From: Yegappan Lakshmanan <yegappan@yahoo.com>
Date: Tue, 6 Jan 2026 10:13:02 +0000 (+0000)
Subject: patch 9.1.2054: Can't unpack tuple from imported function
X-Git-Tag: v9.1.2054^0
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eb577f9206f621ea77dae175e2af1b0f0a65852f;p=thirdparty%2Fvim.git

patch 9.1.2054: Can't unpack tuple from imported function

Problem:  Can't unpack tuple from imported function
          (Mao-Yining)
Solution: Support multi-variable assignment from a tuple returned by an
          imported function (Yegappan Lakshmanan)

fixes:  #19080
closes: #19083

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
---

diff --git a/src/evalfunc.c b/src/evalfunc.c
index 5aeca60d48..e67f727d25 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -229,7 +229,7 @@ check_arg_type(
 	type_T		*actual,
 	argcontext_T	*context)
 {
-    return need_type(actual, expected, FALSE,
+    return need_type(actual, expected, 0,
 	    context->arg_idx - context->arg_count, context->arg_idx + 1,
 	    context->arg_cctx, FALSE, FALSE);
 }
@@ -243,7 +243,7 @@ check_arg_type_mod(
 	type_T		*actual,
 	argcontext_T	*context)
 {
-    if (need_type(actual, expected, FALSE,
+    if (need_type(actual, expected, 0,
 	    context->arg_idx - context->arg_count, context->arg_idx + 1,
 	    context->arg_cctx, FALSE, FALSE) == FAIL)
 	return FAIL;
diff --git a/src/proto/vim9compile.pro b/src/proto/vim9compile.pro
index 6d91bc86a0..e8b9cdd197 100644
--- a/src/proto/vim9compile.pro
+++ b/src/proto/vim9compile.pro
@@ -6,8 +6,8 @@ int script_var_exists(char_u *name, size_t len, cctx_T *cctx, cstack_T *cstack);
 int cctx_class_method_idx(cctx_T *cctx, char_u *name, size_t len, class_T **cl_ret);
 int cctx_class_member_idx(cctx_T *cctx, char_u *name, size_t len, class_T **cl_ret);
 int check_defined(char_u *p, size_t len, cctx_T *cctx, cstack_T *cstack, int is_arg);
-int need_type_where(type_T *actual, type_T *expected, int number_ok, int offset, where_T where, cctx_T *cctx, int silent, int actual_is_const);
-int need_type(type_T *actual, type_T *expected, int number_ok, int offset, int arg_idx, cctx_T *cctx, int silent, int actual_is_const);
+int need_type_where(type_T *actual, type_T *expected, int typechk_flags, int offset, where_T where, cctx_T *cctx, int silent, int actual_is_const);
+int need_type(type_T *actual, type_T *expected, int typechk_flags, int offset, int arg_idx, cctx_T *cctx, int silent, int actual_is_const);
 lvar_T *reserve_local(cctx_T *cctx, char_u *name, size_t len, int assign, type_T *type);
 int get_script_item_idx(int sid, char_u *name, int check_writable, cctx_T *cctx, cstack_T *cstack);
 imported_T *find_imported(char_u *name, size_t len, int load);
diff --git a/src/proto/vim9instr.pro b/src/proto/vim9instr.pro
index a4504c5137..f4b587d8cb 100644
--- a/src/proto/vim9instr.pro
+++ b/src/proto/vim9instr.pro
@@ -16,7 +16,7 @@ int generate_COMPARE(cctx_T *cctx, exprtype_T exprtype, int ic);
 int generate_CONCAT(cctx_T *cctx, int count);
 int generate_2BOOL(cctx_T *cctx, int invert, int offset);
 int generate_COND2BOOL(cctx_T *cctx);
-int generate_TYPECHECK(cctx_T *cctx, type_T *expected, int number_ok, int offset, int is_var, int argidx);
+int generate_TYPECHECK(cctx_T *cctx, type_T *expected, int typechk_flags, int offset, int is_var, int argidx);
 int generate_SETTYPE(cctx_T *cctx, type_T *expected);
 int generate_PUSHOBJ(cctx_T *cctx);
 int generate_tv_PUSH(cctx_T *cctx, typval_T *tv);
diff --git a/src/structs.h b/src/structs.h
index 6513f2b894..6df682307b 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1532,7 +1532,7 @@ struct type_S {
     vartype_T	    tt_type;
     int8_T	    tt_argcount;    // for func, incl. vararg, -1 for unknown
     int8_T	    tt_min_argcount; // number of non-optional arguments
-    char_u	    tt_flags;	    // TTFLAG_ values
+    short_u	    tt_flags;	    // TTFLAG_ values
     type_T	    *tt_member;	    // for list, dict, func return type
     class_T	    *tt_class;	    // for class and object
     type_T	    **tt_args;	    // func argument types, allocated
@@ -1551,10 +1551,15 @@ typedef struct {
 #define TTFLAG_CONST	    0x20    // cannot be changed
 #define TTFLAG_SUPER	    0x40    // object from "super".
 #define TTFLAG_GENERIC	    0x80    // generic type
+#define TTFLAG_TUPLE_OK	    0x100   // tuple can be used for a list
 
