Reduce needed client restarts for settings changes.

fix a few GTK3 theming quirks

src/common/gtk3-theme-service.c

@@ -695,10 +695,15 @@ zoitechat_gtk3_theme_service_discover (void)
 		else
 			user_data_themes = g_build_filename (g_get_user_data_dir (), "themes", NULL);
 	}
+	/* Scan the app's own themes dir first: imported themes get a symlink
+	 * under the XDG data themes dir so GTK can resolve gtk-theme-name, and
+	 * scanning that link first would make the canonical-root dedup keep
+	 * the symlink path - changing the theme's path-derived id and breaking
+	 * the saved gui_gtk3_theme reference on the next start. */
+	add_theme_root (user_roots, seen_user_roots, user_dir);
 	add_theme_root (user_roots, seen_user_roots, user_data_themes);
 	g_free (user_data_themes);
 	add_theme_root (user_roots, seen_user_roots, home_themes);
-	add_theme_root (user_roots, seen_user_roots, user_dir);
 
 	{
 		const char *xdg_data_dirs = g_getenv ("XDG_DATA_DIRS");

src/fe-gtk/chanview.c

@@ -307,6 +307,109 @@ chanview_set_impl (chanview *cv, int type)
 		cv->func_focus (cv->focused);
 }
 
+void
+chanview_set_sorted (chanview *cv, gboolean sorted)
+{
+	cv->sorted = sorted ? 1 : 0;
+}
+
+void
+chanview_set_use_icons (chanview *cv, gboolean use_icons)
+{
+	cv->use_icons = use_icons ? 1 : 0;
+}
+
+void
+chanview_set_trunc_len (chanview *cv, int trunc_len)
+{
+	cv->trunc_len = trunc_len;
+}
+
+typedef struct
+{
+	chan *ch;
+	int old_pos;
+} chanview_sort_entry;
+
+/* re-sort the session rows below one parent with cb_compare, leaving
+ * utility rows (tag != 0) in place; mirrors chanview_insert_sorted() */
+static void
+chanview_resort_children (chanview *cv, GtkTreeIter *parent)
+{
+	GtkTreeModel *model = GTK_TREE_MODEL (cv->store);
+	GtkTreeIter iter;
+	chanview_sort_entry *entries;
+	int *positions;
+	gint *new_order;
+	chan *ch;
+	int n, i, j, count;
+
+	n = gtk_tree_model_iter_n_children (model, parent);
+	if (n < 2)
+		return;
+
+	entries = g_new0 (chanview_sort_entry, n);
+	positions = g_new0 (int, n);
+	new_order = g_new0 (gint, n);
+
+	count = 0;
+	for (i = 0; i < n; i++)
+	{
+		new_order[i] = i;
+		if (!gtk_tree_model_iter_nth_child (model, &iter, parent, i))
+			continue;
+		gtk_tree_model_get (model, &iter, COL_CHAN, &ch, -1);
+		if (ch && ch->tag == 0 && ch->userdata)
+		{
+			entries[count].ch = ch;
+			entries[count].old_pos = i;
+			positions[count] = i;
+			count++;
+		}
+	}
+
+	/* stable insertion sort; tab groups stay small so this is cheap */
+	for (i = 1; i < count; i++)
+	{
+		chanview_sort_entry key = entries[i];
+
+		j = i - 1;
+		while (j >= 0 && cv->cb_compare (entries[j].ch->userdata, key.ch->userdata) > 0)
+		{
+			entries[j + 1] = entries[j];
+			j--;
+		}
+		entries[j + 1] = key;
+	}
+
+	for (i = 0; i < count; i++)
+		new_order[positions[i]] = entries[i].old_pos;
+
+	gtk_tree_store_reorder (cv->store, parent, new_order);
+
+	g_free (entries);
+	g_free (positions);
+	g_free (new_order);
+}
+
+/* top-level rows keep their order (insertion never sorts them either);
+ * only the children within each family are sorted */
+void
+chanview_resort (chanview *cv)
+{
+	GtkTreeIter iter;
+
+	if (!cv->cb_compare)
+		return;
+
+	if (gtk_tree_model_get_iter_first (GTK_TREE_MODEL (cv->store), &iter))
+	{
+		do
+			chanview_resort_children (cv, &iter);
+		while (gtk_tree_model_iter_next (GTK_TREE_MODEL (cv->store), &iter));
+	}
+}
+
 static void
 chanview_free_ch (chanview *cv, GtkTreeIter *iter)
 {

