From 098886bcb6dc2a61810addccdaaa60846366f751 Mon Sep 17 00:00:00 2001
From: Martynas Bagdonas <git.martynas@gmail.com>
Date: Fri, 5 Aug 2022 18:22:30 +0300
Subject: [PATCH] Select existing unloaded tab instead of opening a new one
 Fixes #2740

---
 chrome/content/zotero/tabs.js         |  5 +++++
 chrome/content/zotero/xpcom/reader.js | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/chrome/content/zotero/tabs.js b/chrome/content/zotero/tabs.js
index 6f858c953f..7410bcf333 100644
--- a/chrome/content/zotero/tabs.js
+++ b/chrome/content/zotero/tabs.js
@@ -84,6 +84,11 @@ var Zotero_Tabs = new function () {
 		window.Zotero_Tooltip.stop();
 	};
 
+	this.getTabIDByItemID = function (itemID) {
+		let tab = this._tabs.find(tab => tab.data && tab.data.itemID === itemID);
+		return tab && tab.id;
+	};
+
 	this.init = function () {
 		ReactDOM.render(
 			<TabBar
diff --git a/chrome/content/zotero/xpcom/reader.js b/chrome/content/zotero/xpcom/reader.js
index a990fe0e90..7a10bec7f7 100644
--- a/chrome/content/zotero/xpcom/reader.js
+++ b/chrome/content/zotero/xpcom/reader.js
@@ -1372,6 +1372,17 @@ class Reader {
 		this.triggerAnnotationsImportCheck(itemID);
 		let reader;
 
+		if (!allowDuplicate) {
+			let win = Zotero.getMainWindow();
+			if (win) {
+				let existingTabID = win.Zotero_Tabs.getTabIDByItemID(itemID);
+				if (existingTabID) {
+					win.Zotero_Tabs.select(existingTabID);
+					return;
+				}
+			}
+		}
+
 		if (openInWindow) {
 			reader = this._readers.find(r => r._itemID === itemID && (r instanceof ReaderWindow));
 		}