net.unbound: Merge luaunbound and prosody defaults in absence of user config (fixes #1763) (thanks rgd)

add_defaults() is supposed to merge 3 tables, the defaults in
luaunbound, the defaults from prosody and any config from the prosody
config file.  In the case where no `unbound={}` has been in the config,
it skips over the merge and returns only the prosody built-in defaults.

This results in libunbound skipping reading resolv.conf and uses its
default behavior of full recursive resolution.

Prior to #1737 there were only two tables, the luaunbound defaults and
the prosody config, where bypassing the merge and returning the former
did the right thing.

1 files changed, 8 insertions, 11 deletions

diff --git a/net/unbound.lua b/net/unbound.lua
index 4d8f9284..ee742b7c 100644
--- a/net/unbound.lua
+++ b/net/unbound.lua
@@ -28,19 +28,16 @@ local parsers = dns_utils.parsers;
 local builtin_defaults = { hoststxt = false }
 
 local function add_defaults(conf)
-	if conf then
-		for option, default in pairs(builtin_defaults) do
-			if conf[option] == nil then
-				conf[option] = default;
-			end
+	conf = conf or {};
+	for option, default in pairs(builtin_defaults) do
+		if conf[option] == nil then
+			conf[option] = default;
 		end
-		for option, default in pairs(libunbound.config) do
-			if conf[option] == nil then
-				conf[option] = default;
-			end
+	end
+	for option, default in pairs(libunbound.config) do
+		if conf[option] == nil then
+			conf[option] = default;
 		end
-	else
-		return builtin_defaults;
 	end
 	return conf;
 end