should allow duplicate __proto__ keys in patterns

[babel-bot]

Original issue submitted by @gsathya in babel/babel#5145

Input Code

result = { __proto__: x, __proto__: y } = value;

Babel Configuration (.babelrc, package.json, cli command)

presets - latest

Expected Behavior

No error

Current Behavior

Error: Redefinition of __proto__ property

Possible Solution

Context

Your Environment

software	version
Babel
node
npm
Operating System

[xtuc]

@gsathya The spec says that:

It is a Syntax Error if PropertyNameList of PropertyDefinitionList contains any duplicate entries for __proto__ [...]

(source)

[gsathya]

When ObjectLiteral appears in a context where ObjectAssignmentPattern is required the Early Error rule is not applied. In addition, it is not applied when initially parsing a CoverParenthesizedExpressionAndArrowParameterList.

[babel-bot]

This issue has been moved to babel/babel#6705.