patch 8.2.1382: Vim9: using :import in filetype plugin gives an error

Problem:    Vim9: using :import in filetype plugin gives an error.
Solution:   Allow commands with the EX_LOCK_OK flag. (closes #6636)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 105710b..96eac7f 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -2087,7 +2087,7 @@
 	// Do allow ":checktime" (it is postponed).
 	// Do allow ":edit" (check for an argument later).
 	// Do allow ":file" with no arguments (check for an argument later).
-	if (!(ea.argt & EX_CMDWIN)
+	if (!(ea.argt & (EX_CMDWIN | EX_LOCK_OK))
 		&& ea.cmdidx != CMD_checktime
 		&& ea.cmdidx != CMD_edit
 		&& ea.cmdidx != CMD_file
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index b05cd54..e5d5e87 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -1381,6 +1381,36 @@
   nunmap trigger
 enddef
 
+def Test_import_in_filetype()
+  # check that :import works when the buffer is locked
+  mkdir('ftplugin', 'p')
+  let export_lines =<< trim END
+    vim9script
+    export let That = 'yes'
+  END
+  writefile(export_lines, 'ftplugin/Xexport_that.vim')
+
+  let import_lines =<< trim END
+    vim9script
+    import That from './Xexport_that.vim'
+    assert_equal('yes', That)
+    g:did_load_mytpe = 1
+  END
+  writefile(import_lines, 'ftplugin/qf.vim')
+
+  let save_rtp = &rtp
+  &rtp = getcwd() .. ',' .. &rtp
+
+  filetype plugin on
+  copen
+  assert_equal(1, g:did_load_mytpe)
+
+  quit!
+  delete('Xexport.vim')
+  delete('ftplugin', 'rf')
+  &rtp = save_rtp
+enddef
+
 def Test_vim9script_fails()
   CheckScriptFailure(['scriptversion 2', 'vim9script'], 'E1039:')
   CheckScriptFailure(['vim9script', 'scriptversion 2'], 'E1040:')
diff --git a/src/version.c b/src/version.c
index 3d7c5b1..5c745df 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1382,
+/**/
     1381,
 /**/
     1380,