src/fe-gtk/chanview.h

@@ -34,6 +34,10 @@ void chanview_set_callbacks (chanview *cv,
 	gboolean (*cb_contextmenu) (chanview *, chan *, int tag, void *userdata, GdkEventButton *),
 	int (*cb_compare) (void *a, void *b));
 void chanview_set_impl (chanview *cv, int type);
+void chanview_set_sorted (chanview *cv, gboolean sorted);
+void chanview_set_use_icons (chanview *cv, gboolean use_icons);
+void chanview_set_trunc_len (chanview *cv, int trunc_len);
+void chanview_resort (chanview *cv);
 chan *chanview_add (chanview *cv, char *name, void *family, void *userdata, gboolean allow_closure, int tag, GdkPixbuf *icon);
 int chanview_get_size (chanview *cv);
 GtkWidget *chanview_get_box (chanview *cv);

src/fe-gtk/maingui.c

@@ -569,6 +569,18 @@ mg_create_tab_colors (void)
         away_list = mg_attr_list_create (&gui_palette[THEME_TOKEN_TAB_AWAY], FALSE);
 }
 
+static PangoAttrList *
+mg_attr_list_for_tab_state (int state)
+{
+        if (state & TAB_STATE_NEW_HILIGHT)
+                return nickseen_list;
+        if (state & TAB_STATE_NEW_MSG)
+                return newmsg_list;
+        if (state & TAB_STATE_NEW_DATA)
+                return newdata_list;
+        return plain_list;
+}
+
 static void
 set_window_urgency (GtkWidget *win, gboolean set)
 {
@@ -714,7 +726,10 @@ mg_set_access_icon (session_gui *gui, GdkPixbuf *pix, gboolean away)
 {
         if (gui->op_xpm)
         {
-                if (pix == gtk_image_get_pixbuf (GTK_IMAGE (gui->op_xpm))) /* no change? */
+                /* no change? (the pref check makes sure a live settings
+                   change can still remove the icon) */
+                if (pix == gtk_image_get_pixbuf (GTK_IMAGE (gui->op_xpm)) &&
+                         prefs.hex_gui_input_icon)
                 {
                         mg_set_myself_away (gui, away);
                         return;
@@ -3596,6 +3611,48 @@ mg_create_topicbar (session *sess, GtkWidget *box)
 	mg_create_chanmodebuttons (gui, bbox);
 }
 
+/* re-apply the multi-line topic and inline mode button preferences to an
+ * already built topic bar (see mg_create_topicbar () for the layout) */
+
+static void
+mg_update_topicbar_layout (session_gui *gui)
+{
+	GtkWidget *topic = gui->topic_entry;
+	GtkWidget *vbox = gui->topic_bar;
+	GtkWidget *topic_scroll;
+	GtkWidget *hbox;
+	GtkWidget *mode_hbox;
+	GtkWidget *desired_parent;
+	GtkWidget *current_parent;
+	gboolean wrap;
+
+	if (!topic || !GTK_IS_TEXT_VIEW (topic) || !vbox || !gui->topicbutton_box)
+		return;
+
+	wrap = prefs.hex_gui_topicbar_multiline && !prefs.hex_gui_mode_buttons_inline;
+	gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (topic),
+		wrap ? GTK_WRAP_WORD_CHAR : GTK_WRAP_NONE);
+
+	topic_scroll = gtk_widget_get_parent (topic);
+	hbox = topic_scroll ? gtk_widget_get_parent (topic_scroll) : NULL;
+	mode_hbox = gtk_widget_get_parent (gui->topicbutton_box);
+
+	if (mode_hbox && hbox)
+	{
+		desired_parent = prefs.hex_gui_mode_buttons_inline ? hbox : vbox;
+		current_parent = gtk_widget_get_parent (mode_hbox);
+		if (current_parent && current_parent != desired_parent)
+		{
+			g_object_ref (mode_hbox);
+			gtk_container_remove (GTK_CONTAINER (current_parent), mode_hbox);
+			gtk_box_pack_start (GTK_BOX (desired_parent), mode_hbox, 0, 0, 0);
+			g_object_unref (mode_hbox);
+		}
+	}
+
+	mg_topicbar_update_height (topic);
+}
+
 /* check if a word is clickable */
 
 static int
@@ -4004,8 +4061,12 @@ mg_create_userlist (session_gui *gui, GtkWidget *box)
         gtk_widget_set_margin_end (gui->namelistinfo, 0);
         gtk_widget_set_hexpand (gui->namelistinfo, TRUE);
         gtk_widget_set_halign (gui->namelistinfo, GTK_ALIGN_FILL);
+        /* always pack it so the preference can be toggled without a
+           restart; visibility is controlled explicitly */
+        gtk_widget_set_no_show_all (gui->namelistinfo, TRUE);
+        gtk_box_pack_start (GTK_BOX (vbox), gui->namelistinfo, 0, 0, 0);
         if (prefs.hex_gui_ulist_count)
-                gtk_box_pack_start (GTK_BOX (vbox), gui->namelistinfo, 0, 0, 0);
+                gtk_widget_show (gui->namelistinfo);
 
         gui->user_tree = ulist = userlist_create (vbox);
 
