Fix stray lists in redesigned cache storage

Related issue:
https://old.reddit.com/r/uBlockOrigin/comments/1bxzwf9/

These stray filter lists prevents uBO from properly updating
those filter lists.

src/js/cachestorage.js

@@ -486,16 +486,9 @@ const idbStorage = (( ) => {
 
  // Cache API is subject to quota so we will use it only for what is key
  // performance-wise
- const shouldCache = bin => {
- const out = {};
- for ( const key of Object.keys(bin) ) {
- if ( key.startsWith('cache/' ) ) {
- if ( /^cache\/(compiled|selfie)\//.test(key) === false ) { continue; }
- }
- out[key] = bin[key];
- }
- if ( Object.keys(out).length === 0 ) { return; }
- return out;
+ const shouldCache = key => {
+ if ( key.startsWith('cache/') === false ) { return true; }
+ return /^cache\/(compiled|selfie)\//.test(key);
  };
 
  const fromBlob = data => {
@@ -669,7 +662,12 @@ const idbStorage = (( ) => {
  if ( keys.length === 0 ) { return getAll(); }
  const entries = await getEntries(keys);
  const outbin = {};
+ const toRemove = [];
  for ( const { key, value } of entries ) {
+ if ( shouldCache(key) === false ) {
+ toRemove.push(key);
+ continue;
+ }
  outbin[key] = value;
  }
  if ( argbin instanceof Object && Array.isArray(argbin) === false ) {
@@ -678,12 +676,18 @@ const idbStorage = (( ) => {
  outbin[key] = argbin[key];
  }
  }
+ if ( toRemove.length !== 0 ) {
+ deleteEntries(toRemove);
+ }
  return outbin;
  },
 
  async set(rawbin) {
- const bin = shouldCache(rawbin);
- if ( bin === undefined ) { return; }
+ const bin = {};
+ for ( const key of Object.keys(rawbin) ) {
+ if ( shouldCache(key) === false ) { continue; }
+ bin[key] = rawbin[key];
+ }
  return setEntries(bin);
  },