 #define IS_GENERIC_TYPE(type)	\
     ((type->tt_flags & TTFLAG_GENERIC) == TTFLAG_GENERIC)
 
+// Type check flags
+#define TYPECHK_NUMBER_OK	0x1	// number is accepted for a float
+#define TYPECHK_TUPLE_OK	0x2	// tuple is accepted for a list
+
 typedef enum {
     VIM_ACCESS_PRIVATE,	// read/write only inside the class
     VIM_ACCESS_READ,	// read everywhere, write only inside the class
diff --git a/src/testdir/test_tuple.vim b/src/testdir/test_tuple.vim
index 1d87fe1194..191546a5e4 100644
--- a/src/testdir/test_tuple.vim
+++ b/src/testdir/test_tuple.vim
@@ -2356,4 +2356,103 @@ func Test_tuple2list()
   call v9.CheckSourceDefAndScriptSuccess(lines)
 endfunc
 
+" Test for assigning multiple variables (list assign) using an imported
+" function returning a tuple.
+func Test_tuple_multi_assign_from_import()
+  let lines =<< trim END
+    vim9script
+
+    export def Fn(): tuple<string, string>
+      return ('aaa', 'bbb')
+    enddef
+  END
+  call writefile(lines, 'Ximporttuplefunc.vim', 'D')
+
+  let lines =<< trim END
+    vim9script
+
+    import "./Ximporttuplefunc.vim" as Xtuple
+
+    def XtestTupleListAssign()
+      const [x, y] = Xtuple.Fn()
+      assert_equal(['aaa', 'bbb'], [x, y])
+    enddef
+    XtestTupleListAssign()
+
+    # Check the generated code
+    def XtestTupleListAssign2()
+      const [x, y] = Xtuple.Fn()
+    enddef
+    var res = execute('disass XtestTupleListAssign2')
+    assert_match('<SNR>\d*_XtestTupleListAssign2\_s*' ..
+          'const \[x, y\] = Xtuple.Fn()\_s*' ..
+          '0 PUSHFUNC "<80><fd>R\d\+_Fn"\_s*' ..
+          '1 PCALL top (argc 0)\_s*' ..
+          '2 PCALL end\_s*' ..
+          '3 CHECKTYPE list<any>|tuple<any> stack\[-1\]\_s*' ..
+          '4 CHECKLEN 2\_s*' ..
+          '5 ITEM 0\_s*' ..
+          '6 LOCKCONST\_s*' ..
+          '7 STORE $0\_s*' ..
+          '8 ITEM 1\_s*' ..
+          '9 LOCKCONST\_s*' ..
+          '10 STORE $1\_s*' ..
+          '11 DROP\_s*' ..
+          '12 RETURN void',
+          res)
+  END
+  call v9.CheckSourceScriptSuccess(lines)
+endfunc
+
+" Test for assigning multiple variables in a for loop using an imported
+" function returning a tuple.
+func Test_tuple_multi_assign_in_for_loop_from_import()
+  let lines =<< trim END
+    vim9script
+
+    export def Fn(): tuple<...list<tuple<string, string>>>
+      return (('a', 'b'), ('c', 'd'))
+    enddef
+  END
+  call writefile(lines, 'Ximporttupleinfor.vim', 'D')
+
+  let lines =<< trim END
+    vim9script
+
+    import "./Ximporttupleinfor.vim" as Xtuple
+
+    def XtestTupleInFor()
+      var s = ''
+      for [x, y] in Xtuple.Fn()
+        s ..= x .. y
+      endfor
+      assert_equal('abcd', s)
+    enddef
+    XtestTupleInFor()
+
+    # Check the generated code
+    def XtestTupleInFor2()
+      for [x, y] in Xtuple.Fn()
+      endfor
+    enddef
+    var res = execute('disass XtestTupleInFor2')
+    assert_match('<SNR>\d*_XtestTupleInFor2\_s*' ..
+          'for \[x, y\] in Xtuple.Fn()\_s*' ..
+          '0 STORE -1 in $0\_s*' ..
+          '1 PUSHFUNC "<80><fd>R\d\+_Fn"\_s*' ..
+          '2 PCALL top (argc 0)\_s*' ..
+          '3 PCALL end\_s*' ..
+          '4 FOR $0 -> 9\_s*' ..
+          '5 UNPACK 2\_s*' ..
+          '6 STORE $2\_s*' ..
+          '7 STORE $3\_s*' ..
+          'endfor\_s*' ..
