Clear repodata->lasthandle for freed/swapped solvable

Fixes issue #377

Author: mlschroe

src/repo.c

@@ -213,6 +213,8 @@ repo_free_solvable_block(Repo *repo, Id start, int count, int reuseids)
 	      int j;
 	      for (j = dstart; j < dend; j++)	
 		data->attrs[j - data->start] = solv_free(data->attrs[j - data->start]);
+	      if (data->lasthandle >= dstart && data->lasthandle < dend)
+	        data->lasthandle = 0;
 	    }
 	  if (data->incoreoffset)
 	    memset(data->incoreoffset + (dstart - data->start), 0, (dend - dstart) * sizeof(Id));

src/repodata.c

@@ -3100,6 +3100,8 @@ repodata_swap_attrs(Repodata *data, Id dest, Id src)
   tmpattrs = data->attrs[dest - data->start];
   data->attrs[dest - data->start] = data->attrs[src - data->start];
   data->attrs[src - data->start] = tmpattrs;
+  if (data->lasthandle == src || data->lasthandle == dest)
+    data->lasthandle = 0;
 }