decode: fix handling of blinded_payinfo.

Our pay code handles this correctly, but decode was still using an old model
where there was a payinfo per hop, not per path.

Reported-by: @t-bast
See: #5823
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

doc/lightning-decode.7.md

@@ -148,13 +148,14 @@ If **type** is "bolt12 invoice", and **valid** is *true*:
   - **invoice\_paths** (array of objects): Paths to pay the destination:
     - **first\_node\_id** (pubkey): the (presumably well-known) public key of the start of the path
     - **blinding** (pubkey): blinding factor for this path
+    - **payinfo** (object):
+      - **fee\_base\_msat** (msat): basefee for path
+      - **fee\_proportional\_millionths** (u32): proportional fee for path
+      - **cltv\_expiry\_delta** (u32): CLTV delta for path
+      - **features** (hex): features allowed for path
     - **path** (array of objects): an individual path:
       - **blinded\_node\_id** (pubkey): node\_id of the hop
       - **encrypted\_recipient\_data** (hex): encrypted TLV entry for this hop
-      - **fee\_base\_msat** (msat, optional): basefee for path
-      - **fee\_proportional\_millionths** (u32, optional): proportional fee for path
-      - **cltv\_expiry\_delta** (u32, optional): CLTV delta for path
-      - **features** (hex, optional): features allowed for path
   - **invoice\_created\_at** (u64): the UNIX timestamp of invoice creation
   - **invoice\_payment\_hash** (hex): the hash of the *payment\_preimage* (always 64 characters)
   - **invoice\_amount\_msat** (msat): the amount required to fulfill invoice
@@ -302,4 +303,4 @@ RESOURCES
 
 Main web site: <https://github.com/ElementsProject/lightning>
 
-[comment]: # ( SHA256STAMP:eadd9b06e6cb495a794568f3a9e2371c09718311c0b61ad05b0fca3014c429d3)
+[comment]: # ( SHA256STAMP:a8843027b18a1d54efcf0ca423fc6fbe0c2136d32fa3d8c552a875b6844dd950)

doc/schemas/decode.schema.json

@@ -927,6 +927,7 @@
               "required": [
                 "first_node_id",
                 "blinding",
+                "payinfo",
                 "path"
               ],
               "additionalProperties": false,
@@ -939,6 +940,34 @@
                   "type": "pubkey",
                   "description": "blinding factor for this path"
                 },
+                "payinfo": {
+                  "type": "object",
+                  "required": [
+                    "fee_base_msat",
+                    "fee_proportional_millionths",
+                    "cltv_expiry_delta",
+                    "features"
+                  ],
+                  "additionalProperties": false,
+                  "properties": {
+                    "fee_base_msat": {
+                      "type": "msat",
+                      "description": "basefee for path"
+                    },
+                    "fee_proportional_millionths": {
+                      "type": "u32",
+                      "description": "proportional fee for path"
+                    },
+                    "cltv_expiry_delta": {
+                      "type": "u32",
+                      "description": "CLTV delta for path"
+                    },
+                    "features": {
+                      "type": "hex",
+                      "description": "features allowed for path"
+                    }
+                  }
+                },
                 "path": {
                   "type": "array",
                   "description": "an individual path",
@@ -957,22 +986,6 @@
                       "encrypted_recipient_data": {
                         "type": "hex",
                         "description": "encrypted TLV entry for this hop"
-                      },
-                      "fee_base_msat": {
-                        "type": "msat",
-                        "description": "basefee for path"
-                      },
-                      "fee_proportional_millionths": {
-                        "type": "u32",
-                        "description": "proportional fee for path"
-                      },
-                      "cltv_expiry_delta": {
-                        "type": "u32",
-                        "description": "CLTV delta for path"
-                      },
-                      "features": {
-                        "type": "hex",
-                        "description": "features allowed for path"
                       }
                     }
                   }