Mask for overlapped layers masks both of them

[drnextgis]

I'd like to mosaic two overlapped rasters with VRT (see attachments). Both of them has a mask. But result looks like this. Is it expected result?

gdalbuildvrt -input_file_list list.txt output.vrt

overlapped-rasters.zip

[rouault]

"expected" yes as some famous CPU founder claims that their chips work as intended despite having security holes :-)
So more seriously VRT doesn't do alpha-compositing. It just takes the alpha component of the last-appearing source.
gdalwarp is currently the tool to get the effect you want (so in a non virtual way)

[drnextgis]

In this particular case these rasters don't have an alpha bands but GDAL mask. Does it behave the same? I tried to create alpha band out of a mask with gdalwarp but faced with a problem, that I reported here #794