Bugfix: when saving a project and there is insufficient space on the volume, handle the problem gracefully. Also fixed qgisapp so that failed project saving before app exiting halts app exit properly

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@9456 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: timlinux

src/app/qgisapp.cpp

@@ -3133,13 +3133,15 @@ bool QgisApp::fileSave()
       QMessageBox::critical( this,
                              tr( "Unable to save project" ),
                              tr( "Unable to save project to " ) + QgsProject::instance()->fileName() );
+      return false;
     }
   }
   catch ( std::exception & e )
   {
     QMessageBox::critical( this,
                            tr( "Unable to save project " ) + QgsProject::instance()->fileName(),
                            QString::fromLocal8Bit( e.what() ) );
+    return false;
   }
   return true;
 } // QgisApp::fileSave

src/core/qgsproject.cpp

@@ -1015,6 +1015,18 @@ bool QgsProject::write()
   doc->save( projectFileStream, 4 );  // save as utf-8
   imp_->file.close();
 
+  // check if the text stream had no error - if it does
+  // the user will get a message so they can try to resolve the 
+  // situation e.g. by saving project to a volume with more space
+  //
+  if ( projectFileStream.pos() == -1  || imp_->file.error() != QFile::NoError)
+  {
+    throw QgsIOException( QObject::tr( "Unable to save to file. Your project "
+          "may be corrupted on disk. Try clearing some space on the volume and "
+          "check file permissions before pressing save again." ) +
+        imp_->file.fileName() );
+    return false;
+  }
 
   dirty( false );               // reset to pristine state