+          '8 JUMP -> 4\_s*' ..
+          '9 DROP\_s*' ..
+          '10 RETURN void',
+          res)
+  END
+  call v9.CheckSourceScriptSuccess(lines)
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
index c05381fb16..f48f7a23c1 100644
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -647,7 +647,7 @@ def Test_disassemble_list_assign()
         '\d STORE $2\_s*' ..
         '\[x, y; l\] = g:stringlist\_s*' ..
         '\d LOADG g:stringlist\_s*' ..
-        '\d CHECKTYPE list<any> stack\[-1\]\_s*' ..
+        '\d CHECKTYPE list<any>|tuple<any> stack\[-1\]\_s*' ..
         '\d CHECKLEN >= 2\_s*' ..
         '\d\+ ITEM 0\_s*' ..
         '\d\+ CHECKTYPE string stack\[-1\] var 1\_s*' ..
diff --git a/src/testdir/test_vim9_generics.vim b/src/testdir/test_vim9_generics.vim
index 48b31b043c..9aadd99cfd 100644
--- a/src/testdir/test_vim9_generics.vim
+++ b/src/testdir/test_vim9_generics.vim
@@ -2064,7 +2064,7 @@ def Test_generic_function_disassemble()
     '5 STORE $1\_s*' ..
     '\[x, y\] = g:values\_s*' ..
     '6 LOADG g:values\_s*\_s*' ..
-    '7 CHECKTYPE list<any> stack\[-1\]\_s*' ..
+    '7 CHECKTYPE list<any>|tuple<any> stack\[-1\]\_s*' ..
     '8 CHECKLEN 2\_s*' ..
     '9 ITEM 0\_s*' ..
     '10 CHECKTYPE list<string> stack\[-1\] var 1\_s*' ..
@@ -2201,7 +2201,7 @@ def Test_generic_disassemble_generic_obj_method()
     '5 STORE $2\_s*' ..
     '\[x, y\] = g:values\_s*' ..
     '6 LOADG g:values\_s*' ..
-    '7 CHECKTYPE list<any> stack\[-1\]\_s*' ..
+    '7 CHECKTYPE list<any>|tuple<any> stack\[-1\]\_s*' ..
     '8 CHECKLEN 2\_s*' ..
     '9 ITEM 0\_s*' ..
     '10 CHECKTYPE list<string> stack\[-1\] var 1\_s*' ..
@@ -2329,7 +2329,7 @@ def Test_generic_disassemble_generic_class_method()
     '5 STORE $1\_s*' ..
     '\[x, y\] = g:values\_s*' ..
     '6 LOADG g:values\_s*' ..
-    '7 CHECKTYPE list<any> stack\[-1\]\_s*' ..
+    '7 CHECKTYPE list<any>|tuple<any> stack\[-1\]\_s*' ..
     '8 CHECKLEN 2\_s*' ..
     '9 ITEM 0\_s*' ..
     '10 CHECKTYPE list<string> stack\[-1\] var 1\_s*' ..
diff --git a/src/version.c b/src/version.c
index a9c9d0544b..2f0b907699 100644
--- a/src/version.c
+++ b/src/version.c
@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2054,
 /**/
     2053,
 /**/
diff --git a/src/vim9cmds.c b/src/vim9cmds.c
index 8a1ab80cd9..be9c67be69 100644
--- a/src/vim9cmds.c
+++ b/src/vim9cmds.c
@@ -1172,7 +1172,7 @@ compile_for(char_u *arg_start, cctx_T *cctx)
 		if (lhs_type == &t_any)
 		    lhs_type = item_type;
 		else if (item_type != &t_unknown
-			&& need_type_where(item_type, lhs_type, FALSE, -1,
+			&& need_type_where(item_type, lhs_type, 0, -1,
 					    where, cctx, FALSE, FALSE) == FAIL)
 		    goto failed;
 		var_lvar = reserve_local(cctx, arg, varlen, ASSIGN_FINAL,
@@ -2625,7 +2625,7 @@ compile_redir(char_u *line, exarg_T *eap, cctx_T *cctx)
 	if (compile_assign_lhs(arg, lhs, CMD_redir,
 					 FALSE, FALSE, FALSE, 1, cctx) == FAIL)
 	    return NULL;
-	if (need_type(&t_string, lhs->lhs_member_type, FALSE,
+	if (need_type(&t_string, lhs->lhs_member_type, 0,
 					    -1, 0, cctx, FALSE, FALSE) == FAIL)
 	    return NULL;
 	if (cctx->ctx_skip == SKIP_YES)
@@ -2707,7 +2707,7 @@ compile_return(char_u *arg, int check_return_type, int legacy, cctx_T *cctx)
 	    int save_flags = cmdmod.cmod_flags;
 
