Debug 2

[Daniel Morissette]

John Cole wrote:
> Should setting Debug 2 and MS_ERRORFILE to stderr impact the map image?
> 
> see:
> 
> http://map.uai.com:28080/cgi-bin2/mapserv.exe?map=/mapserver/tiger/tiger5.map&LAYERS=bound%2Chydro%2Clandmark%2Croads&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&FORMAT=image%2Fjpeg&SRS=EPSG%3A4326&BBOX=-92.995609%2C31.96503%2C-82.283939%2C38.00751&WIDTH=975&HEIGHT=550
> 
> It has corruption at the bottom.
> 
> In MS 4, you could turn DEBUG ON without impacting a WMS query (though it
> did effect WFS queries).
> 

The debug output ends up in the image source:

msDrawMap(): Layer 0 (Counties), 0.094s
msDrawMap(): Layer 3 (water_poly_us_low), 1.813s
msDrawMap(): Layer 1 (landmark_poly), 0.109s
msDrawMap(): Layer 17 (ushwy_4M), 0.094s
msDrawMap(): Drawing Label Cache, 0.015s
msDrawMap() total time: 2.125s

This is a known issue with IIS where stderr goes to stdout and there 
doesn't seem to be anything we can do about this. If this worked in old 
releases then you've only been lucky that the debug output was not 
corrupting the images in a significant way, but the same issue was there.

The solution is to NOT use stderr with IIS, set MS_ERRORFILE to write to 
a file on disk instead.

Daniel
-- 
Daniel Morissette
http://www.mapgears.com/