From 38d229df3d5c1822159fd41d1b2191cd8257e26c Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Sun, 17 Nov 2024 16:09:06 +1030
Subject: [PATCH] tools/generate-wire.py: make sure TLV array fields are
 allocated off TLV.

Otherwise the whole thing cannot be tal_steal() onto a different parent.

Here's the difference in generated files:

   --- ./wire/onion_wiregen.c.pre	2024-10-23 12:26:09.023176933 +1030
   +++ ./wire/onion_wiregen.c	2024-10-23 12:26:52.434828303 +1030
   @@ -128,7 +128,7 @@
     	blinded_path->path = num_hops ? tal_arr(blinded_path, struct blinded_path_hop *, 0) : NULL;
    	for (size_t i = 0; i < num_hops; i++) {
    		struct blinded_path_hop * tmp;
   -		tmp = fromwire_blinded_path_hop(blinded_path, cursor, plen);
   +		tmp = fromwire_blinded_path_hop(blinded_path->path, cursor, plen);
    		tal_arr_expand(&blinded_path->path, tmp);
    	}

   --- ./wire/bolt12_wiregen.c.pre	2024-10-23 12:26:09.079176474 +1030
   +++ ./wire/bolt12_wiregen.c	2024-10-23 12:26:52.612826902 +1030
   @@ -316,7 +316,7 @@
    	r->offer_paths = *plen ? tal_arr(r, struct blinded_path *, 0) : NULL;
    	while (*plen != 0) {
    		struct blinded_path * tmp;
   -		tmp = fromwire_blinded_path(r, cursor, plen);
   +		tmp = fromwire_blinded_path(r->offer_paths, cursor, plen);
    		tal_arr_expand(&r->offer_paths, tmp);
    	}
    }
   @@ -729,7 +729,7 @@
    	r->offer_paths = *plen ? tal_arr(r, struct blinded_path *, 0) : NULL;
    	while (*plen != 0) {
    		struct blinded_path * tmp;
   -		tmp = fromwire_blinded_path(r, cursor, plen);
   +		tmp = fromwire_blinded_path(r->offer_paths, cursor, plen);
    		tal_arr_expand(&r->offer_paths, tmp);
    	}
    }
   @@ -1052,7 +1052,7 @@
    	r->invreq_paths = *plen ? tal_arr(r, struct blinded_path *, 0) : NULL;
    	while (*plen != 0) {
    		struct blinded_path * tmp;
   -		tmp = fromwire_blinded_path(r, cursor, plen);
   +		tmp = fromwire_blinded_path(r->invreq_paths, cursor, plen);
    		tal_arr_expand(&r->invreq_paths, tmp);
    	}
    }
   @@ -1385,7 +1385,7 @@
    	r->offer_paths = *plen ? tal_arr(r, struct blinded_path *, 0) : NULL;
    	while (*plen != 0) {
    		struct blinded_path * tmp;
   -		tmp = fromwire_blinded_path(r, cursor, plen);
   +		tmp = fromwire_blinded_path(r->offer_paths, cursor, plen);
    		tal_arr_expand(&r->offer_paths, tmp);
    	}
    }
   @@ -1708,7 +1708,7 @@
    	r->invreq_paths = *plen ? tal_arr(r, struct blinded_path *, 0) : NULL;
    	while (*plen != 0) {
    		struct blinded_path * tmp;
   -		tmp = fromwire_blinded_path(r, cursor, plen);
   +		tmp = fromwire_blinded_path(r->invreq_paths, cursor, plen);
    		tal_arr_expand(&r->invreq_paths, tmp);
    	}
    }
   @@ -1781,7 +1781,7 @@
    	r->invoice_paths = *plen ? tal_arr(r, struct blinded_path *, 0) : NULL;
    	while (*plen != 0) {
    		struct blinded_path * tmp;
   -		tmp = fromwire_blinded_path(r, cursor, plen);
   +		tmp = fromwire_blinded_path(r->invoice_paths, cursor, plen);
    		tal_arr_expand(&r->invoice_paths, tmp);
    	}
    }
   @@ -1808,7 +1808,7 @@
    	r->invoice_blindedpay = *plen ? tal_arr(r, struct blinded_payinfo *, 0) : NULL;
    	while (*plen != 0) {
    		struct blinded_payinfo * tmp;
   -		tmp = fromwire_blinded_payinfo(r, cursor, plen);
   +		tmp = fromwire_blinded_payinfo(r->invoice_blindedpay, cursor, plen);
    		tal_arr_expand(&r->invoice_blindedpay, tmp);
    	}
    }
   @@ -1927,7 +1927,7 @@
    	r->invoice_fallbacks = *plen ? tal_arr(r, struct fallback_address *, 0) : NULL;
    	while (*plen != 0) {
    		struct fallback_address * tmp;
   -		tmp = fromwire_fallback_address(r, cursor, plen);
   +		tmp = fromwire_fallback_address(r->invoice_fallbacks, cursor, plen);
    		tal_arr_expand(&r->invoice_fallbacks, tmp);
    	}
    }

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 tools/gen/impl_template | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/gen/impl_template b/tools/gen/impl_template
index ec6f9d196..a6a166694 100644
--- a/tools/gen/impl_template
+++ b/tools/gen/impl_template
@@ -98,7 +98,7 @@ ${fieldname} = ${f.size('*plen')} ? tal_arr(${ctx}, ${typename}, 0) : NULL;
 	% if f.type_obj.is_assignable():
 		tmp = fromwire_${type_}(cursor, plen);
 	% elif f.is_varlen() and f.type_obj.is_varsize():
-		tmp = fromwire_${type_}(${ctx}, cursor, plen);
+		tmp = fromwire_${type_}(${fieldname}, cursor, plen);
 	% else:
 		fromwire_${type_}(cursor, plen, &tmp);
 	% endif