 	    generate_LEGACY_EVAL(cctx, p);
-	    if (need_type(&t_any, cctx->ctx_ufunc->uf_ret_type, FALSE, -1,
+	    if (need_type(&t_any, cctx->ctx_ufunc->uf_ret_type, 0, -1,
 						0, cctx, FALSE, FALSE) == FAIL)
 		return NULL;
 	    cmdmod.cmod_flags |= CMOD_LEGACY;
@@ -2738,7 +2738,7 @@ compile_return(char_u *arg, int check_return_type, int legacy, cctx_T *cctx)
 	    }
 	    else
 	    {
-		if (need_type(stack_type, cctx->ctx_ufunc->uf_ret_type, FALSE,
+		if (need_type(stack_type, cctx->ctx_ufunc->uf_ret_type, 0,
 					    -1, 0, cctx, FALSE, FALSE) == FAIL)
 		    return NULL;
 	    }
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 1b3c7360ae..b80eb346e2 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -526,12 +526,16 @@ use_typecheck(type_T *actual, type_T *expected)
  * - return FAIL.
  * If "actual_is_const" is TRUE then the type won't change at runtime, do not
  * generate a TYPECHECK.
+ * If "typechk_flags" has TYPECHK_NUMBER_OK, then a number is accepted for
+ * a float.
+ * If "typechk_flags" has TYPECHK_TUPLE_OK, then a tuple is accepted for a
+ * list.
  */
     int
 need_type_where(
 	type_T	*actual,
 	type_T	*expected,
-	int	number_ok,	// expect VAR_FLOAT but VAR_NUMBER is OK
+	int	typechk_flags,	// acceptable types (type check flags)
 	int	offset,
 	where_T	where,
 	cctx_T	*cctx,
@@ -567,7 +571,7 @@ need_type_where(
     // If the actual type can be the expected type add a runtime check.
     if (!actual_is_const && ret == MAYBE && use_typecheck(actual, expected))
     {
-	generate_TYPECHECK(cctx, expected, number_ok, offset,
+	generate_TYPECHECK(cctx, expected, typechk_flags, offset,
 		where.wt_kind == WT_VARIABLE, where.wt_index);
 	return OK;
     }
@@ -581,7 +585,7 @@ need_type_where(
 need_type(
 	type_T	*actual,
 	type_T	*expected,
-	int	number_ok,  // when expected is float number is also OK
+	int	typechk_flags,	// acceptable types (type check flags)
 	int	offset,
 	int	arg_idx,
 	cctx_T	*cctx,
@@ -595,7 +599,7 @@ need_type(
 	where.wt_index = arg_idx;
 	where.wt_kind = WT_ARGUMENT;
     }
-    return need_type_where(actual, expected, number_ok, offset, where,
+    return need_type_where(actual, expected, typechk_flags, offset, where,
 						cctx, silent, actual_is_const);
 }
 
