From 77c867d95fc673499de58413cefdf9cd28677c80 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Mon, 3 Feb 2020 10:59:42 +1030
Subject: [PATCH] common: fix bolt11 parsing of unknown `f` versions.

As tested in next test.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 common/bolt11.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/common/bolt11.c b/common/bolt11.c
index 81483ff9f..d0c84315c 100644
--- a/common/bolt11.c
+++ b/common/bolt11.c
@@ -390,9 +390,14 @@ static char *decode_f(struct bolt11 *b11,
                 fallback = scriptpubkey_witness_raw(b11, version,
 						    f, tal_count(f));
                 tal_free(f);
-        } else
+        } else {
+		/* Restore version for unknown field! */
+		(*data)--;
+		(*data_len)++;
+		data_length++;
                 return unknown_field(b11, hu5, data, data_len, 'f',
                                      data_length);
+	}
 
 	if (b11->fallbacks == NULL)
 		b11->fallbacks = tal_arr(b11, const u8 *, 1);