From fa211f3c6d27cf962b28f10e3c18b12dde4d20c3 Mon Sep 17 00:00:00 2001
From: Bram Moolenaar <Bram@vim.org>
Date: Fri, 7 Aug 2020 22:00:26 +0200
Subject: [PATCH] patch 8.2.1391: Vim9: no error for shadowing a script
 function

Problem:    Vim9: no error for shadowing a script function.
Solution:   Check for already defined items. (closes #6652)
---
 src/testdir/test_vim9_script.vim | 12 ++++++++++++
 src/version.c                    |  2 ++
 src/vim9compile.c                |  2 ++
 3 files changed, 16 insertions(+)

diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index c4a6f9a28b..3f1997f6f4 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -1780,6 +1780,18 @@ def Test_func_redefine_fails()
     enddef
   END
   CheckScriptFailure(lines, 'E1073:')
+
+  lines =<< trim END
+    vim9script
+    def Foo(): string
+      return 'foo'
+      enddef
+    def Func()
+      let  Foo = {-> 'lambda'}
+    enddef
+    defcompile
+  END
+  CheckScriptFailure(lines, 'E1073:')
 enddef
 
 def Test_fixed_size_list()
diff --git a/src/version.c b/src/version.c
index 8b68bc164d..978920e81c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1391,
 /**/
     1390,
 /**/
diff --git a/src/vim9compile.c b/src/vim9compile.c
index a6b4a27db8..25da7f562c 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -5462,6 +5462,8 @@ compile_assignment(char_u *arg, exarg_T *eap, cmdidx_T cmdidx, cctx_T *cctx)
 			semsg(_(e_unknown_var), name);
 			goto theend;
 		    }
+		    else if (check_defined(var_start, varlen, cctx) == FAIL)
+			goto theend;
 		}
 	    }
 
-- 
2.47.2