@@ -2521,7 +2525,7 @@ compile_load_lhs(
 	if (rhs_type != NULL && member_type != NULL
 		&& vartype != VAR_OBJECT && vartype != VAR_CLASS
 		&& rhs_type != &t_void
-		&& need_type(rhs_type, member_type, FALSE,
+		&& need_type(rhs_type, member_type, 0,
 					    -3, 0, cctx, FALSE, FALSE) == FAIL)
 	    return FAIL;
 
@@ -2680,13 +2684,13 @@ compile_assign_unlet(
 	    if (range)
 	    {
 		type = get_type_on_stack(cctx, 1);
-		if (need_type(type, &t_number, FALSE,
+		if (need_type(type, &t_number, 0,
 					    -2, 0, cctx, FALSE, FALSE) == FAIL)
 		return FAIL;
 	    }
 	    type = get_type_on_stack(cctx, 0);
 	    if ((dest_type != VAR_BLOB && type->tt_type != VAR_SPECIAL)
-		    && need_type(type, &t_number, FALSE,
+		    && need_type(type, &t_number, 0,
 					    -1, 0, cctx, FALSE, FALSE) == FAIL)
 		return FAIL;
 	}
@@ -3041,7 +3045,7 @@ compile_assign_list_check_rhs_type(cctx_T *cctx, cac_T *cac)
 
     if (need_type(stacktype,
 		  stacktype->tt_type == VAR_TUPLE ? &t_tuple_any : &t_list_any,
-		  FALSE, -1, 0, cctx, FALSE, FALSE) == FAIL)
+		  TYPECHK_TUPLE_OK, -1, 0, cctx, FALSE, FALSE) == FAIL)
 	return FAIL;
 
     if (stacktype->tt_type == VAR_TUPLE)
@@ -3280,7 +3284,7 @@ compile_assign_valid_rhs_type(
 	    !has_list_index(cac->cac_var_start + lhs->lhs_varlen, cctx))
 	use_type = lhs->lhs_member_type;
 
-    if (need_type_where(rhs_type, use_type, FALSE, -1, where, cctx, FALSE,
+    if (need_type_where(rhs_type, use_type, 0, -1, where, cctx, FALSE,
 						cac->cac_is_const) == FAIL)
 	return FALSE;
 
@@ -3342,7 +3346,7 @@ compile_assign_check_type(cctx_T *cctx, cac_T *cac)
 
