[PATCH] kconfig: nconf: Fix uncleared lines on help screens

From: Shankari Anand
Date: Sat Jul 19 2025 - 10:32:29 EST


commit 1b92b18ec419 ("kconfig: nconf: Ensure null termination where
strncpy is used")
introduced a regression where help screens (F1, F2, F3) no longer properly
clear short lines of text,
resulting in duplicated or trailing content when lines are overwritten.

Revert the null-termination change to match
the actual length of the copied string.

Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Fixes: 1b92b18ec419 ("kconfig: nconf: Ensure null termination where strncpy is used")
Signed-off-by: Shankari Anand <shankari.ak0208@xxxxxxxxx>
---
I apologise for the overlook from my side. This should set it right.
Link of the report :
https://lore.kernel.org/lkml/CAK7LNAT54nvwYmTy20Ep8U2kr4thn68yYWXi9R-d3Yx3iXs=Bg@xxxxxxxxxxxxxx/T/#
---
scripts/kconfig/nconf.gui.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/kconfig/nconf.gui.c b/scripts/kconfig/nconf.gui.c
index 475a403ab8ba..7206437e784a 100644
--- a/scripts/kconfig/nconf.gui.c
+++ b/scripts/kconfig/nconf.gui.c
@@ -177,7 +177,7 @@ void fill_window(WINDOW *win, const char *text)
const char *line = get_line(text, i);
int len = get_line_length(line);
strncpy(tmp, line, min(len, x));
- tmp[sizeof(tmp) - 1] = '\0';
+ tmp[len] = '\0';
mvwprintw(win, i, 0, "%s", tmp);
}
}

base-commit: d086c886ceb9f59dea6c3a9dae7eb89e780a20c9
--
2.34.1