# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1609532104 -3600
# Node ID a8e7acf71fa47b68d02c8313ecd0e0053fe0cf6d
# Parent  f04821549e6f255d6a6d47134311e67bb0022183
patch 8.2.2268: Vim9: list unpack seen as declaration

Commit: https://github.com/vim/vim/commit/3862ea3f620f02569c2d816ca9ceeeac3a0ad901
Author: Bram Moolenaar <Bram@vim.org>
Date:   Fri Jan 1 21:05:55 2021 +0100

    patch 8.2.2268: Vim9: list unpack seen as declaration

    Problem:    Vim9: list unpack seen as declaration.
    Solution:   Check for "var". (closes https://github.com/vim/vim/issues/7594)

diff --git a/src/eval.c b/src/eval.c
--- a/src/eval.c
+++ b/src/eval.c
@@ -1748,7 +1748,7 @@ next_for_item(void *fi_void, char_u *arg
 {
     forinfo_T	*fi = (forinfo_T *)fi_void;
     int		result;
-    int		flag = in_vim9script() ?  ASSIGN_NO_DECL : 0;
+    int		flag = in_vim9script() ? ASSIGN_DECL : 0;
     listitem_T	*item;
 
     if (fi->fi_blob != NULL)
diff --git a/src/evalvars.c b/src/evalvars.c
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -912,7 +912,7 @@ ex_let_vars(
     int		copy,		// copy values from "tv", don't move
     int		semicolon,	// from skip_var_list()
     int		var_count,	// from skip_var_list()
-    int		flags,		// ASSIGN_FINAL, ASSIGN_CONST, ASSIGN_NO_DECL
+    int		flags,		// ASSIGN_FINAL, ASSIGN_CONST, etc.
     char_u	*op)
 {
     char_u	*arg = arg_start;
@@ -1267,7 +1267,7 @@ ex_let_one(
     char_u	*arg,		// points to variable name
     typval_T	*tv,		// value to assign to variable
     int		copy,		// copy value from "tv"
-    int		flags,		// ASSIGN_CONST, ASSIGN_FINAL, ASSIGN_NO_DECL
+    int		flags,		// ASSIGN_CONST, ASSIGN_FINAL, etc.
     char_u	*endchars,	// valid chars after variable name  or NULL
     char_u	*op)		// "+", "-", "."  or NULL
 {
@@ -1279,7 +1279,7 @@ ex_let_one(
     int		opt_flags;
     char_u	*tofree = NULL;
 
-    if (in_vim9script() && (flags & ASSIGN_NO_DECL) == 0
+    if (in_vim9script() && (flags & (ASSIGN_NO_DECL | ASSIGN_DECL)) == 0
 			&& (flags & (ASSIGN_CONST | ASSIGN_FINAL)) == 0
 				  && vim_strchr((char_u *)"$@&", *arg) != NULL)
     {
@@ -1476,7 +1476,8 @@ ex_let_one(
 	lval_T	lv;
 
 	p = get_lval(arg, tv, &lv, FALSE, FALSE,
-		(flags & ASSIGN_NO_DECL) ? GLV_NO_DECL : 0, FNE_CHECK_START);
+		(flags & (ASSIGN_NO_DECL | ASSIGN_DECL))
+					   ? GLV_NO_DECL : 0, FNE_CHECK_START);
 	if (p != NULL && lv.ll_name != NULL)
 	{
 	    if (endchars != NULL && vim_strchr(endchars,
@@ -3053,7 +3054,7 @@ set_var(
     typval_T	*tv,
     int		copy)	    // make copy of value in "tv"
 {
-    set_var_const(name, NULL, tv, copy, ASSIGN_NO_DECL);
+    set_var_const(name, NULL, tv, copy, ASSIGN_DECL);
 }
 
 /*
@@ -3067,7 +3068,7 @@ set_var_const(
     type_T	*type,
     typval_T	*tv_arg,
     int		copy,	    // make copy of value in "tv"
-    int		flags)	    // ASSIGN_CONST, ASSIGN_FINAL, ASSIGN_NO_DECL
+    int		flags)	    // ASSIGN_CONST, ASSIGN_FINAL, etc.
 {
     typval_T	*tv = tv_arg;
     typval_T	bool_tv;
@@ -3087,7 +3088,7 @@ set_var_const(
 
     if (vim9script
 	    && !is_script_local
-	    && (flags & ASSIGN_NO_DECL) == 0
+	    && (flags & (ASSIGN_NO_DECL | ASSIGN_DECL)) == 0
 	    && (flags & (ASSIGN_CONST | ASSIGN_FINAL)) == 0
 	    && name[1] == ':')
     {
@@ -3126,7 +3127,7 @@ set_var_const(
 
 	    if (is_script_local && vim9script)
 	    {
-		if ((flags & ASSIGN_NO_DECL) == 0)
+		if ((flags & (ASSIGN_NO_DECL | ASSIGN_DECL)) == 0)
 		{
 		    semsg(_(e_redefining_script_item_str), name);
 		    goto failed;
@@ -3200,8 +3201,15 @@ set_var_const(
 
