Add global Wine preferences tab

Phase 3 of the Wine/Proton stage (decisions 6, 9, 13, 19 in docs/testing/wine-proton.md): a global-only Wine tab modeled on the Pronunciation page, with the controller-only checkbox and a typed editable program list. Wine values flow through the preferences protocol so a global Apply reaches the live Wine settings from Phase 2 with no reader restart. Entries are validated as edited and named in-tab, blocking Apply until fixed; case-insensitive duplicates collapse. Per-application preferences expose no Wine editing and an app-scoped Apply cannot change the governing list.

internal/preferences/native.c

@@ -12,6 +12,16 @@ static const char *echoControls[] = {"echoRateScale", "echoPitchScale", "echoVol
                                      "echoSpeechServers", "echoSpeechFamilies"};
 // Borrowed from the builder for the duration of one Apply/OK request.
 static GtkWidget *busy_focus;
+// Apply and OK stay insensitive while the Wine tab names an invalid entry;
+// prefs_busy reapplies this alongside the busy/can-save state it owns.
+static int wine_valid = 1;
+static int busy_state;
+static int can_save_state;
+static void apply_sensitivity(void) {
+    gtk_widget_set_sensitive(prefs_widget("notebook"), !busy_state);
+    gtk_widget_set_sensitive(prefs_widget("apply"), !busy_state && wine_valid);
+    gtk_widget_set_sensitive(prefs_widget("save"), !busy_state && can_save_state && wine_valid);
+}
 void prefs_set_action(int value) { action = value; }
 GtkWidget *prefs_widget(const char *id) { return GTK_WIDGET(gtk_builder_get_object(builder, id)); }
 static void name_accessible_tree(AtkObject *object, const char *name) {
@@ -165,6 +175,7 @@ int prefs_init(const char *xml) {
     prefs_init_modifiers();
     prefs_init_interruption();
     prefs_init_pronunciation();
+    prefs_init_wine();
     prefs_init_text_attributes();
     prefs_init_tentacles();
     AtkObject *reading_accessible = gtk_widget_get_accessible(prefs_widget("readingSettingsTreeview"));
@@ -284,6 +295,9 @@ void prefs_set_application(const char *name) {
     // page entirely so application preferences expose no global controls.
     GtkNotebook *notebook = GTK_NOTEBOOK(prefs_widget("notebook"));
     gtk_notebook_remove_page(notebook, gtk_notebook_page_num(notebook, prefs_widget("tentacles_page")));
+    // Wine settings are global-only, so application preferences expose no
+    // Wine page at all.
+    gtk_notebook_remove_page(notebook, gtk_notebook_page_num(notebook, prefs_widget("wine_page")));
     gchar *title = g_strdup_printf("Cthulhu Preferences for %s", name);
     gtk_window_set_title(GTK_WINDOW(prefs_widget("window")), title);
     g_free(title);
@@ -300,14 +314,21 @@ int prefs_echo_preview(int *focused) {
     return result;
 }
 void prefs_busy(int busy, int can_save) {
-    gtk_widget_set_sensitive(prefs_widget("notebook"), !busy);
-    gtk_widget_set_sensitive(prefs_widget("apply"), !busy);
-    gtk_widget_set_sensitive(prefs_widget("save"), !busy && can_save);
+    busy_state = busy;
+    can_save_state = can_save;
+    apply_sensitivity();
     if (!busy && busy_focus) {
         if (gtk_widget_get_sensitive(busy_focus)) gtk_widget_grab_focus(busy_focus);
         busy_focus = NULL;
     }
 }
+void prefs_wine_validation(const char *message) {
+    gtk_label_set_text(GTK_LABEL(prefs_widget("wineValidationLabel")), message ? message : "");
+    atk_object_set_name(gtk_widget_get_accessible(prefs_widget("wineValidationLabel")),
+                        message && message[0] ? message : "Wine program validation");
+    wine_valid = !message || !message[0];
+    apply_sensitivity();
+}
 void prefs_present(void) { gtk_window_present(GTK_WINDOW(prefs_widget("window"))); }
 void prefs_close(void) { prefs_extensions_close(); busy_focus = NULL; gtk_widget_destroy(prefs_widget("window")); g_object_unref(builder); builder = NULL; }
 void prefs_status(const char *message, int focus) {