 	if (*cac->cac_nextc != '=')
 	{
-	    if (need_type(rhs_type, lhs_type, FALSE, -1, 0, cctx, FALSE,
+	    if (need_type(rhs_type, lhs_type, 0, -1, 0, cctx, FALSE,
 							FALSE) == FAIL)
 		return FAIL;
 	}
@@ -3493,7 +3497,7 @@ compile_assign_compound_op(cctx_T *cctx, cac_T *cac)
 	expected = lhs->lhs_member_type;
 	stacktype = get_type_on_stack(cctx, 0);
 	if (expected != &t_string
-		&& need_type(stacktype, expected, FALSE, -1, 0, cctx,
+		&& need_type(stacktype, expected, 0, -1, 0, cctx,
 					FALSE, FALSE) == FAIL)
 	    return FAIL;
 	else if (may_generate_2STRING(-1, TOSTRING_NONE, cctx) == FAIL)
@@ -3511,8 +3515,8 @@ compile_assign_compound_op(cctx_T *cctx, cac_T *cac)
 		// If variable is float operation with number is OK.
 		!(expected == &t_float && (stacktype == &t_number
 					|| stacktype == &t_number_bool))
-		&& need_type(stacktype, expected, TRUE, -1, 0, cctx,
-					FALSE, FALSE) == FAIL)
+		&& need_type(stacktype, expected, TYPECHK_NUMBER_OK, -1, 0,
+						cctx, FALSE, FALSE) == FAIL)
 	    return FAIL;
     }
 
@@ -3659,7 +3663,7 @@ compile_assign_process_variables(
 	    SOURCING_LNUM = cac->cac_start_lnum;
 	    if (cac->cac_lhs.lhs_has_type
 		    && need_type(&t_list_string, cac->cac_lhs.lhs_type,
-			FALSE, -1, 0, cctx, FALSE, FALSE) == FAIL)
+				0, -1, 0, cctx, FALSE, FALSE) == FAIL)
 		return FAIL;
 	}
 	else
@@ -4119,7 +4123,7 @@ obj_constructor_prologue(ufunc_T *ufunc, cctx_T *cctx)
 		where_T	where = WHERE_INIT;
 		where.wt_kind = WT_MEMBER;
 		where.wt_func_name = (char *)m->ocm_name.string;
-		if (need_type_where(type, m->ocm_type, FALSE, -1,
+		if (need_type_where(type, m->ocm_type, 0, -1,
 					where, cctx, FALSE, FALSE) == FAIL)
 		    return FAIL;
 	    }
@@ -4224,7 +4228,7 @@ compile_def_function_default_args(
 	    ufunc->uf_arg_types[arg_idx] = val_type;
 	}
 	else if (need_type_where(val_type, ufunc->uf_arg_types[arg_idx],
-		    FALSE, -1, where, cctx, FALSE, FALSE) == FAIL)
+		    0, -1, where, cctx, FALSE, FALSE) == FAIL)
 	    return FAIL;
 
 	if (generate_STORE(cctx, ISN_STORE, i - count - off, NULL) == FAIL)
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 2fc6da8d75..25e56005bc 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -7871,6 +7871,9 @@ list_instructions(char *pfx, isn_T *instr, int instr_count, ufunc_T *ufunc)
 		      if (ct->ct_type->tt_type == VAR_FLOAT
 			      && (ct->ct_type->tt_flags & TTFLAG_NUMBER_OK))
 			  typename = "float|number";
+		      else if (ct->ct_type->tt_type == VAR_LIST
+			      && (ct->ct_type->tt_flags & TTFLAG_TUPLE_OK))
+			  typename = "list<any>|tuple<any>";
 		      else
 			  typename = type_name(ct->ct_type, &tofree);
 
diff --git a/src/vim9expr.c b/src/vim9expr.c
index a3714e592b..c8353ab981 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -162,13 +162,13 @@ compile_member(int is_slice, int *keeping_dict, cctx_T *cctx)
     if (vartype == VAR_STRING || vartype == VAR_LIST || vartype == VAR_BLOB
 						|| vartype == VAR_TUPLE)
     {
-	if (need_type(idxtype, &t_number, FALSE,
+	if (need_type(idxtype, &t_number, 0,
 					    -1, 0, cctx, FALSE, FALSE) == FAIL)
 	    return FAIL;
 	if (is_slice)
 	{
 	    idxtype = get_type_on_stack(cctx, 1);
-	    if (need_type(idxtype, &t_number, FALSE,
+	    if (need_type(idxtype, &t_number, 0,
 					    -2, 0, cctx, FALSE, FALSE) == FAIL)
 		return FAIL;
 	}
@@ -199,7 +199,7 @@ compile_member(int is_slice, int *keeping_dict, cctx_T *cctx)
 	}
 	else
 	{
-	    if (need_type(typep->type_curr, &t_dict_any, FALSE,
+	    if (need_type(typep->type_curr, &t_dict_any, 0,
 					    -2, 0, cctx, FALSE, FALSE) == FAIL)
 		return FAIL;
 	    typep->type_curr = &t_any;
@@ -2374,7 +2374,7 @@ bool_on_stack(cctx_T *cctx)
 	// This requires a runtime type check.
 	return generate_COND2BOOL(cctx);
 
