fix opening links twice when privacy.resistFingerprinting is enabled or on Firefox 91.6+

background_scripts/main.js

@@ -161,7 +161,8 @@ const TabOperations = {
       delete tabConfig["url"];
 
     // Firefox <57 throws an error when openerTabId is used (issue 1238314).
-    const canUseOpenerTabId = !(Utils.isFirefox() && (Utils.compareVersions(Utils.firefoxVersion(), "57") < 0));
+    const canUseOpenerTabId = !Utils.isFirefox() || Utils.firefoxVersion() instanceof Promise
+        || (Utils.compareVersions(Utils.firefoxVersion(), "57") >= 0);
     if (canUseOpenerTabId)
       tabConfig.openerTabId = request.tab.id;
 
@@ -436,7 +437,20 @@ var Frames = {
   onConnect(sender, port) {
     const [tabId, frameId] = [sender.tab.id, sender.frameId];
     port.onDisconnect.addListener(() => Frames.unregisterFrame({tabId, frameId, port}));
-    port.postMessage({handler: "registerFrameId", chromeFrameId: frameId});
+    const message = {handler: "registerFrameId", chromeFrameId: frameId}
+    let firefoxVersion
+    if (Utils.isFirefox()) {
+      firefoxVersion = Utils.firefoxVersion()
+      message.firefoxVersion = firefoxVersion
+    }
+    if (typeof firefoxVersion === "object") {
+      firefoxVersion.then(() => {
+        message.firefoxVersion = Utils.firefoxVersion()
+        port.postMessage(message);
+      })
+    } else {
+      port.postMessage(message);
+    }
     (portsForTab[tabId] != null ? portsForTab[tabId] : (portsForTab[tabId] = {}))[frameId] = port;
 
     // Return our onMessage handler for this port.

content_scripts/vimium_frontend.js

@@ -269,8 +269,11 @@ var Frame = {
     return HintCoordinator[request.messageType](request);
   },
 
-  registerFrameId({chromeFrameId}) {
-    frameId = (root.frameId = (window.frameId = chromeFrameId));
+  registerFrameId(request) {
+    frameId = (root.frameId = (window.frameId = request.chromeFrameId));
+    if (Utils.isFirefox()) {
+      Utils.firefoxVersion = () => request.firefoxVersion
+    }
     // We register a frame immediately only if it is focused or its window isn't tiny.  We register tiny
     // frames later, when necessary.  This affects focusFrame() and link hints.
     if (windowIsFocused() || !DomUtils.windowIsTooSmall()) {

lib/dom_utils.js

@@ -322,9 +322,8 @@ var DomUtils = {
     for (let event of eventSequence) {
       // In firefox prior to 96, simulating a click on an element would be blocked. In 96+,
       // extensions can trigger native click listeners on elements. See #3985.
-      const mayBeBlocked =
-        event === "click" && Utils.isFirefox() && !navigator.userAgentData &&
-            parseInt((navigator.userAgent.match(/\bFirefox\/(\d+)/) || [0, 96])[1]) < 96
+      const mayBeBlocked = event === "click" && Utils.isFirefox() && parseInt(Utils.firefoxVersion()) < 96
+          && /^91\.[0-5](\.|$)/.test(Utils.firefoxVersion())
       const defaultActionShouldTrigger =
         mayBeBlocked && (Object.keys(modifiers).length === 0) &&
             (element.target === "_blank") && element.href &&

lib/utils.js

@@ -17,8 +17,8 @@ if (window.forTrusted == null) {
   });
 }
 
-// TODO(philc): The comment below about its usage doesn't make sense to me. Can we replace this with
-// window.navigator?
+// Note(gdh1995): Info in navigator is not reliable, because sometimes browsers will provide fake values.
+// For example, when `privacy.resistFingerprinting` is enabled on `about:config` of Firefox.
 let browserInfo = null;
 if (window.browser && browser.runtime && browser.runtime.getBrowserInfo)
   browserInfo = browser.runtime.getBrowserInfo();
@@ -31,13 +31,17 @@ var Utils = {
     return () => isFirefox;
   })(),
 
+  // NOTE(gdh1995): Content scripts may access this only after `registerFrameId`
   firefoxVersion: (function() {
     // NOTE(mrmr1993): This only works in the background page.
     let ffVersion = undefined;
     if (browserInfo) {
-      browserInfo.then(browserInfo => ffVersion = browserInfo != null ? browserInfo.version : undefined);
+      browserInfo.then(info => {
+        ffVersion = info != null ? info.version : undefined
+        browserInfo = undefined
+      });
     }
-    return () => ffVersion;
+    return () => ffVersion || browserInfo;
   })(),
 
   getCurrentVersion() {