invoice: change default expiry to 7 days.

For online services, shorter may be fine, but for casual use I'm usually
in a different timezone than the payer, so needs to be at least 1 day.

Certainly 1 hr is short if they have to open a channel.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

CHANGELOG.md

@@ -15,6 +15,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- JSON API: `invoice` expiry defaults to 7 days.
+
 ### Deprecated
 
 Note: You should always set `allow-deprecated-apis=false` to test for

doc/lightning-invoice.7

@@ -2,12 +2,12 @@
 .\"     Title: lightning-invoice
 .\"    Author: [see the "AUTHOR" section]
 .\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
-.\"      Date: 02/23/2019
+.\"      Date: 04/10/2019
 .\"    Manual: \ \&
 .\"    Source: \ \&
 .\"  Language: English
 .\"
-.TH "LIGHTNING\-INVOICE" "7" "02/23/2019" "\ \&" "\ \&"
+.TH "LIGHTNING\-INVOICE" "7" "04/10/2019" "\ \&" "\ \&"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -42,7 +42,7 @@ The \fIlabel\fR must be a unique string or number (which is treated as a string,
 .sp
 The \fIdescription\fR is a short description of purpose of payment, e\&.g\&. \fI1 cup of coffee\fR\&. This value is encoded into the BOLT11 invoice and is viewable by any node you send this invoice to\&. It must be UTF\-8, and cannot use \fI\eu\fR JSON escape codes\&.
 .sp
-The \fIexpiry\fR is optionally the number of seconds the invoice is valid for\&. If no value is provided the default of 3600 (1 Hour) is used\&.
+The \fIexpiry\fR is optionally the number of seconds the invoice is valid for\&. If no value is provided the default of 604800 (1 week) is used\&.
 .sp
 The \fIfallbacks\fR array is one or more fallback addresses to include in the invoice (in order from most\-preferred to least): note that these arrays are not currently tracked to fulfill the invoice\&.
 .sp

doc/lightning-invoice.7.txt

@@ -35,7 +35,7 @@ and is viewable by any node you send this invoice to.  It must be
 UTF-8, and cannot use '\u' JSON escape codes.
 
 The 'expiry' is optionally the number of seconds the invoice is valid for.
-If no value is provided the default of 3600 (1 Hour) is used.
+If no value is provided the default of 604800 (1 week) is used.
 
 The 'fallbacks' array is one or more fallback addresses to include in
 the invoice (in order from most-preferred to least): note that these

lightningd/invoice.c

@@ -415,7 +415,7 @@ static struct command_result *json_invoice(struct command *cmd,
 		   p_req("msatoshi", param_msat_or_any, &msatoshi_val),
 		   p_req("label", param_label, &info->label),
 		   p_req("description", param_escaped_string, &desc_val),
-		   p_opt_def("expiry", param_u64, &expiry, 3600),
+		   p_opt_def("expiry", param_u64, &expiry, 3600*24*7),
 		   p_opt("fallbacks", param_array, &fallbacks),
 		   p_opt("preimage", param_tok, &preimagetok),
 		   p_opt("exposeprivatechannels", param_bool, &exposeprivate),