web: drop phantom hidden bt for traditional on explicit submit, so 'no version -> nothing' works in trad too; v0.13.1

1 files changed, 20 insertions, 0 deletions

diff --git a/internal/web/server.go b/internal/web/server.go
index 6393076..7c90e9e 100644
--- a/internal/web/server.go
+++ b/internal/web/server.go
@@ -107,6 +107,17 @@ func requestVersions(cfg config.Config, r *http.Request) []string {
 	return []string{cfg.DefaultVersion}
 }
 
+// withoutVersion returns versions with every occurrence of drop removed.
+func withoutVersion(versions []string, drop string) []string {
+	kept := make([]string, 0, len(versions))
+	for _, v := range versions {
+		if v != drop {
+			kept = append(kept, v)
+		}
+	}
+	return kept
+}
+
 // queryBool reads a truthy/falsy query param ("1"/"true"/"on"/"yes" vs.
 // "0"/"false"/"off"/"no"), falling back to def when the param is absent or
 // unrecognized.
@@ -156,6 +167,15 @@ func resolveQuery(cfg config.Config, r *http.Request) (date, lectionary string,
 	lectionary = requestLectionary(cfg, r)
 	all = queryBool(r, "all", cfg.All)
 	versions = requestVersions(cfg, r)
+	// "bt" (the niedziela modern scrape) is invalid for the traditional
+	// lectionary and is hidden in the form -- but a box hidden by CSS stays
+	// checked, so switching modern->traditional carries a phantom v=bt that
+	// EffectiveVersions would substitute to wuj, defeating "no version selected
+	// -> nothing". On an explicit form submit (vset) drop that phantom bt; a
+	// fresh visit (no vset) keeps bt so its bt->wuj default still shows.
+	if lectionary == "traditional" && r.URL.Query().Has("vset") {
+		versions = withoutVersion(versions, "bt")
+	}
 	display = requestDisplay(cfg, r)
 	return date, lectionary, all, versions, display
 }