Fix "tmp not defined" in exportimagepixels!() (#176)

Author: alyst

src/libmagickwand.jl

@@ -209,11 +209,12 @@ bitdepth(buffer::AbstractArray{C}) where {C<:Colorant} = 8*sizeof(eltype(C))
 bitdepth(buffer::AbstractArray{T}) where {T} = 8*sizeof(T)
 
 # colorspace is included for consistency with constituteimage, but it is not used
-function exportimagepixels!(@nospecialize(buffer::AbstractArray{<:Union{Unsigned,Bool}}), wand::MagickWand,  colorspace::String, channelorder::String; x = 0, y = 0)
+function exportimagepixels!(@nospecialize(buffer::AbstractArray{<:Union{Unsigned,Bool}}), wand::MagickWand, colorspace::String, channelorder::String; x = 0, y = 0)
     T = eltype(buffer)
     cols, rows, nimages = getsize(buffer, channelorder)
     ncolors = colorsize(buffer, channelorder)
     if isa(buffer, Array)
+        tmp = nothing
         p = pointer(buffer)
     else
         tmp = similar(buffer)
@@ -225,7 +226,7 @@ function exportimagepixels!(@nospecialize(buffer::AbstractArray{<:Union{Unsigned
         status == 0 && error(wand)
         p += sizeof(T)*cols*rows*ncolors
     end
-    isa(buffer, Array) || buffer .= tmp
+    isa(buffer, Array) || (buffer .= tmp)
     buffer
 end
 

test/constructed_images.jl

@@ -301,4 +301,30 @@ mutable struct TestType end
         B = ImageMagick.load(fn, true)
         @test transpose(A)==B
     end
+
+    @testset "exportimagepixels!()" begin
+        # test the direct use of exportimagepixels!()
+        Ar = [0x10 0xff 0x80; 0x00 0x00 0x20]
+        A = Gray.(N0f8.(Ar, 0))
+        fn = joinpath(workdir, "2d.tif")
+        ImageMagick.save(fn, A, false)
+
+        wand = MagickWand()
+        readimage(wand, fn)
+        @test ImageMagick.getnumberimages(wand) == 1
+        ImageMagick.resetiterator(wand)
+        sz, T, cs, channelorder = ImageMagick._metadata(wand)
+        @test sz == size(Ar)
+        @test T == Gray{N0f8}
+        # test using the array
+        buf = Array{UInt8}(undef, sz)
+        exportimagepixels!(buf, wand, cs, channelorder)
+        @test buf == Ar
+
+        # test using the subarray
+        buf2 = similar(buf, ntuple(i -> i <= length(sz) ? sz[i] + 1 : 2, length(sz) + 1))
+        buf2view = view(buf2, 1:sz[1], 1:sz[2], 2)
+        exportimagepixels!(buf2view, wand, cs, channelorder)
+        @test buf2view == Ar
+    end
 end