From 310e8e04a05d9eb43fa9dd7f00143300afcaa37a Mon Sep 17 00:00:00 2001
From: David Bauer <mail@david-bauer.net>
Date: Fri, 11 Nov 2022 13:33:44 +0100
Subject: [PATCH] kconfig: abort configuration on unset symbol

When a target configuration has unset Kconfig symbols, the build will
fail when OpenWrt is compiled with V=s and stdin is connected to a tty.

In case OpenWrt is compiled without either of these preconditions, the
build will succeed with the symbols in question being unset.

Modify the kernel configuration in a way it fails on unset symbols
regardless of the aforementioned preconditions.

Signed-off-by: David Bauer <mail@david-bauer.net>
---
 scripts/kconfig/conf.c | 6 ++++++
 1 file changed, 6 insertions(+)

--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -338,6 +338,9 @@ static int conf_askvalue(struct symbol *
 		}
 		/* fall through */
 	default:
+		if (!tty_stdio && getenv("FAIL_ON_UNCONFIGURED")) {
+			exit(1);
+		}
 		fflush(stdout);
 		xfgets(line, sizeof(line), stdin);
 		break;
@@ -520,6 +523,9 @@ static int conf_choice(struct menu *menu
 			}
 			/* fall through */
 		case oldaskconfig:
+			if (!tty_stdio && getenv("FAIL_ON_UNCONFIGURED")) {
+				exit(1);
+			}
 			fflush(stdout);
 			xfgets(line, sizeof(line), stdin);
 			strip(line);
