patch 8.2.3411: Vim9: crash when using base name of import

Problem:    Vim9: crash when using base name of import. (Naohiro Ono)
Solution:   Check the import flags. (closes vim#8843)

src/errors.h

@@ -654,3 +654,5 @@ EXTERN char e_legacy_must_be_followed_by_command[]
 	INIT(= N_("E1234: legacy must be followed by a command"));
 EXTERN char e_function_reference_is_not_set[]
 	INIT(= N_("E1235: Function reference is not set"));
+EXTERN char e_cannot_use_str_itself_it_is_imported_with_star[]
+	INIT(= N_("E1236: Cannot use %s itself, it is imported with '*'"));

src/evalvars.c

@@ -3260,6 +3260,12 @@ set_var_const(
 		semsg(_(e_redefining_imported_item_str), name);
 		goto failed;
 	    }
+	    if (import->imp_flags & IMP_FLAGS_STAR)
+	    {
+		semsg(_(e_cannot_use_str_itself_it_is_imported_with_star),
+									 name);
+		goto failed;
+	    }
 	    sv = ((svar_T *)si->sn_var_vals.ga_data) + import->imp_var_vals_idx;
 
 	    where.wt_variable = TRUE;

src/testdir/test_vim9_script.vim

@@ -1477,6 +1477,21 @@ def Test_vim9_import_export()
   delete('Xvim9_script')
 enddef
 
+def Test_import_star_fails()
+  writefile([], 'Xfoo.vim')
+  var lines =<< trim END
+      import * as foo from '/tmp/foo.vim'
+      foo = 'bar'
+  END
+  CheckDefAndScriptFailure2(lines, 'E1094:', 'E1236: Cannot use foo itself')
+  lines =<< trim END
+      vim9script
+      import * as foo from '/tmp/foo.vim'
+      var that = foo
+  END
+  CheckScriptFailure(lines, 'E1029: Expected ''.''')
+enddef
+
 def Test_import_as()
   var export_lines =<< trim END
     vim9script

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3411,
 /**/
     3410,
 /**/