Make sure icon URLs are always absolute

Regression introduced in #1907

internal/reader/handler/handler.go

@@ -220,9 +220,9 @@ func RefreshFeed(store *storage.Storage, userID, feedID int64, forceRefresh bool
 	return nil
 }
 
-func checkFeedIcon(store *storage.Storage, feedID int64, websiteURL, iconURL, userAgent string, fetchViaProxy, allowSelfSignedCertificates bool) {
+func checkFeedIcon(store *storage.Storage, feedID int64, websiteURL, feedIconURL, userAgent string, fetchViaProxy, allowSelfSignedCertificates bool) {
 	if !store.HasIcon(feedID) {
-		icon, err := icon.FindIcon(websiteURL, iconURL, userAgent, fetchViaProxy, allowSelfSignedCertificates)
+		icon, err := icon.FindIcon(websiteURL, feedIconURL, userAgent, fetchViaProxy, allowSelfSignedCertificates)
 		if err != nil {
 			logger.Debug(`[CheckFeedIcon] %v (feedID=%d websiteURL=%s)`, err, feedID, websiteURL)
 		} else if icon == nil {

internal/reader/icon/finder.go

@@ -21,10 +21,51 @@ import (
 )
 
 // FindIcon try to find the website's icon.
-func FindIcon(websiteURL, iconURL, userAgent string, fetchViaProxy, allowSelfSignedCertificates bool) (*model.Icon, error) {
+func FindIcon(websiteURL, feedIconURL, userAgent string, fetchViaProxy, allowSelfSignedCertificates bool) (icon *model.Icon, err error) {
-	if iconURL == "" {
+	if feedIconURL == "" {
+		feedIconURL, err = fetchHTMLDocumentAndFindIconURL(websiteURL, userAgent, fetchViaProxy, allowSelfSignedCertificates)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if strings.HasPrefix(feedIconURL, "data:") {
+		return parseImageDataURL(feedIconURL)
+	}
+
+	feedIconURL, err = generateIconURL(websiteURL, feedIconURL)
+	if err != nil {
+		return nil, err
+	}
+
+	if icon, err = downloadIcon(feedIconURL, userAgent, fetchViaProxy, allowSelfSignedCertificates); err != nil {
+		return nil, err
+	}
+
+	return icon, nil
+}
+
+func generateIconURL(websiteURL, feedIconURL string) (iconURL string, err error) {
+	feedIconURL = strings.TrimSpace(feedIconURL)
+
+	if feedIconURL == "" {
+		iconURL, err = urllib.JoinBaseURLAndPath(urllib.RootURL(websiteURL), "favicon.ico")
+		if err != nil {
+			return "", fmt.Errorf(`icon: unable to join base URL and path: %w`, err)
+		}
+	} else {
+		iconURL, err = urllib.AbsoluteURL(websiteURL, feedIconURL)
+		if err != nil {
+			return "", fmt.Errorf(`icon: unable to convert icon URL to absolute URL: %w`, err)
+		}
+	}
+
+	return iconURL, nil
+}
+
+func fetchHTMLDocumentAndFindIconURL(websiteURL, userAgent string, fetchViaProxy, allowSelfSignedCertificates bool) (string, error) {
 	rootURL := urllib.RootURL(websiteURL)
-		logger.Debug("[FindIcon] Trying to find an icon: rootURL=%q websiteURL=%q userAgent=%q", rootURL, websiteURL, userAgent)
+	logger.Debug("[FindIcon] Find icon from HTML webpage: %s", rootURL)
 
 	clt := client.NewClientWithConfig(rootURL, config.Opts)
 	clt.WithUserAgent(userAgent)
@@ -36,33 +77,17 @@ func FindIcon(websiteURL, iconURL, userAgent string, fetchViaProxy, allowSelfSig
 
 	response, err := clt.Get()
 	if err != nil {
-			return nil, fmt.Errorf("icon: unable to download website index page: %v", err)
+		return "", fmt.Errorf("icon: unable to download website index page: %v", err)
 	}
 
 	if response.HasServerFailure() {
-			return nil, fmt.Errorf("icon: unable to download website index page: status=%d", response.StatusCode)
+		return "", fmt.Errorf("icon: unable to download website index page: status=%d", response.StatusCode)
 	}
 