@@ -4904,7 +4965,11 @@ mg_create_menu (session_gui *gui, GtkWidget *table, int away_state)
                                                                                         gui->menu_item);
         gtk_widget_set_hexpand (gui->menu, TRUE);
         gtk_widget_set_vexpand (gui->menu, FALSE);
-        gtk_widget_set_halign (gui->menu, GTK_ALIGN_START);
+        /* Fill the row: with GTK_ALIGN_START the menu bar stops after its
+         * last item and the rest of the row shows bare window background,
+         * which reads as a two-colored menu bar whenever the theme styles
+         * menubar and window differently. */
+        gtk_widget_set_halign (gui->menu, GTK_ALIGN_FILL);
         gtk_widget_set_valign (gui->menu, GTK_ALIGN_FILL);
         gtk_grid_attach (GTK_GRID (table), gui->menu, 0, 0, 3, 1);
 }
@@ -5229,6 +5294,10 @@ mg_apply_setup (void)
                 sess = list->data;
                 gtk_xtext_set_time_stamp (sess->res->buffer, prefs.hex_stamp_text);
                 ((xtext_buffer *)sess->res->buffer)->needs_recalc = TRUE;
+                /* the attribute lists were just recreated, so re-apply the
+                   color matching each tab's activity state */
+                if (sess->res->tab)
+                        chan_set_color (sess->res->tab, mg_attr_list_for_tab_state (sess->tab_state));
                 if (!sess->gui->is_tab || !done_main)
                         mg_place_userlist_and_chanview (sess->gui);
                 if (sess->gui->is_tab)
@@ -5271,6 +5340,49 @@ fe_buttons_update (session *sess)
                 gtk_widget_hide (sess->gui->button_box);
 }
 
+/* tab label for a session that has no joined channel: the channel we are
+ * waiting to join in parentheses, or "<none>". tbuf must hold CHANLEN+6. */
+
+static void
+mg_tab_pending_name (session *sess, char *tbuf)
+{
+        if (sess->waitchannel[0])
+        {
+                if (prefs.hex_gui_tab_trunc > 2 && g_utf8_strlen (sess->waitchannel, -1) > prefs.hex_gui_tab_trunc)
+                {
+                        /* truncate long channel names */
+                        tbuf[0] = '(';
+                        strcpy (tbuf + 1, sess->waitchannel);
+                        g_utf8_offset_to_pointer(tbuf, prefs.hex_gui_tab_trunc)[0] = 0;
+                        strcat (tbuf, "..)");
+                } else
+                {
+                        sprintf (tbuf, "(%s)", sess->waitchannel);
+                }
+        }
+        else
+                strcpy (tbuf, _("<none>"));
+}
+
+/* re-apply the tab label truncation preference to a session's tab */
+
+static void
+mg_retrunc_tab (session *sess)
+{
+        char tbuf[CHANLEN+6];
+
+        if (!sess->res->tab)
+                return;
+
+        if (sess->channel[0])
+                chan_rename (sess->res->tab, sess->channel, prefs.hex_gui_tab_trunc);
+        else
+        {
+                mg_tab_pending_name (sess, tbuf);
+                chan_rename (sess->res->tab, tbuf, prefs.hex_gui_tab_trunc);
+        }
+}
+
 void
 fe_clear_channel (session *sess)
 {
@@ -5279,22 +5391,7 @@ fe_clear_channel (session *sess)
 
         if (sess->gui->is_tab)
         {
-                if (sess->waitchannel[0])
-                {
-                        if (prefs.hex_gui_tab_trunc > 2 && g_utf8_strlen (sess->waitchannel, -1) > prefs.hex_gui_tab_trunc)
-                        {
-                                /* truncate long channel names */
-                                tbuf[0] = '(';
-                                strcpy (tbuf + 1, sess->waitchannel);
-                                g_utf8_offset_to_pointer(tbuf, prefs.hex_gui_tab_trunc)[0] = 0;
-                                strcat (tbuf, "..)");
-                        } else
-                        {
-                                sprintf (tbuf, "(%s)", sess->waitchannel);
-                        }
-                }
-                else
-                        strcpy (tbuf, _("<none>"));
+                mg_tab_pending_name (sess, tbuf);
                 chan_rename (sess->res->tab, tbuf, prefs.hex_gui_tab_trunc);
         }
 