internal/preferences/native.h

@@ -53,6 +53,13 @@ void prefs_pronunciation_clear(void);
 void prefs_pronunciation_append(const char *word, const char *replacement);
 int prefs_pronunciation_count(void);
 char *prefs_pronunciation_value(int row, int column);
+void prefs_init_wine(void);
+void prefs_wine_clear(void);
+void prefs_wine_append(const char *program);
+int prefs_wine_count(void);
+char *prefs_wine_value(int row);
+int prefs_wine_changed(void);
+void prefs_wine_validation(const char *message);
 void prefs_init_text_attributes(void);
 void prefs_text_attributes_clear(void);
 void prefs_text_attribute_append(const char *key, const char *label, int speak, int braille);

internal/preferences/native_internal.h

@@ -15,6 +15,7 @@ void prefs_init_modifiers(void);
 void prefs_init_interruption(void);
 void prefs_init_reading_settings(void);
 void prefs_init_pronunciation(void);
+void prefs_init_wine(void);
 void prefs_init_text_attributes(void);
 void prefs_init_tentacles(void);
 #endif

internal/preferences/native_wine.c

@@ -0,0 +1,85 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+#include "native_internal.h"
+
+enum { PROGRAM };
+static GtkListStore *wine_programs;
+static int wine_changed;
+
+static void wine_edited(GtkCellRendererText *renderer, gchar *path, gchar *text, gpointer data) {
+    (void)renderer; (void)data;
+    GtkTreeIter iter;
+    if (gtk_tree_model_get_iter_from_string(GTK_TREE_MODEL(wine_programs), &iter, path)) {
+        gtk_list_store_set(wine_programs, &iter, PROGRAM, text, -1);
+        wine_changed = 1;
+    }
+}
+
+static void wine_add(GtkButton *button, gpointer data) {
+    (void)button; (void)data;
+    GtkTreeIter iter;
+    gtk_list_store_append(wine_programs, &iter);
+    gtk_list_store_set(wine_programs, &iter, PROGRAM, "", -1);
+    wine_changed = 1;
+    GtkTreePath *path = gtk_tree_model_get_path(GTK_TREE_MODEL(wine_programs), &iter);
+    GtkTreeView *view = GTK_TREE_VIEW(prefs_widget("wineTreeView"));
+    gtk_widget_grab_focus(GTK_WIDGET(view));
+    gtk_tree_view_set_cursor(view, path, gtk_tree_view_get_column(view, PROGRAM), TRUE);
+    gtk_tree_path_free(path);
+}
+
+static void wine_delete(GtkButton *button, gpointer data) {
+    (void)button; (void)data;
+    GtkTreeIter iter;
+    GtkTreeSelection *selection = gtk_tree_view_get_selection(GTK_TREE_VIEW(prefs_widget("wineTreeView")));
+    if (gtk_tree_selection_get_selected(selection, NULL, &iter)) {
+        gtk_list_store_remove(wine_programs, &iter);
+        wine_changed = 1;
+    }
+    gtk_widget_grab_focus(prefs_widget("wineTreeView"));
+}
+
+static gboolean wine_key(GtkWidget *widget, GdkEventKey *event, gpointer data) {
+    (void)data;
+    if (event->keyval != GDK_KEY_Return && event->keyval != GDK_KEY_KP_Enter && event->keyval != GDK_KEY_F2) return FALSE;
+    GtkTreePath *path = NULL;
+    GtkTreeViewColumn *column = NULL;
+    gtk_tree_view_get_cursor(GTK_TREE_VIEW(widget), &path, &column);
+    if (!path) return FALSE;
+    gtk_tree_view_set_cursor(GTK_TREE_VIEW(widget), path, column ? column : gtk_tree_view_get_column(GTK_TREE_VIEW(widget), 0), TRUE);
+    gtk_tree_path_free(path);
+    return TRUE;
+}
+
+void prefs_init_wine(void) {
+    GtkTreeView *view = GTK_TREE_VIEW(prefs_widget("wineTreeView"));
+    wine_programs = gtk_list_store_new(1, G_TYPE_STRING);
+    gtk_tree_view_set_model(view, GTK_TREE_MODEL(wine_programs));
+    GtkCellRenderer *renderer = gtk_cell_renderer_text_new();
+    g_object_set(renderer, "editable", TRUE, NULL);
+    g_signal_connect(renderer, "edited", G_CALLBACK(wine_edited), NULL);
+    gtk_tree_view_append_column(view, gtk_tree_view_column_new_with_attributes("Program", renderer, "text", PROGRAM, NULL));
+    atk_object_set_name(gtk_widget_get_accessible(GTK_WIDGET(view)), "Controller-only programs");
+    atk_object_set_description(gtk_widget_get_accessible(GTK_WIDGET(view)), "Select a cell and press Enter to edit it. Tab moves to the next control.");
+    g_signal_connect(view, "key-press-event", G_CALLBACK(wine_key), NULL);
+    g_signal_connect(prefs_widget("wineAddButton"), "clicked", G_CALLBACK(wine_add), NULL);
+    g_signal_connect(prefs_widget("wineDeleteButton"), "clicked", G_CALLBACK(wine_delete), NULL);
+    g_object_unref(wine_programs);
+}
+
+int prefs_wine_changed(void) { int result = wine_changed; wine_changed = 0; return result; }
+void prefs_wine_clear(void) { gtk_list_store_clear(wine_programs); }
+void prefs_wine_append(const char *program) {
+    GtkTreeIter iter;
+    gtk_list_store_append(wine_programs, &iter);
+    gtk_list_store_set(wine_programs, &iter, PROGRAM, program, -1);
+}
+int prefs_wine_count(void) { return gtk_tree_model_iter_n_children(GTK_TREE_MODEL(wine_programs), NULL); }
+char *prefs_wine_value(int row) {
+    GtkTreeIter iter;
+    if (!gtk_tree_model_iter_nth_child(GTK_TREE_MODEL(wine_programs), &iter, NULL, row)) return NULL;
+    char *value = NULL;
+    gtk_tree_model_get(GTK_TREE_MODEL(wine_programs), &iter, PROGRAM, &value, -1);
+    return value;
+}

