patch 8.2.2942: Vim9: error when calling function with too few argumentsv8.2.2942

Problem:    Vim9: internal error when calling function with too few arguments
Solution:   Check for argument count to be too few. (closes #8325)

4 files changed, 23 insertions, 0 deletions

diff --git a/src/errors.h b/src/errors.h
index 00e2d565d..94a752ae6 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -419,3 +419,7 @@ EXTERN char e_cannot_open_terminal_from_command_line_window[]
 	INIT(= N_("E1188: Cannot open a terminal from the command line window"));
 EXTERN char e_cannot_use_legacy_with_command_str[]
 	INIT(= N_("E1189: Cannot use :legacy with this command: %s"));
+EXTERN char e_one_argument_too_few[]
+	INIT(= N_("E1190: One argument too few"));
+EXTERN char e_nr_arguments_too_few[]
+	INIT(= N_("E1190: %d arguments too few"));
diff --git a/src/testdir/test_vim9_builtin.vim b/src/testdir/test_vim9_builtin.vim
index 3fa5eb306..9cae4a34e 100644
--- a/src/testdir/test_vim9_builtin.vim
+++ b/src/testdir/test_vim9_builtin.vim
@@ -810,6 +810,15 @@ def Test_map_function_arg()
       assert_equal(['0:a', '1:b', '2:c'], l)
   END
   CheckDefAndScriptSuccess(lines)
+
+  lines =<< trim END
+      range(3)->map((a, b, c) => a + b + c)
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1190: One argument too few')
+  lines =<< trim END
+      range(3)->map((a, b, c, d) => a + b + c + d)
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1190: 2 arguments too few')
 enddef
 
 def Test_map_item_type()
diff --git a/src/version.c b/src/version.c
index 0f539ca2e..ce8273f48 100644
--- 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 */
 /**/
+    2942,
+/**/
     2941,
 /**/
     2940,
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 982667829..c2a7de50d 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -4234,6 +4234,14 @@ call_def_function(
 	    semsg(_(e_nr_arguments_too_many), idx);
 	goto failed_early;
     }
+    else if (idx < 0)
+    {
+	if (idx == -1)
+	    emsg(_(e_one_argument_too_few));
+	else
+	    semsg(_(e_nr_arguments_too_few), -idx);
+	goto failed_early;
+    }
 
     // Put arguments on the stack, but no more than what the function expects.
     // A lambda can be called with more arguments than it uses.