@@ -5418,6 +5515,110 @@ fe_set_channel (session *sess)
                 chan_rename (sess->res->tab, sess->channel, prefs.hex_gui_tab_trunc);
 }
 
+static void
+mg_apply_live_prefs_to_gui (session_gui *gui, session *sess, const mg_live_prefs *changes)
+{
+        if (changes->meters)
+                mg_update_meters (gui);
+
+        if (changes->ulist_columns && gui->user_tree)
+                userlist_rebuild_columns (gui->user_tree);
+
+        if (changes->ulist_count && gui->namelistinfo)
+        {
+                if (prefs.hex_gui_ulist_count)
+                        gtk_widget_show (gui->namelistinfo);
+                else
+                        gtk_widget_hide (gui->namelistinfo);
+        }
+
+        if (changes->input_box && gui->nick_box)
+        {
+                if (prefs.hex_gui_input_nick)
+                        gtk_widget_show (gui->nick_box);
+                else
+                        gtk_widget_hide (gui->nick_box);
+        }
+
+        /* refresh the access icon; re-filling the user list rows can
+           clear it as a side effect, so restore it here too */
+        if ((changes->input_box || changes->ulist_rows) && sess && is_session (sess))
+        {
+                if (sess->type == SESS_DIALOG)
+                        mg_set_access_icon (gui, NULL, sess->server->is_away);
+                else
+                        mg_set_access_icon (gui, get_user_icon (sess->server, sess->me), sess->server->is_away);
+        }
+
+        if (changes->topic_bar)
+                mg_update_topicbar_layout (gui);
+
+        if (changes->transparency && gui->window)
+                gtk_widget_set_opacity (gui->window, (prefs.hex_gui_transparency / 255.));
+}
+
+/* apply preference changes that used to require a restart. called by
+ * setup.c after the new prefs have been committed. */
+
+void
+mg_apply_live_prefs (const mg_live_prefs *changes)
+{
+        GSList *list;
+        session *sess;
+        int done_main = FALSE;
+
+        if (!changes)
+                return;
+
+        /* the tab bar / channel tree lives in the shared tab window */
+        if (mg_gui && mg_gui->chanview)
+        {
+                if (changes->tab_resort)
+                {
+                        chanview_set_sorted (mg_gui->chanview, prefs.hex_gui_tab_sort);
+                        chanview_resort (mg_gui->chanview);
+                }
+                if (changes->tab_trunc)
+                        chanview_set_trunc_len (mg_gui->chanview, prefs.hex_gui_tab_trunc);
+                if (changes->chanview || changes->tab_resort)
+                {
+                        chanview_set_use_icons (mg_gui->chanview,
+                                                                                        prefs.hex_gui_tab_icons && (pix_tree_channel || pix_tree_dialog ||
+                                                                                                                                                                 pix_tree_server || pix_tree_util));
+                        /* rebuild the tab bar / tree widgets from the model */
+                        chanview_set_impl (mg_gui->chanview, prefs.hex_gui_tab_layout);
+                }
+        }
+
+        list = sess_list;
+        while (list)
+        {
+                sess = list->data;
+
+                if (changes->tab_trunc)
+                        mg_retrunc_tab (sess);
+                if (changes->ulist_sort)
+                        userlist_apply_sort (sess);
+                if (changes->ulist_rows)
+                        userlist_refill (sess);
+
+                if (sess->gui->is_tab)
+                {
+                        /* only apply to the shared tab window once, using the
+                           front-most session for session-dependent bits */
+                        if (!done_main)
+                        {
+                                done_main = TRUE;
+                                mg_apply_live_prefs_to_gui (sess->gui, current_tab, changes);
+                        }
+                }
+                else
+                        mg_apply_live_prefs_to_gui (sess->gui, sess, changes);
+
+                list = list->next;
+        }
+}
+
 void
 fe_set_typing (session *sess, const char *nick, const char *state)
 {