-    return need_type(type, &t_bool, FALSE, -1, 0, cctx, FALSE, FALSE);
+    return need_type(type, &t_bool, 0, -1, 0, cctx, FALSE, FALSE);
 }
 
 /*
@@ -2408,7 +2408,7 @@ compile_leader(cctx_T *cctx, int numeric_only, char_u *start, char_u **end)
 	{
 	    type_T *type = get_type_on_stack(cctx, 0);
 	    if (type->tt_type != VAR_FLOAT && need_type(type, &t_number,
-				     FALSE, -1, 0, cctx, FALSE, FALSE) == FAIL)
+				     0, -1, 0, cctx, FALSE, FALSE) == FAIL)
 		return FAIL;
 
 	    // only '-' has an effect, for '+' we only check the type
@@ -3196,8 +3196,8 @@ compile_expr8(char_u **arg, cctx_T *cctx, ppconst_T *ppconst)
 	actual = get_type_on_stack(cctx, 0);
 	if (check_type_maybe(want_type, actual, FALSE, where) != OK)
 	{
-	    if (need_type_where(actual, want_type, FALSE, -1, where, cctx, FALSE, FALSE)
-		    == FAIL)
+	    if (need_type_where(actual, want_type, 0, -1, where, cctx, FALSE,
+							FALSE) == FAIL)
 		return FAIL;
 	}
     }
@@ -3438,7 +3438,7 @@ compile_expr5(char_u **arg, cctx_T *cctx, ppconst_T *ppconst)
 	{
 	    type_T	*t = get_type_on_stack(cctx, 0);
 
-	    if (need_type(t, &t_number, FALSE, 0, 0, cctx, FALSE, FALSE) == FAIL)
+	    if (need_type(t, &t_number, 0, 0, 0, cctx, FALSE, FALSE) == FAIL)
 	    {
 		emsg(_(e_bitshift_ops_must_be_number));
 		return FAIL;
@@ -3493,7 +3493,7 @@ compile_expr5(char_u **arg, cctx_T *cctx, ppconst_T *ppconst)
 	}
 	else
 	{
-	    if (need_type(get_type_on_stack(cctx, 0), &t_number, FALSE,
+	    if (need_type(get_type_on_stack(cctx, 0), &t_number, 0,
 					     0, 0, cctx, FALSE, FALSE) == FAIL)
 	    {
 		emsg(_(e_bitshift_ops_must_be_number));
diff --git a/src/vim9instr.c b/src/vim9instr.c
index 26eedaa235..c11e913b0a 100644
--- a/src/vim9instr.c
+++ b/src/vim9instr.c
@@ -694,7 +694,7 @@ generate_COND2BOOL(cctx_T *cctx)
 generate_TYPECHECK(
 	cctx_T	    *cctx,
 	type_T	    *expected,
-	int	    number_ok,	    // add TTFLAG_NUMBER_OK flag
+	int	    typechk_flags,	// type check flags
 	int	    offset,
 	int	    is_var,
 	int	    argidx)
@@ -705,7 +705,10 @@ generate_TYPECHECK(
     if ((isn = generate_instr(cctx, ISN_CHECKTYPE)) == NULL)
 	return FAIL;
     type_T *tt;
-    if (expected->tt_type == VAR_FLOAT && number_ok)
+    if ((expected->tt_type == VAR_FLOAT
+		&& (typechk_flags & TYPECHK_NUMBER_OK))
+	    || (expected->tt_type == VAR_LIST
+		&& (typechk_flags & TYPECHK_TUPLE_OK)))
     {
 	// always allocate, also for static types
 	tt = ALLOC_ONE(type_T);
@@ -713,7 +716,10 @@ generate_TYPECHECK(
 	{
 	    *tt = *expected;
 	    tt->tt_flags &= ~TTFLAG_STATIC;
-	    tt->tt_flags |= TTFLAG_NUMBER_OK;
+	    if (typechk_flags & TYPECHK_NUMBER_OK)
+		tt->tt_flags |= TTFLAG_NUMBER_OK;
+	    else
+		tt->tt_flags |= TTFLAG_TUPLE_OK;
 	}
     }
     else
@@ -1846,7 +1852,7 @@ generate_BCALL(cctx_T *cctx, int func_idx, int argcount, int method_call)
     if (maptype != NULL && maptype[0].type_decl->tt_member != NULL
 				  && maptype[0].type_decl->tt_member != &t_any)
 	// Check that map() didn't change the item types.
-	generate_TYPECHECK(cctx, maptype[0].type_decl, FALSE, -1, FALSE, 1);
+	generate_TYPECHECK(cctx, maptype[0].type_decl, 0, -1, FALSE, 1);
 
