fixed bug in compose for two Dicts

src/PermPlain.jl

@@ -43,6 +43,7 @@ function sparsetocycles{T}(sp::Dict{T,T})
  ks = collect(keys(sp))
  n = length(ks)
  seen = Dict{T,Bool}()
+# println("keys are $ks")
  for k in ks seen[k] = false end
  k = ks[1]
  nseen = 0
@@ -216,6 +217,7 @@ end
 
 cyclelengths{T<:Real}(c::AbstractArray{Array{T,1},1}) = [length(x) for x in c]
 
+# Likely has same bug that sparsetocycles had
 function cyclelengths{T}(sp::Dict{T,T})
  cyclens = Array(Int,0)
  isempty(sp) && return cyclens
@@ -329,12 +331,19 @@ end
 
 function permcompose{T<:Real, V<:Real}(q::Dict{T,T}, p::Dict{V,V})
  dout = Dict{T,T}()
- maxk = zero(T) 
- for (k,v) in p
- qv = get(q,v,zero(T))
- k == qv ? continue : nothing # ignore 1-cycles
- dout[k] = (qv == zero(T) ? v : qv)
- qv > maxk ? maxk = qv : nothing
+ z = zero(T)
+ maxk = z
+ seen = Dict{T,Bool}()
+ for k in keys(q) seen[k] = false end # wasteful!
+ for (k,pofk) in p
+ qofpofk = get(q,pofk,z)
+ seen[pofk] = true
+ k == qofpofk ? continue : nothing # ignore 1-cycles
+ dout[k] = (qofpofk == z ? pofk : qofpofk)
+ qofpofk > maxk ? maxk = qofpofk : nothing
+ end
+ for j in keys(q)
+ seen[j] ? nothing : dout[j] = q[j]
  end
  return dout, maxk
 end