Better detect invalid cosmetic filters

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/2170
This commit is contained in:
Raymond Hill 2022-07-15 13:35:56 -04:00
parent 019f3f1739
commit a8ca5127c9
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GPG key ID: 25E1490B761470C2

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@ -19,7 +19,7 @@
Home: https://github.com/gorhill/uBlock
*/
/* globals CSSStyleSheet, document */
/* globals document */
'use strict';
@ -1333,20 +1333,17 @@ Parser.prototype.SelectorCompiler = class {
[ 'matches-css-before', ':matches-css-before' ],
]);
this.reSimpleSelector = /^[#.]?[A-Za-z_][\w-]*$/;
// https://developer.mozilla.org/en-US/docs/Web/API/CSSStyleSheet#browser_compatibility
// Firefox does not support constructor for CSSStyleSheet
this.stylesheet = (( ) => {
this.styleElement = (( ) => {
if ( typeof document !== 'object' ) { return null; }
if ( document instanceof Object === false ) { return null; }
if ( document === null ) { return null; }
try {
return new CSSStyleSheet();
const styleElement = document.createElement('style');
styleElement.disabled = true;
document.body.append(styleElement);
return styleElement;
} catch(ex) {
}
const style = document.createElement('style');
document.body.append(style);
const stylesheet = style.sheet;
style.remove();
return stylesheet;
return null;
})();
this.div = (( ) => {
if ( typeof document !== 'object' ) { return null; }
@ -1468,18 +1465,17 @@ Parser.prototype.SelectorCompiler = class {
// Forbid multiple and unexpected CSS style declarations.
sheetSelectable(s) {
if ( this.reSimpleSelector.test(s) ) { return true; }
if ( this.stylesheet === null ) { return true; }
if ( this.styleElement === null ) { return true; }
try {
this.stylesheet.insertRule(`${s}{color:red}`);
if ( this.stylesheet.cssRules.length !== 1 ) { return false; }
const style = this.stylesheet.cssRules[0].style;
this.styleElement.textContent = `${s}{color:red}`;
const rules = this.styleElement.sheet.cssRules;
if ( rules.length !== 1 ) { return false; }
const style = rules[0].style;
if ( style.length !== 1 ) { return false; }
if ( style.getPropertyValue('color') !== 'red' ) { return false; }
this.stylesheet.deleteRule(0);
if ( style.getPropertyValue('color') === 'red' ) { return true; }
} catch (ex) {
return false;
}
return true;
return false;
}
// https://github.com/uBlockOrigin/uBlock-issues/issues/1806
@ -1600,17 +1596,15 @@ Parser.prototype.SelectorCompiler = class {
// - opening comment `/*`
compileStyleProperties(s) {
if ( /image-set\(|url\(|\/\s*\/|\\|\/\*/i.test(s) ) { return; }
if ( this.stylesheet === null ) { return s; }
if ( this.styleElement === null ) { return s; }
let valid = false;
try {
this.stylesheet.insertRule(`a{${s}}`);
const rules = this.stylesheet.cssRules;
valid = rules.length !== 0 && rules[0].style.cssText !== '';
this.styleElement.textContent = `a{${s}} b{color:red;}`;
const rules = this.styleElement.sheet.cssRules;
valid = rules.length >= 2 &&
rules[0].style.cssText !== '' &&
rules[1].style.cssText !== '';
} catch(ex) {
return;
}
if ( this.stylesheet.cssRules.length !== 0 ) {
this.stylesheet.deleteRule(0);
}
if ( valid ) { return s; }
}
@ -1781,8 +1775,12 @@ Parser.prototype.SelectorCompiler = class {
if ( i === n ) { break; }
}
// when there is an explicit action, nothing should be left to parse.
if ( action !== undefined && opPrefixBeg < n ) { return; }
// No task found: then we have a CSS selector.
// At least one task found: nothing should be left to parse.
// At least one task found: either nothing or a valid plain CSS selector
// should be left to parse
if ( tasks.length === 0 ) {
if ( action === undefined ) {
prefix = raw;
@ -1796,7 +1794,6 @@ Parser.prototype.SelectorCompiler = class {
}
} else if ( opPrefixBeg < n ) {
if ( action !== undefined ) { return; }
const spath = this.compileSpathExpression(raw.slice(opPrefixBeg));
if ( spath === undefined ) { return; }
tasks.push([ ':spath', spath ]);