Fix broken forward compatibility re. imported lists

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1480

Forward compatiblity was broken due to `externalLists`
being converted into an Array from a string, i.e.
downgrading to uBO 1.32.4 was completely breaking uBO.

This commit restores `externalLists` as a string which
is what older versions of uBO expect.

A new property `importedLists` has been created to
hold the imported lists as an array, while
`externalLists` will be kept around for a while until
it is completely removed in some future.

src/js/background.js

@@ -92,10 +92,11 @@ const µBlock = (( ) => { // jshint ignore:line
         colorBlindFriendly: false,
         contextMenuEnabled: true,
         dynamicFilteringEnabled: false,
-        externalLists: [],
+        externalLists: '',
         firewallPaneMinimized: true,
         hyperlinkAuditingDisabled: true,
         ignoreGenericCosmeticFilters: vAPI.webextFlavor.soup.has('mobile'),
+        importedLists: [],
         largeMediaSize: 50,
         parseAllABPHideFilters: true,
         popupPanelSections: 0b111,

src/js/messaging.js

@@ -949,9 +949,9 @@ const restoreUserData = async function(request) {
         userData.hostnameSwitchesString += '\nno-csp-reports: * true';
     }
 
-    // List of external lists is meant to be an array.
+    // List of external lists is meant to be a string.
-    if ( typeof userData.externalLists === 'string' ) {
+    if ( Array.isArray(userData.externalLists) ) {
-        userData.externalLists = userData.externalLists.trim().split(/[\n\r]+/);
+        userData.externalLists = userData.externalLists.join('\n');
     }
 
     // https://github.com/chrisaljoudi/uBlock/issues/1102

src/js/start.js

@@ -160,9 +160,18 @@ const onNetWhitelistReady = function(netWhitelistRaw, adminExtra) {
 // User settings are in memory
 
 const onUserSettingsReady = function(fetched) {
-    // List of external lists is meant to be an array
+    // `externalLists` will be deprecated in some future, it is kept around
-    if ( typeof fetched.externalLists === 'string' ) {
+    // for forward compatibility purpose, and should reflect the content of
-        fetched.externalLists =
+    // `importedLists`.
+    if ( Array.isArray(fetched.externalLists) ) {
+        fetched.externalLists = fetched.externalLists.join('\n');
+        vAPI.storage.set({ externalLists: fetched.externalLists });
+    }
+    if (
+        fetched.importedLists.length === 0 &&
+        fetched.externalLists !== ''
+    ) {
+        fetched.importedLists =
             fetched.externalLists.trim().split(/[\n\r]+/);
     }
 

src/js/storage.js

@@ -116,10 +116,17 @@
         this.userSettings,
         this.userSettingsDefault
     );
+
+    // `externalLists` will be deprecated in some future, it is kept around
+    // for forward compatibility purpose, and should reflect the content of
+    // `importedLists`.
+    this.userSettings.externalLists =
+        this.userSettings.importedLists.join('\n');
+
     const toRemove = [];
     for ( const key in this.userSettings ) {
         if ( this.userSettings.hasOwnProperty(key) === false ) { continue; }
-        if ( toSave.hasOwnProperty(key) === false ) { continue; }
+        if ( toSave.hasOwnProperty(key) ) { continue; }
         toRemove.push(key);
     }
     if ( toRemove.length !== 0 ) {
@@ -368,7 +375,7 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
 
 µBlock.applyFilterListSelection = function(details) {
     let selectedListKeySet = new Set(this.selectedFilterLists);
-    let externalLists = this.userSettings.externalLists.slice();
+    let importedLists = this.userSettings.importedLists.slice();
 
     // Filter lists to select
     if ( Array.isArray(details.toSelect) ) {
@@ -386,9 +393,9 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
         for ( let i = 0, n = details.toRemove.length; i < n; i++ ) {
             const assetKey = details.toRemove[i];
             selectedListKeySet.delete(assetKey);
-            const pos = externalLists.indexOf(assetKey);
+            const pos = importedLists.indexOf(assetKey);
             if ( pos !== -1 ) {
-                externalLists.splice(pos, 1);
+                importedLists.splice(pos, 1);
             }
             this.removeFilterList(assetKey);
         }
@@ -418,7 +425,7 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
             }
             return url;
         };
-        const importedSet = new Set(this.listKeysFromCustomFilterLists(externalLists));
+        const importedSet = new Set(this.listKeysFromCustomFilterLists(importedLists));
         const toImportSet = new Set(this.listKeysFromCustomFilterLists(details.toImport));
         for ( const urlKey of toImportSet ) {
             if ( importedSet.has(urlKey) ) {
@@ -431,12 +438,12 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
             }
             selectedListKeySet.add(assetKey);
         }
-        externalLists = Array.from(importedSet).sort();
+        importedLists = Array.from(importedSet).sort();
     }
 
     const result = Array.from(selectedListKeySet);
-    if ( externalLists.join() !== this.userSettings.externalLists.join() ) {
+    if ( importedLists.join() !== this.userSettings.importedLists.join() ) {
-        this.userSettings.externalLists = externalLists;
+        this.userSettings.importedLists = importedLists;
         this.saveUserSettings();
     }
     this.saveSelectedFilterLists(result);
@@ -597,7 +604,7 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
 
     // Custom filter lists.
     const importedListKeys = this.listKeysFromCustomFilterLists(
-        this.userSettings.externalLists
+        this.userSettings.importedLists
     );
     for ( const listKey of importedListKeys ) {
         const entry = {
@@ -631,7 +638,7 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
         newAvailableLists[listURL] = newEntry;
         this.assets.registerAssetSource(listURL, newEntry);
         importedListKeys.push(listURL);
-        this.userSettings.externalLists.push(listURL.trim());
+        this.userSettings.importedLists.push(listURL.trim());
         this.saveUserSettings();
         this.saveSelectedFilterLists([ listURL ], true);
     };
@@ -1351,11 +1358,6 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
     if ( typeof data.userSettings === 'object' ) {
         const µbus = this.userSettings;
         const adminus = data.userSettings;
-        // List of external lists is meant to be an array.
-        if ( typeof adminus.externalLists === 'string' ) {
-            adminus.externalLists =
-                adminus.externalLists.trim().split(/[\n\r]+/);
-        }
         for ( const name in µbus ) {
             if ( µbus.hasOwnProperty(name) === false ) { continue; }
             if ( adminus.hasOwnProperty(name) === false ) { continue; }
@@ -1371,13 +1373,14 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
         Array.isArray(toOverwrite.filterLists) &&
         toOverwrite.filterLists.length !== 0
     ) {
-        const externalLists = [];
+        const importedLists = [];
         for ( const list of toOverwrite.filterLists ) {
             if ( /^[a-z-]+:\/\//.test(list) === false ) { continue; }
-            externalLists.push(list);
+            importedLists.push(list);
         }
-        if ( externalLists.length !== 0 ) {
+        if ( importedLists.length !== 0 ) {
-            bin.externalLists = externalLists;
+            bin.importedLists = importedLists;
+            bin.externalLists = importedLists.join('\n');
         }
         bin.selectedFilterLists = toOverwrite.filterLists;
         binNotEmpty = true;

src/js/utils.js

@@ -687,6 +687,8 @@
 
 /******************************************************************************/
 
+// TODO: properly compare arrays
+
 µBlock.getModifiedSettings = function(edit, orig = {}) {
     const out = {};
     for ( const prop in edit ) {