Parenthesis removed, resulting in altered execution

var obj = {val:true}
alert( true  ||  **(**true &&  obj.value == true**)**)  //true
alert( true  ||  true &&  obj.value == true)  //false
 
 becomes
 
var obj = { 'val': !![] };
alert(!![] || !![] && obj['value'] == !![]); //false
alert(!![] || !![] && obj['value'] == !![]); //false

Tested in Adobe ESTK after running Gulp with the following options:
{
compact: false,
controlFlowFlattening: false, //KILLS JSX
deadCodeInjection: false, //KILLS JSX
disableConsoleOutput: false,
identifierNamesGenerator: 'mangled',
renameGlobals: false,
selfDefending: false,
sourceMap: false,
stringArray: false,
rotateStringArray: false,
stringArrayEncoding: false,
splitStrings: false,
transformObjectKeys: false,
unicodeEscapeSequence: false
}

Reproduce the two alert expressions through the Gulp plugin using the listed options, then compare the original and generated JavaScript. Check why the parenthesized expression changes behavior and verify the fix by confirming both generated alerts preserve the intended execution result.

Written by the indexing model from the issue text.