Serious typo in IntMap.hs
Someone has recently (since 6.8.3) taken a "style" pass over IntMap.hs
. Apparently they didn't like reusing identifiers in different scopes, so they changed this function (at the very core of IntMap
) from this
highestBitMask :: Nat -> Nat
highestBitMask x
= case (x .|. shiftRL x 1) of
x -> case (x .|. shiftRL x 2) of
x -> case (x .|. shiftRL x 4) of
x -> case (x .|. shiftRL x 8) of
x -> case (x .|. shiftRL x 16) of
x -> case (x .|. shiftRL x 32) of -- for 64 bit platforms
x -> (x `xor` (shiftRL x 1))
to this
highestBitMask :: Nat -> Nat
highestBitMask x0
= case (x0 .|. shiftRL x0 1) of
x1 -> case (x1 .|. shiftRL x1 2) of
x2 -> case (x2 .|. shiftRL x2 4) of
x3 -> case (x3 .|. shiftRL x3 8) of
x4 -> case (x3 .|. shiftRL x4 16) of
x5 -> case (x4 .|. shiftRL x5 32) of -- for 64 bit platforms
x6 -> (x6 `xor` (shiftRL x6 1))
If you stare at it long enough, you might find the typo. Don't cheat and look at the patch. I'll give you a hint: quickcheck won't find it because the tests don't use big enough integers.
Needless to say this completely breaks the library, and if it ain't broke... :)
Trac metadata
Trac field | Value |
---|---|
Version | 6.8.3 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries (other) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |