From a6500ba7111aab230e32334059fadcc0450f8ad6 Mon Sep 17 00:00:00 2001
From: Jeremy Ruston <jeremy@jermolene.com>
Date: Fri, 21 Jun 2019 15:19:51 +0100
Subject: [PATCH] DynaView: Suppress local storage errors

---
 plugins/tiddlywiki/dynaview/dynaview.js | 36 ++++++++++++++-----------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/plugins/tiddlywiki/dynaview/dynaview.js b/plugins/tiddlywiki/dynaview/dynaview.js
index 4c0b846a8..271a41985 100644
--- a/plugins/tiddlywiki/dynaview/dynaview.js
+++ b/plugins/tiddlywiki/dynaview/dynaview.js
@@ -31,6 +31,8 @@ var LOCAL_STORAGE_KEY_PREFIX = "tw5-dynaview-scroll-position#";
 
 var hasRestoredScrollPosition = false;
 
+var localStorageHasFailed = false;
+
 exports.startup = function() {
 	var topmost = null, lastScrollY;
 	$tw.boot.disableStartupNavigation = true;
@@ -165,16 +167,18 @@ function updateAddressBar() {
 }
 
 function saveScrollPosition() {
-	if(hasRestoredScrollPosition && $tw.wiki.getTiddlerText("$:/config/DynaView/RestoreScrollPositionAtStartup") === "yes") {
-		var top = findTopmostTiddler();
-		if(top.element) {
-			try {
-				window.localStorage.setItem(LOCAL_STORAGE_KEY_PREFIX + window.location.pathname,JSON.stringify({
-					title: top.title,
-					offset: top.offset
-				}));
-			} catch(e) {
-				console.log("Error setting local storage",e)
+	if(!localStorageHasFailed) {
+		if(hasRestoredScrollPosition && $tw.wiki.getTiddlerText("$:/config/DynaView/RestoreScrollPositionAtStartup") === "yes") {
+			var top = findTopmostTiddler();
+			if(top.element) {
+				try {
+					window.localStorage.setItem(LOCAL_STORAGE_KEY_PREFIX + window.location.pathname,JSON.stringify({
+						title: top.title,
+						offset: top.offset
+					}));
+				} catch(e) {
+					localStorageHasFailed = true;
+				}
 			}
 		}
 	}
@@ -182,11 +186,13 @@ function saveScrollPosition() {
 
 function restoreScrollPosition() {
 	var json;
-	try {
-		json = JSON.parse(window.localStorage.getItem(LOCAL_STORAGE_KEY_PREFIX + window.location.pathname));
-	} catch(e) {
-		// Ignore errors
-	};
+	if(!localStorageHasFailed) {
+		try {
+			json = JSON.parse(window.localStorage.getItem(LOCAL_STORAGE_KEY_PREFIX + window.location.pathname));
+		} catch(e) {
+			localStorageHasFailed = true;
+		};		
+	}
 	return json;
 }