mwan3: fix empty rpcd integer state in 2.12.3

An empty mwan3track state file becomes NaN in the rpcd response. Default
failed integer conversions to zero, as the shell handler did.

Add a focused regression for the installed integer helpers in a separate
ucode file called from test.sh, and bump the package version.

Fixes: #29653
Signed-off-by: Yuen Su <zypulsecore@gmail.com>

net/mwan3/Makefile

@@ -8,8 +8,8 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=mwan3
-PKG_VERSION:=2.12.2
-PKG_RELEASE:=2
+PKG_VERSION:=2.12.3
+PKG_RELEASE:=1
 
 PKG_MAINTAINER:=Florian Eckert <fe@dev.tdt.de>
 PKG_LICENSE:=GPL-2.0

net/mwan3/files/usr/share/rpcd/ucode/mwan3

@@ -14,7 +14,7 @@ function get_str(iface, property) {
 }
 
 function get_int(iface, property) {
-	return int(get_str(iface, property));
+	return int(get_str(iface, property)) || 0;
 }
 
 function get_uptime() {

net/mwan3/test-rpcd.uc

@@ -0,0 +1,17 @@
+import { readfile } from 'fs';
+
+const source = readfile('/usr/share/rpcd/ucode/mwan3');
+const begin = index(source, 'function get_str_raw(');
+const end = index(source, 'function get_uptime(');
+if (begin < 0 || end <= begin)
+	die('Cannot find mwan3 integer helpers\n');
+const read_integer = loadstring(substr(source, begin, end - begin) +
+	'\nreturn get_int("wan", "SCORE");', { raw_mode: true });
+
+for (let sample in [['', 0], [null, 0], ['\n', 0], ['invalid', 0],
+	['0', 0], ['17', 17], ['17\n', 17]]) {
+	const actual = call(read_integer, null, { readfile: () => sample[0] });
+	if (actual !== sample[1])
+		die(sprintf('get_int(%J): expected %d, got %J\n', sample[0], sample[1], actual));
+	printf('get_int(%J): %d\n', sample[0], actual);
+}

net/mwan3/test.sh

@@ -37,3 +37,7 @@ actual=$(sanitize_route "$ipv6_route")
 	echo "actual:   '$actual'" >&2
 	exit 1
 }
+
+# Check that empty, missing and invalid rpcd state becomes zero.
+# Numeric values must be preserved.
+ucode -S "$(dirname "$0")/test-rpcd.uc"