Incorrect parentheses in warning message

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 6.4.1
$ cat > test.hs
main | x <- 1*2+3*4 = undefined
$ ghc test.hs

test.hs:1:5:
    Warning: accepting non-standard pattern guards (-fglasgow-exts to suppress this message)
                 [x <- ((1 * 2) + 3) * 4, undefined]

The arithmetic expression is parenthesized incorrectly in the warning.

Trac metadata

Trac field	Value
Version	6.4.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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