Incorrect empty style name handling on WMS STYLES parameter

[aeichner]

According to the WMS spec using an empty style name in the STYLES parameter should be treated as "default". But using a request with ...&layers=a,b,c&styles=a,,&... fails with "[...] Mapserver is expecting an empty string for the STYLES [...]".

The problem seems to be in msWMSLoadGetMapParams() where the msStringSplit() is used which throws empty tokens away. The following patch uses msStringSplitComplex() with the ALLOWEMPTYTOKENS flag set and seems to solve that problem:

diff --git a/mapwms.c b/mapwms.c
index d02c667..037441b 100644
--- a/mapwms.c
+++ b/mapwms.c
@@ -1108,7 +1108,7 @@ int msWMSLoadGetMapParams(mapObj *map, int nVersion,
       int numlayers =0;
       layerObj *lp = NULL;

-      tokens = msStringSplit(styles, ',' ,&n);
+      tokens = msStringSplitComplex(styles, ","
,&n,MS_ALLOWEMPTYTOKENS);
       for (i=0; i<n; i++)
       {
           if (tokens[i] && strlen(tokens[i]) > 0 && 

[sdlime]

Seems a reasonable change. Alan, what do you think? Steve

[tbonfort]

cc @aboudreault