Make popup panel reflect state of the actual blocked page

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1954

src/js/messaging.js

@@ -299,15 +299,24 @@ const onMessage = function(request, sender, callback) {
         µb.openNewTab(request.details);
         break;
 
-    case 'reloadTab':
-        if ( vAPI.isBehindTheSceneTabId(request.tabId) === false ) {
-            vAPI.tabs.reload(request.tabId, request.bypassCache === true);
-            if ( request.select && vAPI.tabs.select ) {
-                vAPI.tabs.select(request.tabId);
+    // https://github.com/uBlockOrigin/uBlock-issues/issues/1954
+    //   In case of document-blocked page, navigate to blocked URL instead
+    //   of forcing a reload.
+    case 'reloadTab': {
+        if ( vAPI.isBehindTheSceneTabId(request.tabId) ) { break; }
+        const { tabId, bypassCache, url, select } = request;
+        vAPI.tabs.get(tabId).then(tab => {
+            if ( url && tab && url !== tab.url ) {
+                vAPI.tabs.replace(tabId, url);
+            } else {
+                vAPI.tabs.reload(tabId, bypassCache === true);
             }
+        });
+        if ( select && vAPI.tabs.select ) {
+            vAPI.tabs.select(tabId);
         }
         break;
-
+    }
     case 'setWhitelist':
         µb.netWhitelist = µb.whitelistFromString(request.whitelist);
         µb.saveWhitelist();

src/js/popup-fenix.js

@@ -1077,6 +1077,7 @@ const reloadTab = function(ev) {
     messaging.send('popupPanel', {
         what: 'reloadTab',
         tabId: popupData.tabId,
+        url: popupData.pageURL,
         select: vAPI.webextFlavor.soup.has('mobile'),
         bypassCache: ev.ctrlKey || ev.metaKey || ev.shiftKey,
     });

src/js/tab.js

@@ -339,14 +339,9 @@ const onPopupUpdated = (( ) => {
             return;
         }
 
-        // If the page URL is that of our "blocked page" URL, extract the URL
+        // If the page URL is that of our document-blocked URL, extract the URL
         // of the page which was blocked.
-        if ( targetURL.startsWith(vAPI.getURL('document-blocked.html')) ) {
-            const matches = /details=([^&]+)/.exec(targetURL);
-            if ( matches !== null ) {
-                targetURL = JSON.parse(decodeURIComponent(matches[1])).url;
-            }
-        }
+        targetURL = µb.pageURLFromMaybeDocumentBlockedURL(targetURL);
 
         // MUST be reset before code below is called.
         const fctxt = µb.filteringContext.duplicate();
@@ -683,6 +678,9 @@ housekeep itself.
 
     // Update just force all properties to be updated to match the most recent
     // root URL.
+    // https://github.com/uBlockOrigin/uBlock-issues/issues/1954
+    //   In case of document-blocked page, use the blocked page URL as the
+    //   context.
     TabContext.prototype.update = function() {
         this.netFilteringReadTime = 0;
         if ( this.stack.length === 0 ) {
@@ -694,7 +692,7 @@ housekeep itself.
             return;
         }
         const stackEntry = this.stack[this.stack.length - 1];
-        this.rawURL = stackEntry.url;
+        this.rawURL = µb.pageURLFromMaybeDocumentBlockedURL(stackEntry.url);
         this.normalURL = µb.normalizeTabURL(this.tabId, this.rawURL);
         this.origin = originFromURI(this.normalURL);
         this.rootHostname = hostnameFromURI(this.origin);

src/js/ublock.js

@@ -656,3 +656,16 @@ const matchBucket = function(url, hostname, bucket, start) {
 }
 
 /******************************************************************************/
+
+µb.pageURLFromMaybeDocumentBlockedURL = function(pageURL) {
+    if ( pageURL.startsWith(vAPI.getURL('/document-blocked.html?')) ) {
+        try {
+            const url = new URL(pageURL);
+            return JSON.parse(url.searchParams.get('details')).url;
+        } catch(ex) {
+        }
+    }
+    return pageURL;
+};
+
+/******************************************************************************/