From 740e193f599ffcaa0e95926dd805e9a201d9ba78 Mon Sep 17 00:00:00 2001
From: Val Lorentz <progval+git@progval.net>
Date: Sat, 19 Mar 2022 19:13:10 +0100
Subject: [PATCH] Add support for the <count> param of WHOWAS (#1968)

Not very useful IMO, but every server but InspIRCd seems to implement it,
and it's part of the RFCs:

* https://datatracker.ietf.org/doc/html/rfc1459#section-4.5.3
* https://datatracker.ietf.org/doc/html/rfc2812#section-3.6.3
---
 docs/conf/helpop.conf.example |  4 +++-
 src/coremods/core_whowas.cpp  | 12 ++++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/docs/conf/helpop.conf.example b/docs/conf/helpop.conf.example
index e05da8cff..a61a02753 100644
--- a/docs/conf/helpop.conf.example
+++ b/docs/conf/helpop.conf.example
@@ -419,9 +419,11 @@ server.
 You should not use it during an established connection.
 ">
 
-<helpop key="whowas" title="/WHOWAS <nick>" value="
+<helpop key="whowas" title="/WHOWAS <nick> [<count>]" value="
 Returns a list of times the user was seen recently on IRC along with
 the time they were last seen and their server.
+
+If <count> is given, only return the <count> most recent entries.
 ">
 
 <helpop key="links" title="/LINKS" value="
diff --git a/src/coremods/core_whowas.cpp b/src/coremods/core_whowas.cpp
index 893cd83be..d80a3a3d2 100644
--- a/src/coremods/core_whowas.cpp
+++ b/src/coremods/core_whowas.cpp
@@ -187,7 +187,7 @@ class CommandWhowas : public Command
 CommandWhowas::CommandWhowas( Module* parent)
 	: Command(parent, "WHOWAS", 1)
 {
-	syntax = "<nick>";
+	syntax = "<nick> [<count>]";
 	Penalty = 2;
 }
 
@@ -208,7 +208,15 @@ CmdResult CommandWhowas::Handle(User* user, const Params& parameters)
 	else
 	{
 		const WhoWas::Nick::List& list = nick->entries;
-		for (WhoWas::Nick::List::const_reverse_iterator i = list.rbegin(); i != list.rend(); ++i)
+		WhoWas::Nick::List::const_reverse_iterator last = list.rend();
+		if (parameters.size() > 1)
+		{
+			size_t count = ConvToNum<size_t>(parameters[1]);
+			if (count > 0 && (size_t) std::distance(list.rbegin(), last) > count)
+				last = list.rbegin() + count;
+		}
+
+		for (WhoWas::Nick::List::const_reverse_iterator i = list.rbegin(); i != last; ++i)
 		{
 			WhoWas::Entry* u = *i;