Make the webNavigation permission optional

Capture quality may be silently degraded if the permission
is not granted. No attempt to get active subframe is performed.

README.org

@@ -426,8 +426,9 @@ Chrome: "Read your browsing history".
 It is necessary to reliably restore tree of nested frames.
 Consider the case when some element is focused in a subframe
 and capture is invoked using keyboard shortcut.
-Maybe I will add a less reliable fallback in future
-to make this permission optional.
+Another case is context menu invoked in a deeply nested frame.
+
+You may grant this permission on the extension options page.[fn:3]
 
 *** Access browser tabs (=tabs=)
 :PROPERTIES:

background/lr_settings.js

@@ -276,6 +276,23 @@ var lr_settings = lr_util.namespace(lr_settings, function lr_settings() {
 			host: true,
 			parent: "misc",
 		});
+		this.registerOption({
+			name: "permissions.webNavigation",
+			title: 'Access browser activity during navigation ("webNavigation")',
+			version: "0.4",
+			description: [
+				"Relevant to frames and embedded objects.",
+				"Without this permission the extension may be unable",
+				"to find active frame when invoked using",
+				"the toolbar button or the shortcut.",
+				"",
+				"Context menu is affected in less degree,",
+				"but capture info may still be incomplete",
+				"in the case of multiple level of nested frames."
+			],
+			type: "permission",
+			parent: "misc",
+		});
 	};
 
 	this.load = async function() {

background/lr_tabframe.js

@@ -40,6 +40,25 @@ var lr_tabframe = lr_util.namespace(lr_tabframe, function lr_tabframe() {
 		};
 	}
 
+	lr_tabframe._hasWebNavigationPermission = async function _hasWebNavigationPermission() {
+		if (chrome.webNavigation?.getAllFrames === undefined) {
+			return false;
+		}
+		// Chromium-130 throws synchronously after `permissions.remove`
+		//     chrome.webNavigation.getAllFrames({tabId: -1})
+		//     Error: 'webNavigation.getAllFrames' is not available in this context.
+		//
+		// If the permission is not available
+		//
+		//     TypeError: Error in invocation of webNavigation.getAllFrames(object details, function callback): Error at parameter 'details': Error at property 'tabId': Value must be at least 0.
+		try {
+			return await bapi.permissions.contains({ permissions: [ "webNavigation" ] });
+		} catch (ex) {
+			Promise.reject(ex);
+		}
+		return false;
+	}
+
 	Object.assign(this, {
 		FORMAT, VERSION,
 		makeCapture,
@@ -147,7 +166,7 @@ function focusedFrameChain(frameMap) {
 async function lrGetAllFrames(tab) {
 	// Likely redundant protection, tab should be valid here
 	const tabId = tab != null ? tab.id : -1;
-	if (!(tabId >= 0)) {
+	if (!(tabId >= 0) || ! await lr_tabframe._hasWebNavigationPermission()) {
 		// May happen in Chromium-87 when context menu is invoked for a PDF file
 		// but should be handled by caller since <embed> element
 		// in Chrome created for PDF file has its own "tab".
@@ -515,12 +534,12 @@ async function lrGatherTabInfo(tab, clickData, activeTab, executor) {
 	// allows to avoid noise due to e.g. empty `<iframe>` somewhere on the page.
 	executor.step(
 		{ errorAction: lr_executor.ERROR_IS_WARNING },
-		function lrCheckFramePermissionsErrors(chain) {
+		async function lrCheckFramePermissionsErrors(chain) {
 			let count = 0;
-			let first = true;
+			let checkForActiveElement = await lr_tabframe._hasWebNavigationPermission();
 			for (const wrappedFrame of chain) {
-				if (first) {
-					first = false;
+				if (checkForActiveElement) {
+					checkForActiveElement = false;
 					const node = wrappedFrame?.summary?.activeElementNode?.toUpperCase?.();
 					if (node && ["IFRAME", "FRAME", "OBJECT", "EMBED"].indexOf(node) >= 0) {
 						// In the case of navigation `frame.src` does not match

manifest-chrome.json

@@ -22,13 +22,13 @@
 		"scripting",
 		"storage",
 		"activeTab",
-		"contextMenus",
-		"webNavigation"
+		"contextMenus"
 	],
 	"optional_permissions": [
 		"clipboardWrite",
 		"nativeMessaging",
 		"tabs",
+		"webNavigation",
 		"offscreen",
 		"tabGroups"
 	],

manifest-common.yaml

@@ -41,7 +41,6 @@ permissions:
 - storage
 - activeTab
 - contextMenus
-- webNavigation
 optional_permissions:
 # `clipboardWrite` allows to copy to clipboard any time.
 # Added to reliably copy capture when preview page is disabled
@@ -63,3 +62,4 @@ optional_permissions:
 - clipboardWrite
 - nativeMessaging
 - tabs
+- webNavigation

manifest-firefox.json

@@ -23,13 +23,13 @@
 		"storage",
 		"activeTab",
 		"contextMenus",
-		"webNavigation",
 		"menus"
 	],
 	"optional_permissions": [
 		"clipboardWrite",
 		"nativeMessaging",
 		"tabs",
+		"webNavigation",
 		"<all_urls>"
 	],
 	"manifest_version": 2,