Check for null values in the PostGIS results and don't add attributes

with null values to the feature rather than adding a value based on
decoding a buffer full of undefined data.

plugins/input/postgis/postgisfs.cpp

@@ -105,57 +105,61 @@ feature_ptr postgis_featureset::next()
         for (unsigned pos=1;pos<num_attrs_+1;++pos)
         {
            std::string name = rs_->getFieldName(pos);
-           const char* buf=rs_->getValue(pos);
+
-           int oid = rs_->getTypeOID(pos);
+           if (!rs_->isNull(pos))
+           {
+              const char* buf=rs_->getValue(pos);
+              int oid = rs_->getTypeOID(pos);
            
-           if (oid==23) //int4
+              if (oid==23) //int4
-           {
-              int val = int4net(buf);
-              boost::put(*feature,name,val);
-           }
-           else if (oid==21) //int2
-           {
-              int val = int2net(buf);
-              boost::put(*feature,name,val);
-           }
-           else if (oid == 700) // float4
-           {
-              float val;
-              float4net(val,buf);
-              boost::put(*feature,name,val);
-           }
-           else if (oid == 701) // float8
-           {
-              double val;
-              float8net(val,buf);
-              boost::put(*feature,name,val);
-           }
-           else if (oid==25 || oid==1042 || oid==1043) // text or bpchar or varchar
-           {
-              //std::string str(buf);
-              //trim(str);
-              //std::wstring wstr = tr_->transcode(str);
-              UnicodeString ustr = tr_->transcode(buf);
-              boost::put(*feature,name,ustr);
-           }
-           else if (oid == 1700) // numeric
-           {
-              std::string str = numeric2string(buf);
-              try 
               {
-                 double val = boost::lexical_cast<double>(str);
+                 int val = int4net(buf);
                  boost::put(*feature,name,val);
               }
-              catch (boost::bad_lexical_cast & ex)
+              else if (oid==21) //int2
               {
-                 std::clog << ex.what() << "\n"; 
+                 int val = int2net(buf);
+                 boost::put(*feature,name,val);
               }
-           }
+              else if (oid == 700) // float4
-           else 
+              {
-           {
+                 float val;
+                 float4net(val,buf);
+                 boost::put(*feature,name,val);
+              }
+              else if (oid == 701) // float8
+              {
+                 double val;
+                 float8net(val,buf);
+                 boost::put(*feature,name,val);
+              }
+              else if (oid==25 || oid==1042 || oid==1043) // text or bpchar or varchar
+              {
+                 //std::string str(buf);
+                 //trim(str);
+                 //std::wstring wstr = tr_->transcode(str);
+                 UnicodeString ustr = tr_->transcode(buf);
+                 boost::put(*feature,name,ustr);
+              }
+              else if (oid == 1700) // numeric
+              {
+                 std::string str = numeric2string(buf);
+                 try 
+                 {
+                    double val = boost::lexical_cast<double>(str);
+                    boost::put(*feature,name,val);
+                 }
+                 catch (boost::bad_lexical_cast & ex)
+                 {
+                    std::clog << ex.what() << "\n"; 
+                 }
+              }
+              else 
+              {
 #ifdef MAPNIK_DEBUG
-              std::clog << "uknown OID = " << oid << " FIXME \n";
+                 std::clog << "uknown OID = " << oid << " FIXME \n";
 #endif
+              }
            }
         }
         ++count_;   

plugins/input/postgis/resultset.hpp

@@ -121,6 +121,11 @@ public:
 	    return PQftype(res_,col);
 	return 0;
     }
+
+    bool isNull(int index) const
+    {
+	return PQgetisnull(res_,pos_,index);
+    }
     
     const char* getValue(int index) const
     {