From Colin McDonald, fixed image size calculation in getTotalSizeInBytesIncludingMipmaps(),

added checks on success of opening files for writing in the .ive plugin.

src/osgPlugins/ive/ReaderWriterIVE.cpp

@@ -82,6 +82,8 @@ class IVEReaderWriter : public ReaderWriter
                 local_opt->setDatabasePath(osgDB::getFilePath(fileName));
 
             std::ofstream fout(fileName.c_str(), std::ios::out | std::ios::binary);
+	    if (!fout) return WriteResult::ERROR_IN_WRITING_FILE;
+	    
             WriteResult result = writeNode(node, fout, local_opt.get());
             fout.close();
             return result;
@@ -103,6 +105,9 @@ class IVEReaderWriter : public ReaderWriter
                 out.setOptions(options);
 
                 out.writeNode(const_cast<osg::Node*>(&node));
+
+    	    	if ( fout.fail() ) return WriteResult::ERROR_IN_WRITING_FILE;
+
                 return WriteResult::FILE_SAVED;
             }
             catch(ive::Exception e)