[virtual layer] Fix xFilter for null value comparisons

Hugo Mercier · Hugo Mercier · commit 89461909d3a7 · 2016-12-05T10:02:53.000+01:00
diff --git a/src/providers/virtual/qgsvirtuallayersqlitemodule.cpp b/src/providers/virtual/qgsvirtuallayersqlitemodule.cpp
@@ -624,13 +624,13 @@ int vtableFilter( sqlite3_vtab_cursor * cursor, int idxNum, const char *idxStr,
         expr += "'" + str.replace( QLatin1String( "'" ), QLatin1String( "''" ) ) + "'";
         break;
       }
+      case SQLITE_NULL:
+      case SQLITE_BLOB: // comparison to blob ignored
       default:
-        expr = QLatin1String( "" );
-    }
-    if ( !expr.isEmpty() )
-    {
-      request.setFilterExpression( expr );
+        expr += QLatin1String( " is null" );
+        break;
     }
+    request.setFilterExpression( expr );
   }
   VTableCursor *c = reinterpret_cast<VTableCursor*>( cursor );
   c->filter( request );

Original file line number	Diff line number	Diff line change
`@@ -624,13 +624,13 @@ int vtableFilter( sqlite3_vtab_cursor * cursor, int idxNum, const char *idxStr,`
`624`	`624`	`expr += "'" + str.replace( QLatin1String( "'" ), QLatin1String( "''" ) ) + "'";`
`625`	`625`	`break;`
`626`	`626`	`}`
	`627`	`+ case SQLITE_NULL:`
	`628`	`+ case SQLITE_BLOB: // comparison to blob ignored`
`627`	`629`	`default:`
`628`		`- expr = QLatin1String( "" );`
`629`		`- }`
`630`		`- if ( !expr.isEmpty() )`
`631`		`- {`
`632`		`- request.setFilterExpression( expr );`
	`630`	`+ expr += QLatin1String( " is null" );`
	`631`	`+ break;`
`633`	`632`	`}`
	`633`	`+ request.setFilterExpression( expr );`
`634`	`634`	`}`
`635`	`635`	`VTableCursor c = reinterpret_cast<VTableCursor>( cursor );`
`636`	`636`	`c->filter( request );`