Commit: patch 9.1.1765: f_isnan() and f_isinf() do not correctly initialize rettv type

[Christian Brabandt]

patch 9.1.1765: f_isnan() and f_isinf() do not correctly initialize rettv type

Commit: https://github.com/vim/vim/commit/19fa46a469743653a16a48c4222482d9f33e30a2
Author: Damien Lejay <dam...@lejay.be>
Date: Mon Sep 15 19:55:25 2025 +0000

patch 9.1.1765: f_isnan() and f_isinf() do not correctly initialize rettv type

Problem: f_isnan() and f_isinf() do not correctly initialize rettv type
Solution: Initialize them with type: VAR_NUMBER and value 0 (Damien Lejay).

Both builtins wrote only rettv->vval.v_number and relied on call_func()
initialising rettv->v_type to VAR_NUMBER. Explicitly set

rettv->v_type = VAR_NUMBER;
rettv->vval.v_number = 0;

at function entry to avoid undefined behaviour and make the return type
self-contained.

closes: #18307

Signed-off-by: Damien Lejay <dam...@lejay.be>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/src/float.c b/src/float.c
index 4c8e5fe10..fcdaaefa9 100644
--- a/src/float.c
+++ b/src/float.c
@@ -345,6 +345,9 @@ f_fmod(typval_T *argvars, typval_T *rettv)
void
f_isinf(typval_T *argvars, typval_T *rettv)
{
+ rettv->v_type = VAR_NUMBER;
+ rettv->vval.v_number = 0;
+
if (in_vim9script() && check_for_float_or_nr_arg(argvars, 0) == FAIL)
return;

@@ -358,6 +361,9 @@ f_isinf(typval_T *argvars, typval_T *rettv)
void
f_isnan(typval_T *argvars, typval_T *rettv)
{
+ rettv->v_type = VAR_NUMBER;
+ rettv->vval.v_number = 0;
+
if (in_vim9script() && check_for_float_or_nr_arg(argvars, 0) == FAIL)
return;

diff --git a/src/version.c b/src/version.c
index 1e231bf31..f58befda0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -724,6 +724,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 1765,
/**/
1764,
/**/