fix(router) wildcard host matching not considered with plain host match

kong/router.lua

@@ -512,7 +512,8 @@ end
 do
   local matchers = {
     [MATCH_RULES.HOST] = function(route_t, ctx)
-      local host = route_t.hosts[ctx.hits.host or ctx.req_host]
+      local host = route_t.hosts[ctx.req_host] or
+                   route_t.hosts[ctx.hits.host]
       if host then
         ctx.matches.host = host
 
@@ -705,7 +706,8 @@ end
 do
   local reducers = {
     [MATCH_RULES.HOST] = function(category, ctx)
-      return category.routes_by_hosts[ctx.hits.host]
+      return category.routes_by_hosts[ctx.req_host] or
+             category.routes_by_hosts[ctx.hits.host]
     end,
 
     [MATCH_RULES.URI] = function(category, ctx)
@@ -986,23 +988,24 @@ function _M.new(routes)
 
     -- host match
 
-    if plain_indexes.hosts[ctx.req_host] then
-      req_category = bor(req_category, MATCH_RULES.HOST)
-
-    elseif ctx.req_host then
+    do
+      local wildcard_match, _, err
       for i = 1, #wildcard_hosts do
-        local from, _, err = re_find(ctx.req_host, wildcard_hosts[i].regex, "ajo")
+        wildcard_match, _, err = re_find(ctx.req_host, wildcard_hosts[i].regex, "ajo")
         if err then
           log(ERR, "could not match wildcard host: ", err)
           return
         end
 
-        if from then
-          hits.host    = wildcard_hosts[i].value
-          req_category = bor(req_category, MATCH_RULES.HOST)
+        if wildcard_match then
+          hits.host = wildcard_hosts[i].value
           break
         end
       end
+
+      if wildcard_match or plain_indexes.hosts[ctx.req_host] then
+        req_category = bor(req_category, MATCH_RULES.HOST)
+      end
     end
 
     -- uri match

spec/02-integration/05-proxy/02-router_spec.lua

@@ -882,6 +882,63 @@ for _, strategy in helpers.each_strategy() do
       end)
     end)
 
+    describe("[paths] + [hosts] (plain and wildcard)", function()
+      local routes
+
+      lazy_setup(function()
+        routes = insert_routes {
+          {
+            strip_path = true,
+            hosts      = { "*.route.com" },
+            paths      = { "/path1" },
+          },
+          {
+            strip_path = true,
+            hosts      = { "plain.route.com" },
+            paths      = { "/path2" },
+          },
+        }
+      end)
+
+      lazy_teardown(function()
+        remove_routes(routes)
+      end)
+
+      it("matches wildcard host even when there is plain host", function()
+        local res = assert(proxy_client:send {
+          method  = "GET",
+          path    = "/path1",
+          headers = {
+            ["Host"]       = "plain.route.com",
+            ["kong-debug"] = 1,
+          }
+        })
+
+        assert.res_status(200, res)
+
+        assert.equal(routes[1].id,           res.headers["kong-route-id"])
+        assert.equal(routes[1].service.id,   res.headers["kong-service-id"])
+        assert.equal(routes[1].service.name, res.headers["kong-service-name"])
+      end)
+
+      it("matches plain host even when there is wildcard host", function()
+        local res = assert(proxy_client:send {
+          method  = "GET",
+          path    = "/path2",
+          headers = {
+            ["Host"]       = "plain.route.com",
+            ["kong-debug"] = 1,
+          }
+        })
+
+        assert.res_status(200, res)
+
+        assert.equal(routes[2].id,           res.headers["kong-route-id"])
+        assert.equal(routes[2].service.id,   res.headers["kong-service-id"])
+        assert.equal(routes[2].service.name, res.headers["kong-service-name"])
+      end)
+    end)
+
     describe("slash handing", function()
       local checks = {
         -- upstream url    paths           request path    expected path           strip uri