Add custom flag validation, as well as custom flag validation

examples/configs/gochan.example.json

@@ -42,6 +42,17 @@
 	],
 	"DefaultStyle": "pipes.css",
 
+	"CustomFlags": [
+		{"Flag":"california.png", "Name": "California"},
+		{"Flag":"cia.png", "Name": "CIA"},
+		{"Flag":"lgbtq.png", "Name": "LGBTQ"},
+		{"Flag":"ms-dos.png", "Name": "MS-DOS"},
+		{"Flag":"stallman.png", "Name": "Stallman"},
+		{"Flag":"templeos.png", "Name": "TempleOS"},
+		{"Flag":"tux.png", "Name": "Linux"},
+		{"Flag":"windows9x.png", "Name": "Windows 9x"}
+	],
+
 	"Banners": [
 		{"Filename": "gochan_go-parody.png", "Width": 300, "Height": 100}
 	],

pkg/config/config.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/Eggbertx/durationutil"
 	"github.com/gochan-org/gochan/pkg/gcutil"
+	"github.com/gochan-org/gochan/pkg/posting/geoip"
 )
 
 const (
@@ -232,10 +233,21 @@ type BoardConfig struct {
 	ThreadsPerPage         int
 	EnableGeoIP            bool
 	EnableNoFlag           bool
-	CustomFlags            map[string]string
+	CustomFlags            []geoip.Country
 	isGlobal               bool
 }
 
+// CheckFlag returns true if the given flag and name are configured for
+// the board (or are globally set)
+func (bc *BoardConfig) CheckFlag(flag string, name string) bool {
+	for _, country := range bc.CustomFlags {
+		if flag == country.Flag && name == country.Name {
+			return true
+		}
+	}
+	return false
+}
+
 // IsGlobal returns true if this is the global configuration applied to all
 // boards by default, or false if it is an explicitly configured board
 func (bc *BoardConfig) IsGlobal() bool {

pkg/posting/geoip/geoip.go

@@ -18,11 +18,14 @@ var (
 	ErrUnrecognized  = errors.New("unrecognized GeoIP handler ID")
 )
 
-// Country represents the GeoIP data used by gochan (the country/flag name and
-// country abbreviation/flag filename, accessible in /static/flags/{flag}).
+// Country represents the country data (or custom flag data) used by gochan.
+// For posts set to use the poster's country, `Flag` is the country's
+// abbreviation, and `Name` is the country name. If a custom flag is selected,
+// Flag is the filename accessible in /static/flags/{flag}, and Name is the
+// configured flag name. This package does not handle custom flag validation.
 type Country struct {
-	Name string
 	Flag string
+	Name string
 }
 
 // IsGeoIP is true of the country has a recognized abbreviation set as its