internal/preferences/preferences.ui

@@ -317,6 +317,16 @@
               </object></child>
             </object></child>
             <child type="tab"><object class="GtkLabel"><property name="label">Tentacles</property></object></child>
+
+            <child><object class="GtkBox" id="wine_page"><property name="orientation">vertical</property><property name="border-width">12</property><property name="spacing">8</property>
+              <child><object class="GtkCheckButton" id="wineControllerOnlyCheckButton"><property name="label">_Controller-only mode for all Wine applications</property><property name="use-underline">True</property><property name="can-focus">True</property></object></child>
+              <child><object class="GtkLabel"><property name="label">Listed programs keep controller speech but lose standard control reading. Type executable names only, for example Game.exe. Do not type a path.</property><property name="wrap">True</property><property name="xalign">0</property></object></child>
+              <child><object class="GtkLabel" id="wineValidationLabel"><property name="label"></property><property name="wrap">True</property><property name="xalign">0</property></object></child>
+              <child><object class="GtkLabel"><property name="label">Controller-only _programs:</property><property name="use-underline">True</property><property name="mnemonic-widget">wineTreeView</property><property name="xalign">0</property></object></child>
+              <child><object class="GtkScrolledWindow"><property name="expand">True</property><child><object class="GtkTreeView" id="wineTreeView"><property name="can-focus">True</property></object></child></object></child>
+              <child><object class="GtkButtonBox"><property name="layout-style">end</property><child><object class="GtkButton" id="wineAddButton"><property name="label">_New</property><property name="use-underline">True</property><property name="can-focus">True</property></object></child><child><object class="GtkButton" id="wineDeleteButton"><property name="label">_Delete</property><property name="use-underline">True</property><property name="can-focus">True</property></object></child></object></child>
+            </object></child>
+            <child type="tab"><object class="GtkLabel"><property name="label">Wine</property></object></child>
           </object>
         </child>
         <child><object class="GtkLabel" id="status_label"><property name="label">_Status</property><property name="use-underline">True</property><property name="mnemonic-widget">status</property><property name="xalign">0</property></object></child>

internal/preferences/protocol.go

@@ -18,6 +18,9 @@ import (
 type Values struct {
 	StructuralNavigationTriggersFocusMode bool
 