-		iconURL, err = parseDocument(rootURL, response.Body)
+	return findIconURLFromHTMLDocument(response.Body)
-		if err != nil {
-			return nil, err
-		}
 }
 
-	if strings.HasPrefix(iconURL, "data:") {
+func findIconURLFromHTMLDocument(body io.Reader) (string, error) {
-		return parseImageDataURL(iconURL)
-	}
-
-	logger.Debug("[FindIcon] Fetching icon => %s", iconURL)
-	icon, err := downloadIcon(iconURL, userAgent, fetchViaProxy, allowSelfSignedCertificates)
-	if err != nil {
-		return nil, err
-	}
-
-	return icon, nil
-}
-
-func parseDocument(websiteURL string, data io.Reader) (string, error) {
 	queries := []string{
 		"link[rel='shortcut icon']",
 		"link[rel='Shortcut Icon']",
@@ -70,7 +95,7 @@ func parseDocument(websiteURL string, data io.Reader) (string, error) {
 		"link[rel='icon']",
 	}
 
-	doc, err := goquery.NewDocumentFromReader(data)
+	doc, err := goquery.NewDocumentFromReader(body)
 	if err != nil {
 		return "", fmt.Errorf("icon: unable to read document: %v", err)
 	}
@@ -88,12 +113,6 @@ func parseDocument(websiteURL string, data io.Reader) (string, error) {
 		}
 	}
 
-	if iconURL == "" {
-		iconURL = urllib.RootURL(websiteURL) + "favicon.ico"
-	} else {
-		iconURL, _ = urllib.AbsoluteURL(websiteURL, iconURL)
-	}
-
 	return iconURL, nil
 }
 

internal/reader/icon/finder_test.go

@@ -92,12 +92,59 @@ func TestParseDocumentWithWhitespaceIconURL(t *testing.T) {
 		/static/img/favicon.ico
 	">`
 
-	iconURL, err := parseDocument("http://www.example.org/", strings.NewReader(html))
+	iconURL, err := findIconURLFromHTMLDocument(strings.NewReader(html))
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	if iconURL != "http://www.example.org/static/img/favicon.ico" {
+	if iconURL != "/static/img/favicon.ico" {
+		t.Errorf(`Invalid icon URL, got %q`, iconURL)
+	}
+}
+
+func TestGenerateIconURL(t *testing.T) {
+	iconURL, err := generateIconURL("https://example.org/", "/favicon.png")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if iconURL != "https://example.org/favicon.png" {
+		t.Errorf(`Invalid icon URL, got %q`, iconURL)
+	}
+
+	iconURL, err = generateIconURL("https://example.org/", "img/favicon.png")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if iconURL != "https://example.org/img/favicon.png" {
+		t.Errorf(`Invalid icon URL, got %q`, iconURL)
+	}
+
+	iconURL, err = generateIconURL("https://example.org/", "https://example.org/img/favicon.png")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if iconURL != "https://example.org/img/favicon.png" {
+		t.Errorf(`Invalid icon URL, got %q`, iconURL)
+	}
+
+	iconURL, err = generateIconURL("https://example.org/", "//example.org/img/favicon.png")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if iconURL != "https://example.org/img/favicon.png" {
+		t.Errorf(`Invalid icon URL, got %q`, iconURL)
+	}
+
+	iconURL, err = generateIconURL("https://example.org/", "  ")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if iconURL != "https://example.org/favicon.ico" {
 		t.Errorf(`Invalid icon URL, got %q`, iconURL)
 	}
 }

internal/storage/icon.go

@@ -27,7 +27,7 @@ func (s *Storage) IconByID(iconID int64) (*model.Icon, error) {
 	if err == sql.ErrNoRows {
 		return nil, nil
 	} else if err != nil {
-		return nil, fmt.Errorf("Unable to fetch icon by hash: %v", err)
+		return nil, fmt.Errorf("store: unable to fetch icon by hash: %v", err)
 	}
 
 	return &icon, nil