     return OK;
 }
@@ -1870,7 +1876,7 @@ generate_LISTAPPEND(cctx_T *cctx)
 	return FAIL;
     item_type = get_type_on_stack(cctx, 0);
     expected = list_type->tt_member;
-    if (need_type(item_type, expected, FALSE, -1, 0, cctx, FALSE, FALSE) == FAIL)
+    if (need_type(item_type, expected, 0, -1, 0, cctx, FALSE, FALSE) == FAIL)
 	return FAIL;
 
     if (generate_instr(cctx, ISN_LISTAPPEND) == NULL)
@@ -1893,8 +1899,7 @@ generate_BLOBAPPEND(cctx_T *cctx)
     if (arg_type_modifiable(get_decl_type_on_stack(cctx, 1), 1) == FAIL)
 	return FAIL;
     item_type = get_type_on_stack(cctx, 0);
-    if (need_type(item_type, &t_number, FALSE,
-					    -1, 0, cctx, FALSE, FALSE) == FAIL)
+    if (need_type(item_type, &t_number, 0, -1, 0, cctx, FALSE, FALSE) == FAIL)
 	return FAIL;
 
     if (generate_instr(cctx, ISN_BLOBAPPEND) == NULL)
@@ -1971,7 +1976,7 @@ generate_CALL(
 		expected = &t_any;
 	    else
 		expected = ufunc->uf_va_type->tt_member;
-	    if (need_type(actual, expected, FALSE,
+	    if (need_type(actual, expected, 0,
 			      -argcount + i, i + 1, cctx, TRUE, FALSE) == FAIL)
 	    {
 		arg_type_mismatch(expected, actual, i + 1);
@@ -2108,7 +2113,7 @@ check_func_args_from_type(
 		    expected = &t_any;
 		else
 		    expected = type->tt_args[i];
-		if (need_type(actual, expected, FALSE,
+		if (need_type(actual, expected, 0,
 				     offset, i + 1, cctx, TRUE, FALSE) == FAIL)
 		{
 		    arg_type_mismatch(expected, actual, i + 1);
diff --git a/src/vim9type.c b/src/vim9type.c
index 393b852514..938eee00c5 100644
--- a/src/vim9type.c
+++ b/src/vim9type.c
@@ -1372,6 +1372,11 @@ check_type_maybe(
 			     || (actual->tt_flags & TTFLAG_FLOAT_OK)))
 		// Using a number where a float is expected is OK here.
 		return OK;
+	    if (expected->tt_type == VAR_LIST
+		    && actual->tt_type == VAR_TUPLE
+		    && (expected->tt_flags & TTFLAG_TUPLE_OK))
+		// Using a tuple where a list is expected is OK here.
+		return OK;
 	    if (give_msg)
 		type_mismatch_where(expected, actual, where);
 	    return FAIL;