t *Tab) newPage(req *gemini.Request) {
+func (t *Tab) newPage() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
 	if len(t.pages) != 0 {
-		if req.URL.String() == t.pages[t.page].URL {
-			// Reset page style
-			t.pages[t.page].Style = tcell.StyleDefault
-			return
-		}
-		if t.page != len(t.pages)-1 {
+		t.page++
+		if t.page != len(t.pages) {
 			// Truncate history going forward
-			t.pages = t.pages[:t.page+1]
+			t.pages = t.pages[:t.page]
 		}
-		t.page++
 	}
-
 	t.pages = append(t.pages, Page{})
 }
 
+func (t *Tab) removeDuplicatePage() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if len(t.pages) < 2 {
+		return
+	}
+	i, j := len(t.pages)-1, len(t.pages)-2
+	if t.pages[i].URL == t.pages[j].URL {
+		t.pages[j] = t.pages[i]
+		t.pages = t.pages[:i]
+		t.page--
+	}
+}
+
 func (t *Tab) handle(req *gemini.Request, resp *gemini.Response) error {
 	defer resp.Body.Close()
 
-- 
2.38.5