Fixed: after ":ownsyntax perl" and ":e" syntax was cleared in other window.
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index f05a065..2ffaa3e 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -3571,6 +3571,9 @@
new_name = NULL;
#endif
buf_freeall(curbuf, FALSE, FALSE); /* free all things for buffer */
+#ifdef FEAT_SYN_HL
+ reset_synblock(curwin); /* remove any ownsyntax */
+#endif
#ifdef FEAT_AUTOCMD
/* If autocommands deleted the buffer we were going to re-edit, give
* up and jump to the end. */