+	// Wine is global-only: it is edited only in global preferences, and
+	// application preferences carry the base values through unchanged.
+	Wine                      config.WineSettings
 	Pronunciations            []config.PronunciationEntry
 	TextAttributes            config.TextAttributeSettings
 	OCR                       config.OCRSettings

internal/preferences/session.go

@@ -16,6 +16,8 @@ import (
 type uiSession struct {
 	extensionPages       []ExtensionPage
 	progressBar          config.ProgressBarSettings
+	wine                 config.WineSettings
+	wineEditable         bool
 	catalog              speech.Catalog
 	speechDefaults       speech.Settings
 	contractionTables    []braille.TableOption

internal/preferences/ui.go

@@ -64,7 +64,8 @@ func Run(ctx context.Context, input io.Reader, output io.Writer) error {
 		C.prefs_set_application(name)
 		C.free(unsafe.Pointer(name))
 	}
-	session := &uiSession{catalog: initial.Catalog, speechDefaults: initial.SpeechDefaults, soundThemes: []string{"default", "none"}}
+	session := &uiSession{catalog: initial.Catalog, speechDefaults: initial.SpeechDefaults, soundThemes: []string{"default", "none"},
+		wineEditable: initial.Application == ""}
 	session.setValues(initial.Values)
 	if err := session.set_extension_pages(initial.ExtensionPages); err != nil {
 		return err
@@ -182,6 +183,9 @@ func Run(ctx context.Context, input io.Reader, output io.Writer) error {
 				// The parent restores any active preview when this helper exits.
 				return nil
 			}
+			if session.wineEditable && C.prefs_wine_changed() != 0 {
+				session.refreshWineValidation()
+			}
 			if C.prefs_voice_changed() != 0 {
 				previewDirty = true
 			}

internal/preferences/ui_values.go

@@ -5,6 +5,13 @@
 package preferences
 
 func (session *uiSession) setValues(values Values) {
+	// The Wine page exists only in global preferences. Application
+	// preferences retain the values their base carries and submit them
+	// unchanged, so they are never a Wine editing surface.
+	session.wine = cloneWineSettings(values.Wine)
+	if session.wineEditable {
+		setWineValues(values.Wine)
+	}
 	setPronunciations(values.Pronunciations)
 	setTextAttributes(values.TextAttributes)
 	setOCRValues(values.OCR)
@@ -22,6 +29,13 @@ func (session *uiSession) setValues(values Values) {
 func (session *uiSession) getValues() (Values, error) {
 	var values Values
 	var err error
+	if session.wineEditable {
+		if values.Wine, err = getWineValues(); err != nil {
+			return values, err
+		}
+	} else {
+		values.Wine = cloneWineSettings(session.wine)
+	}
 	if values.Pronunciations, err = getPronunciations(); err != nil {
 		return values, err
 	}

internal/preferences/values.go

@@ -12,7 +12,7 @@ import (
 )
 
 func FromSettings(settings config.Settings) Values {
-	return Values{StructuralNavigationTriggersFocusMode: settings.StructuralNavigationTriggersFocusMode, OCR: settings.OCR, Pronunciations: append([]config.PronunciationEntry(nil), settings.Pronunciations...),
+	return Values{StructuralNavigationTriggersFocusMode: settings.StructuralNavigationTriggersFocusMode, Wine: cloneWineSettings(settings.Wine), OCR: settings.OCR, Pronunciations: append([]config.PronunciationEntry(nil), settings.Pronunciations...),
 		TextAttributes: config.TextAttributeSettings{Choices: append([]config.TextAttributeChoice(nil), settings.TextAttributes.Choices...), Indicator: settings.TextAttributes.Indicator},
 		KeyboardLayout: settings.KeyboardLayout, CthulhuModifierKeys: append([]string(nil), settings.CthulhuModifierKeys...),
 		KeyBindings: input.CloneBindingOverrides(settings.KeyBindings), TimeFormat: settings.TimeFormat, DateFormat: settings.DateFormat,
@@ -71,6 +71,14 @@ func FromSettings(settings config.Settings) Values {
 }
 
 func (values Values) Merge(settings config.Settings) (config.Settings, error) {
+	// Validate Wine before changing anything: an invalid entry is named and
+	// rejected here rather than silently dropped, so a rejected Apply leaves
+	// the governing settings untouched.
+	wine, err := normalizedWineSettings(values.Wine)
+	if err != nil {
+		return settings, err
+	}
+	settings.Wine = wine
 	settings.Pronunciations = append([]config.PronunciationEntry(nil), values.Pronunciations...)
 	settings.TextAttributes = config.TextAttributeSettings{Choices: append([]config.TextAttributeChoice(nil), values.TextAttributes.Choices...), Indicator: values.TextAttributes.Indicator}
 	settings.OCR = values.OCR

