wxGUI AddWSDialog RenderWMSMgr: Fix render WMS jpeg source format

[tmszi]

To reproduce:

1. Click on the Add web service layer (WMS, WMTS, NASA OnEarth) toolbar icon tool
2. Set this url http://ows.mundialis.de/services/service? in the Server TextCtrl widget
3. Click on the Connect button
4. In the List of layers choose OpenStreetMap WMS - by terrestris -> default
5. On the Source image format RadioBox widget check jpeg
6. Choose proper Source projection CheckBox widget item (EPSG: 4326)
7. Click on the Add layer button

Error message (Console page):

Traceback (most recent call last):
  File "/usr/lib64/grass79/gui/wxpython/core/gthread.py",
line 121, in OnDone

event.ondone(event)
  File "/usr/lib64/grass79/gui/wxpython/core/ws.py", line
200, in OnRenderDone

self.maskMerger.AddRasterBands(self.tempMap, {4: 1})
  File "/usr/lib64/grass79/gui/wxpython/core/ws.py", line
392, in AddRasterBands

bandData = sDataset.GetRasterBand(sBandNnum).ReadRaster(
AttributeError
:
'NoneType' object has no attribute 'ReadRaster'

Error message (Terminal emulator):

ERROR 5: /home/user/grassdata/osm/PERMANENT/.tmp/gnu-linux/12160.4: GDALDataset::GetRasterBand(4) - Illegal band #

[petrasovaa]

Thank you for fixing it, could you explain the fill value 256?

[tmszi]

You are welcome. Correct value should be 255 (white color), not 256 (but every value > 255 produce white color in this case). Alright I updated it to the correct value. If mask is white color g.pnmcomp doesn't apply mask for the input map (WMS jpeg source format) and rendering is correctly.

/gui/wxpython/core/render.py, row 658

if maps:
    ret, msg = RunCommand('g.pnmcomp',
                          getErrorMsg=True,
                          overwrite=True,
                          input='%s' % ",".join(maps),
                          mask='%s' % ",".join(masks),
                          opacity='%s' % ",".join(opacities),
                          bgcolor=bgcolor,
                          width=env['GRASS_RENDER_WIDTH'],
                          height=env['GRASS_RENDER_HEIGHT'],
                          output=self.Map.mapfile,
                          env=env)