gdalbuildvrt handling of relative paths

[lpinner]

Currently gdalbuildvrt doesn't set the "relativeToVRT" attribute correctly when the output vrt is not in the same directory that the command was run from. e.g:

$ gdalbuildvrt ../test.vrt test1.tif test2.tif
$ cat ../test.vrt
<VRTDataset rasterXSize="250" rasterYSize="500">
  <GeoTransform> 0.0000000000000000e+000, 1.0000000000000000e+000, 0.0000000000000000e+000, 5.0000000000000000e+002, 0.0000000000000000e+000,-1.0000000000000000e+000</GeoTransform>
  <VRTRasterBand dataType="Byte" band="1">
    <NoDataValue>0.00000000000000E+000</NoDataValue>
    <ComplexSource>
      <SourceFilename relativeToVRT="0">test1.tif</SourceFilename>
      <SourceBand>1</SourceBand>
      <SourceProperties RasterXSize="250" RasterYSize="250" DataType="Byte" BlockXSize="256" BlockYSize="16" />
      <SrcRect xOff="0" yOff="0" xSize="250" ySize="250" />
      <DstRect xOff="0" yOff="250" xSize="250" ySize="250" />
      <NODATA>0</NODATA>
    </ComplexSource>
    <ComplexSource>
      <SourceFilename relativeToVRT="0">test2.tif</SourceFilename>
      <SourceBand>1</SourceBand>
      <SourceProperties RasterXSize="250" RasterYSize="250" DataType="Byte" BlockXSize="256" BlockYSize="16" />
      <SrcRect xOff="0" yOff="0" xSize="250" ySize="250" />
      <DstRect xOff="0" yOff="0" xSize="250" ySize="250" />
      <NODATA>0</NODATA>
    </ComplexSource>
  </VRTRasterBand>
</VRTDataset>

The obvious workaround is: gdalbuildvrt test.vrt dir/test1.tif dir/test2.tif but I often forget that :) so requesting an enhancement to handle relative paths better.