Triplanar with different colorspaces gets wrong color transform

[rasmusbonnedal]

Description

When using the <triplanarprojection> node (which has 3 filename inputs) and different colorspaces on the different inputs only one colorspace transform is generated.

To reproduce

Create a <triplanarprojection> node with different colorspaces on the different input and observe the generated OSL code.

repro-triplanar.zip

Result

Generated OSL code:

    NG_triplanarprojection_color3(triplanarprojection_filex_, triplanarprojection_filey_, triplanarprojection_filez_, triplanarprojection_layerx, triplanarprojection_layery, triplanarprojection_layerz, triplanarprojection_default, geomprop_Pobject_out1, geomprop_Nobject_out1, triplanarprojection_upaxis, triplanarprojection_blend, triplanarprojection_filtertype, triplanarprojection_framerange, triplanarprojection_frameoffset, triplanarprojection_frameendaction, triplanarprojection_out);
    color triplanarprojection_out_cm_out = color(0.0);
    NG_srgb_texture_to_lin_rec709_color3(triplanarprojection_out, triplanarprojection_out_cm_out);

Expected result

I'd expect that three colorspace transforms would be emitted, one for each file input, with the corresponding source colorspace for each file input.