From a6e75df412c278d0d0553de2e243def96a0d785d Mon Sep 17 00:00:00 2001
From: Maurice Parker <mo@vincode.io>
Date: Tue, 24 Mar 2020 12:21:08 -0500
Subject: [PATCH] Send out an event if we found a cached favicon downloader for
 new homepage URL.  Issue #1940

---
 Shared/Favicons/FaviconDownloader.swift       | 21 +++++++++++++------
 Shared/Favicons/SingleFaviconDownloader.swift |  8 ++++---
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/Shared/Favicons/FaviconDownloader.swift b/Shared/Favicons/FaviconDownloader.swift
index 25c83bcc1..99d8dd2e6 100644
--- a/Shared/Favicons/FaviconDownloader.swift
+++ b/Shared/Favicons/FaviconDownloader.swift
@@ -178,11 +178,6 @@ final class FaviconDownloader {
 
 		remainingFaviconURLs[homePageURL] = nil
 
-		if self.homePageToFaviconURLCache[homePageURL] == nil {
-			self.homePageToFaviconURLCache[homePageURL] = singleFaviconDownloader.faviconURL
-			self.homePageToFaviconURLCacheDirty = true
-		}
-
 		postFaviconDidBecomeAvailableNotification(singleFaviconDownloader.faviconURL)
 	}
 	
@@ -232,8 +227,22 @@ private extension FaviconDownloader {
 
 	func faviconDownloader(withURL faviconURL: String, homePageURL: String?) -> SingleFaviconDownloader {
 
+		var firstTimeSeeingHomepageURL = false
+		
+		if let homePageURL = homePageURL, self.homePageToFaviconURLCache[homePageURL] == nil {
+			self.homePageToFaviconURLCache[homePageURL] = faviconURL
+			self.homePageToFaviconURLCacheDirty = true
+			firstTimeSeeingHomepageURL = true
+		}
+
 		if let downloader = singleFaviconDownloaderCache[faviconURL] {
-			downloader.downloadFaviconIfNeeded()
+			if firstTimeSeeingHomepageURL && !downloader.downloadFaviconIfNeeded() {
+				// This is to handle the scenario where we have different homepages, but the same favicon.
+				// This happens for Twitter and probably other sites like Blogger.  Because the favicon
+				// is cached, we wouldn't send out a notification that it is now available unless we send
+				// it here.
+				postFaviconDidBecomeAvailableNotification(faviconURL)
+			}
 			return downloader
 		}
 
diff --git a/Shared/Favicons/SingleFaviconDownloader.swift b/Shared/Favicons/SingleFaviconDownloader.swift
index 8a37486f3..9ef2b61df 100644
--- a/Shared/Favicons/SingleFaviconDownloader.swift
+++ b/Shared/Favicons/SingleFaviconDownloader.swift
@@ -48,21 +48,23 @@ final class SingleFaviconDownloader {
 		findFavicon()
 	}
 
-	func downloadFaviconIfNeeded() {
+	func downloadFaviconIfNeeded() -> Bool {
 
 		// If we don’t have an image, and lastDownloadAttemptDate is a while ago, try again.
 
 		if let _ = iconImage {
-			return
+			return false
 		}
 
 		let retryInterval: TimeInterval = 30 * 60 // 30 minutes
 		if Date().timeIntervalSince(lastDownloadAttemptDate) < retryInterval {
-			return
+			return false
 		}
 
 		lastDownloadAttemptDate = Date()
 		findFavicon()
+		
+		return true
 	}
 }