Reset master to testing content

internal/platform/session/session.go

@@ -0,0 +1,31 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+// Package session keeps desktop session policy independent of native backends.
+package session
+
+import (
+	"os"
+	"strings"
+)
+
+// Wayland respects an explicit session type; WAYLAND_DISPLAY is a fallback for
+// launchers that do not set XDG_SESSION_TYPE.
+func Wayland() bool {
+	kind := strings.ToLower(strings.TrimSpace(os.Getenv("XDG_SESSION_TYPE")))
+	if kind != "" {
+		return kind == "wayland"
+	}
+	return strings.TrimSpace(os.Getenv("WAYLAND_DISPLAY")) != ""
+}
+
+// GTKEnvironment preserves Xorg focus correlation in explicit X11 sessions.
+// Elsewhere GTK inherits the user's backend choice and selects its own default.
+func GTKEnvironment() []string {
+	environment := os.Environ()
+	if strings.EqualFold(strings.TrimSpace(os.Getenv("XDG_SESSION_TYPE")), "x11") {
+		environment = append(environment, "GDK_BACKEND=x11")
+	}
+	return environment
+}

internal/platform/session/session_test.go

@@ -0,0 +1,44 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package session
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestDesktopEnvironment(t *testing.T) {
+	for _, test := range []struct {
+		name, kind, display, backend, wantBackend string
+		wayland                                   bool
+	}{
+		{"Xorg", "x11", "", "wayland", "x11", false},
+		{"Xorg with inherited Wayland display", "x11", "wayland-0", "", "x11", false},
+		{"Wayland", "wayland", "wayland-0", "", "", true},
+		{"Wayland user backend", "wayland", "wayland-0", "x11", "x11", true},
+		{"normalized session", " Wayland ", "", "wayland,x11", "wayland,x11", true},
+		{"Wayland display fallback", "", "wayland-0", "", "", true},
+		{"unspecified session", "", "", "wayland,x11", "wayland,x11", false},
+		{"explicit other session", "tty", "wayland-0", "", "", false},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			t.Setenv("XDG_SESSION_TYPE", test.kind)
+			t.Setenv("WAYLAND_DISPLAY", test.display)
+			t.Setenv("GDK_BACKEND", test.backend)
+			t.Setenv("CTHULHU_TEST_INHERITED", "preserved")
+			if got := Wayland(); got != test.wayland {
+				t.Fatalf("Wayland = %v, want %v", got, test.wayland)
+			}
+			values := make(map[string]string)
+			for _, entry := range GTKEnvironment() {
+				key, value, _ := strings.Cut(entry, "=")
+				values[key] = value
+			}
+			if values["GDK_BACKEND"] != test.wantBackend || values["CTHULHU_TEST_INHERITED"] != "preserved" {
+				t.Fatalf("GTK backend = %q, inherited value = %q", values["GDK_BACKEND"], values["CTHULHU_TEST_INHERITED"])
+			}
+		})
+	}
+}