internal/preferences/wine.go

@@ -0,0 +1,112 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package preferences
+
+/*
+#include <stdlib.h>
+#include "native.h"
+*/
+import "C"
+
+import (
+	"fmt"
+	"strings"
+	"unsafe"
+
+	"git.stormux.org/storm/cthulhu/internal/config"
+)
+
+func cloneWineSettings(wine config.WineSettings) config.WineSettings {
+	wine.ExcludedPrograms = append([]string(nil), wine.ExcludedPrograms...)
+	return wine
+}
+
+// validateWinePrograms reports the first entry the Wine tab cannot accept,
+// naming it so the user can fix or delete exactly that entry. Config
+// validation remains the backstop for these rules.
+func validateWinePrograms(programs []string) error {
+	if len(programs) > 256 {
+		return fmt.Errorf("Wine program \"%s\" is entry %d. At most 256 programs can be listed; delete an entry.", programs[256], 257)
+	}
+	for index, name := range programs {
+		switch {
+		case strings.TrimSpace(name) == "":
+			return fmt.Errorf("Wine program entry %d is blank. Type an executable name such as Game.exe, or delete the entry.", index+1)
+		case strings.ContainsAny(name, `/\`):
+			return fmt.Errorf("Wine program \"%s\" is a path. Type only the executable name, such as Game.exe, or delete the entry.", name)
+		case len(name) > 255:
+			return fmt.Errorf("Wine program \"%s\" is too long. Executable names may be at most 255 characters; fix or delete the entry.", name)
+		case strings.TrimSpace(name) != name || strings.ContainsAny(name, "\x00\r\n"):
+			return fmt.Errorf("Wine program \"%s\" is not a valid executable name. Remove the surrounding spaces or control characters, or delete the entry.", name)
+		}
+	}
+	return nil
+}
+
+// collapseWinePrograms keeps the first spelling of each program and drops
+// later case-insensitive duplicates. An empty list stays nil so merged
+// settings keep their existing shape.
+func collapseWinePrograms(programs []string) []string {
+	var collapsed []string
+	seen := make(map[string]bool, len(programs))
+	for _, name := range programs {
+		key := strings.ToLower(name)
+		if seen[key] {
+			continue
+		}
+		seen[key] = true
+		collapsed = append(collapsed, name)
+	}
+	return collapsed
+}
+
+func normalizedWineSettings(wine config.WineSettings) (config.WineSettings, error) {
+	if err := validateWinePrograms(wine.ExcludedPrograms); err != nil {
+		return config.WineSettings{}, err
+	}
+	wine.ExcludedPrograms = collapseWinePrograms(wine.ExcludedPrograms)
+	return wine, nil
+}
+
+func setWineValidation(message string) {
+	text := C.CString(message)
+	defer C.free(unsafe.Pointer(text))
+	C.prefs_wine_validation(text)
+}
+
+func setWineValues(wine config.WineSettings) {
+	setCheck("wineControllerOnlyCheckButton", wine.ControllerOnly)
+	C.prefs_wine_clear()
+	for _, program := range wine.ExcludedPrograms {
+		name := C.CString(program)
+		C.prefs_wine_append(name)
+		C.free(unsafe.Pointer(name))
+	}
+	setWineValidation("")
+}
+
+func getWinePrograms() []string {
+	var programs []string
+	for row := 0; row < int(C.prefs_wine_count()); row++ {
+		name := C.prefs_wine_value(C.int(row))
+		programs = append(programs, C.GoString(name))
+		C.g_free(C.gpointer(name))
+	}
+	return programs
+}
+
+func (session *uiSession) refreshWineValidation() {
+	message := ""
+	if err := validateWinePrograms(getWinePrograms()); err != nil {
+		message = err.Error()
+	}
+	setWineValidation(message)
+}
+
+func getWineValues() (config.WineSettings, error) {
+	wine := config.WineSettings{ControllerOnly: getCheck("wineControllerOnlyCheckButton"),
+		ExcludedPrograms: getWinePrograms()}
+	return normalizedWineSettings(wine)
+}

