Fix #7420 – indexing a FloatRange with an OrdinalRange.

base/range.jl

@@ -271,8 +271,9 @@ function getindex(r::StepRange, s::Range{Int})
 end
 
 function getindex(r::FloatRange, s::OrdinalRange)
-    0 < last(s) <= length(r) || throw(BoundsError())
-    FloatRange(r[first(s)],step(r)*step(s),length(s),r.divisor)
+    isempty(s) || 1 <= first(s) <= length(r) &&
+                  1 <=  last(s) <= length(r) || throw(BoundsError())
+    FloatRange(r.start + (first(s)-1)*r.step, step(s)*r.step, length(s), r.divisor)
 end
 
 function show(io::IO, r::Range)

test/ranges.jl

@@ -232,7 +232,16 @@ for T = (Float32, Float64,),# BigFloat),
     start = convert(T,a)/den
     step  = convert(T,s)/den
     stop  = convert(T,(a+(n-1)*s))/den
-    @test [start:step:stop] == T[a:s:a+(n-1)*s]./den
+    r = start:step:stop
+    @test [r] == T[a:s:a+(n-1)*s]./den
+    # issue #7420
+    n = length(r)
+    @test [r[1:n]] == [r]
+    @test [r[2:n]] == [r][2:end]
+    @test [r[1:3:n]] == [r][1:3:n]
+    @test [r[2:2:n]] == [r][2:2:n]
+    @test [r[n:-1:2]] == [r][n:-1:2]
+    @test [r[n:-2:1]] == [r][n:-2:1]
 end
 
 # near-equal ranges