 	clear_tv(&di->di_tv);
     }
-    else		    // add a new variable
+    else
     {
+	// add a new variable
+	if (vim9script && is_script_local && (flags & ASSIGN_NO_DECL))
+	{
+	    semsg(_(e_unknown_variable_str), name);
+	    goto failed;
+	}
+
 	// Can't add "v:" or "a:" variable.
 	if (ht == &vimvarht || ht == get_funccal_args_ht())
 	{
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -262,6 +262,12 @@ def Test_assign_unpack()
   CheckDefFailure(lines, 'E1031:', 3)
 
   lines =<< trim END
+      [v1, v2] = [1, 2]
+  END
+  CheckDefFailure(lines, 'E1089', 1)
+  CheckScriptFailure(['vim9script'] + lines, 'E1089', 2)
+
+  lines =<< trim END
       var v1: number
       var v2: number
       [v1, v2] = ''
@@ -759,6 +765,8 @@ def Test_assignment_default()
   assert_equal(5678, nr)
 enddef
 
+let scriptvar = 'init'
+
 def Test_assignment_var_list()
   var lines =<< trim END
       var v1: string
@@ -794,10 +802,9 @@ def Test_assignment_var_list()
       assert_equal('some', $SOME_VAR)
       assert_equal('other', $OTHER_VAR)
 
-      [g:globalvar, s:scriptvar, b:bufvar, w:winvar, t:tabvar, v:errmsg] =
-            ['global', 'script', 'buf', 'win', 'tab', 'error']
+      [g:globalvar, b:bufvar, w:winvar, t:tabvar, v:errmsg] =
+            ['global', 'buf', 'win', 'tab', 'error']
       assert_equal('global', g:globalvar)
-      assert_equal('script', s:scriptvar)
       assert_equal('buf', b:bufvar)
       assert_equal('win', w:winvar)
       assert_equal('tab', t:tabvar)
@@ -805,6 +812,21 @@ def Test_assignment_var_list()
       unlet g:globalvar
   END
   CheckDefAndScriptSuccess(lines)
+
+  [g:globalvar, s:scriptvar, b:bufvar] = ['global', 'script', 'buf']
+  assert_equal('global', g:globalvar)
+  assert_equal('script', s:scriptvar)
+  assert_equal('buf', b:bufvar)
+
+  lines =<< trim END
+      vim9script
+      var s:scriptvar = 'init'
+      [g:globalvar, s:scriptvar, w:winvar] = ['global', 'script', 'win']
+      assert_equal('global', g:globalvar)
+      assert_equal('script', s:scriptvar)
+      assert_equal('win', w:winvar)
+  END
+  CheckScriptSuccess(lines)
 enddef
 
 def Test_assignment_vim9script()
@@ -1182,7 +1204,7 @@ def Test_var_declaration()
     g:other_var = other
 
     # type is inferred
-    s:dict = {['a']: 222}
+    var s:dict = {['a']: 222}
     def GetDictVal(key: any)
       g:dict_val = s:dict[key]
     enddef
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2268,
+/**/
     2267,
 /**/
     2266,
diff --git a/src/vim.h b/src/vim.h
--- a/src/vim.h
+++ b/src/vim.h
@@ -2146,6 +2146,7 @@ typedef enum {
 #define ASSIGN_FINAL	1   // ":final"
 #define ASSIGN_CONST	2   // ":const"
 #define ASSIGN_NO_DECL	4   // "name = expr" without ":let"/":const"/":final"
+#define ASSIGN_DECL	8   // may declare variable if it does not exist
 
 #include "ex_cmds.h"	    // Ex command defines
 #include "spell.h"	    // spell checking stuff
diff --git a/src/vim9compile.c b/src/vim9compile.c
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -5634,6 +5634,11 @@ compile_assignment(char_u *arg, exarg_T 
 		semsg(_(e_cannot_use_operator_on_new_variable), name);
 		goto theend;
 	    }
+	    if (!is_decl)
+	    {
+		semsg(_(e_unknown_variable_str), name);
+		goto theend;
+	    }
 
 	    // new local variable
 	    if ((type->tt_type == VAR_FUNC || type->tt_type == VAR_PARTIAL)
@@ -6140,6 +6145,7 @@ compile_unletlock(char_u *arg, exarg_T *
 	return NULL;
     }
 
+    // TODO: this doesn't work for local variables
     ex_unletlock(eap, p, 0, GLV_NO_AUTOLOAD, compile_unlet, cctx);
     return eap->nextcmd == NULL ? (char_u *)"" : eap->nextcmd;
 }
diff --git a/src/vim9execute.c b/src/vim9execute.c
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -806,7 +806,7 @@ store_var(char_u *name, typval_T *tv)
     funccal_entry_T entry;
 
     save_funccal(&entry);
-    set_var_const(name, NULL, tv, FALSE, ASSIGN_NO_DECL);
+    set_var_const(name, NULL, tv, FALSE, ASSIGN_DECL);
     restore_funccal();
 }