internal/preferences/wine_test.go

@@ -0,0 +1,97 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package preferences
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+
+	"git.stormux.org/storm/cthulhu/internal/config"
+)
+
+func TestWineValuesRoundTripAndOwnership(t *testing.T) {
+	settings := config.DefaultSettings()
+	settings.Wine = config.WineSettings{ControllerOnly: true, ExcludedPrograms: []string{"Game.exe", "Another Game.exe"}}
+	values := FromSettings(settings)
+	if !reflect.DeepEqual(values.Wine, settings.Wine) {
+		t.Fatalf("Wine values = %+v", values.Wine)
+	}
+	values.Wine.ExcludedPrograms[0] = "Changed.exe"
+	if settings.Wine.ExcludedPrograms[0] != "Game.exe" {
+		t.Fatal("FromSettings aliases the Wine program list")
+	}
+	values.Wine.ExcludedPrograms[0] = "Game.exe"
+	values.Wine.ControllerOnly = false
+	values.Wine.ExcludedPrograms = append(values.Wine.ExcludedPrograms, "New Game.exe")
+	merged, err := values.Merge(settings)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := FromSettings(merged); !reflect.DeepEqual(got, values) {
+		t.Fatalf("Wine values did not round trip:\n got %+v\nwant %+v", got.Wine, values.Wine)
+	}
+	values.Wine.ExcludedPrograms[0] = "Changed.exe"
+	if merged.Wine.ExcludedPrograms[0] != "Game.exe" {
+		t.Fatal("merged Wine programs alias the UI values")
+	}
+}
+
+func TestWineValuesMergeCollapsesCaseInsensitiveDuplicates(t *testing.T) {
+	settings := config.DefaultSettings()
+	values := FromSettings(settings)
+	values.Wine.ExcludedPrograms = []string{"Game.exe", "game.EXE", "Other.exe", "GAME.exe", "other.exe"}
+	merged, err := values.Merge(settings)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := []string{"Game.exe", "Other.exe"}
+	if !reflect.DeepEqual(merged.Wine.ExcludedPrograms, want) {
+		t.Fatalf("collapsed Wine programs = %q, want %q", merged.Wine.ExcludedPrograms, want)
+	}
+	values.Wine.ExcludedPrograms = nil
+	merged, err = values.Merge(settings)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if merged.Wine.ExcludedPrograms != nil {
+		t.Fatalf("empty Wine list became %q, want nil", merged.Wine.ExcludedPrograms)
+	}
+}
+
+func TestWineValuesMergeRejectsInvalidEntriesByName(t *testing.T) {
+	overlong := strings.Repeat("a", 252) + ".exe"
+	cases := []struct {
+		name    string
+		entry   string
+		wantSub string
+	}{
+		{name: "windows path", entry: `C:\Games\Game.exe`, wantSub: `C:\Games\Game.exe`},
+		{name: "unix path", entry: "Games/Game.exe", wantSub: "Games/Game.exe"},
+		{name: "blank", entry: "", wantSub: "blank"},
+		{name: "spaces only", entry: "   ", wantSub: "blank"},
+		{name: "overlong", entry: overlong, wantSub: overlong},
+		{name: "leading space", entry: " Game.exe", wantSub: "Game.exe"},
+		{name: "trailing space", entry: "Game.exe ", wantSub: "Game.exe"},
+	}
+	for _, test := range cases {
+		t.Run(test.name, func(t *testing.T) {
+			settings := config.DefaultSettings()
+			settings.Wine.ExcludedPrograms = []string{"Kept.exe"}
+			values := FromSettings(settings)
+			values.Wine.ExcludedPrograms = []string{"Kept.exe", test.entry}
+			merged, err := values.Merge(settings)
+			if err == nil {
+				t.Fatalf("Merge accepted Wine entry %q", test.entry)
+			}
+			if !strings.Contains(err.Error(), test.wantSub) {
+				t.Fatalf("Merge error %q does not name %q", err, test.wantSub)
+			}
+			if !reflect.DeepEqual(merged.Wine.ExcludedPrograms, []string{"Kept.exe"}) {
+				t.Fatalf("rejected Merge changed Wine programs to %q", merged.Wine.ExcludedPrograms)
+			}
+		})
+	}
+}