src/fe-gtk/maingui.h

@@ -37,6 +37,24 @@ GtkWidget *mg_create_generic_tab (char *name, char *title, int force_toplevel, i
 void mg_set_title (GtkWidget *button, char *title);
 void mg_set_access_icon (session_gui *gui, GdkPixbuf *pix, gboolean away);
 void mg_apply_setup (void);
+
+/* which parts of the GUI need a live rebuild after a preferences change */
+typedef struct
+{
+	unsigned int chanview:1;			/* rebuild the tab bar / channel tree */
+	unsigned int tab_resort:1;		/* re-sort channel tabs */
+	unsigned int tab_trunc:1;			/* re-truncate tab labels */
+	unsigned int ulist_columns:1;	/* rebuild user list columns */
+	unsigned int ulist_rows:1;		/* re-fill user list rows */
+	unsigned int ulist_sort:1;		/* re-apply user list sort order */
+	unsigned int ulist_count:1;		/* user count label visibility */
+	unsigned int meters:1;				/* rebuild lag/throttle meters */
+	unsigned int input_box:1;			/* nick box visibility and access icon */
+	unsigned int topic_bar:1;			/* topic wrap mode and mode button placement */
+	unsigned int transparency:1;	/* main window opacity */
+} mg_live_prefs;
+
+void mg_apply_live_prefs (const mg_live_prefs *changes);
 void mg_apply_session_font_prefs (session_gui *gui);
 void mg_close_sess (session *);
 void mg_tab_close (session *sess);

src/fe-gtk/meson.build

@@ -227,6 +227,20 @@ test('Theme Access Routing Tests', theme_access_tests,
   timeout: 120,
 )
 
+theme_gtk3_settings_tests = executable('theme_gtk3_settings_tests',
+  [
+    'theme/tests/test-theme-gtk3-settings.c',
+    'theme/theme-gtk3.c',
+  ],
+  include_directories: [config_h_include],
+  dependencies: [gtk_dep],
+)
+
+test('Theme GTK3 Settings Tests', theme_gtk3_settings_tests,
+  protocol: 'tap',
+  timeout: 120,
+)
+
 theme_preferences_gtk3_populate_tests = executable('theme_preferences_gtk3_populate_tests',
   'theme/tests/test-theme-preferences-gtk3-populate.c',
   include_directories: [config_h_include],

src/fe-gtk/setup.c

@@ -1045,28 +1045,30 @@ setup_create_spin (GtkWidget *table, int row, const setting *set)
         return wid;
 }
 
+static guint setup_trans_apply_tag = 0;
+/* the window opacity the dialog opened with, so cancelling can undo the
+ * live preview done by the slider */
+static int setup_transparency_snapshot;
+
 static gint
-setup_apply_trans (int *tag)
+setup_apply_trans (gpointer userdata)
 {
         prefs.hex_gui_transparency = setup_prefs.hex_gui_transparency;
-        gtk_widget_set_opacity (current_sess->gui->window,
-                                                        (prefs.hex_gui_transparency / 255.));
+        if (current_sess)
+                gtk_widget_set_opacity (current_sess->gui->window,
+                                                                (prefs.hex_gui_transparency / 255.));
 
-        *tag = 0;
+        setup_trans_apply_tag = 0;
         return 0;
 }
 
 static void
 setup_hscale_cb (GtkRange *wid, const setting *set)
 {
-        static int tag = 0;
-
         setup_set_int (&setup_prefs, set, (int) gtk_range_get_value (wid));
 
-        if (tag == 0)
-        {
-                tag = g_idle_add ((GSourceFunc) setup_apply_trans, &tag);
-        }
+        if (setup_trans_apply_tag == 0)
+                setup_trans_apply_tag = g_idle_add ((GSourceFunc) setup_apply_trans, NULL);
 }
 
 static void
@@ -1091,7 +1093,8 @@ setup_create_hscale (GtkWidget *table, int row, const setting *set)
 
 #ifndef WIN32 /* Windows always supports this */
         /* Only used for transparency currently */
-        if (!gdk_screen_is_composited (gtk_widget_get_screen (current_sess->gui->window)))
+        if (current_sess &&
+                 !gdk_screen_is_composited (gtk_widget_get_screen (current_sess->gui->window)))
                 gtk_widget_set_sensitive (wid, FALSE);
 #endif
 }
@@ -2293,7 +2296,9 @@ setup_apply (struct zoitechatprefs *pr)
 	ThemeChangedEvent event;
 	struct zoitechatprefs old_prefs = prefs;
 	int old_dark_mode = prefs.hex_gui_dark_mode;
+	mg_live_prefs live_changes;
 
+	memset (&live_changes, 0, sizeof (live_changes));
 
 #define DIFF(a) (pr->a != prefs.a)
 
@@ -2301,40 +2306,49 @@ setup_apply (struct zoitechatprefs *pr)
         if (DIFF (hex_gui_lang))
                 noapply = TRUE;
 #endif
-        if (DIFF (hex_gui_compact))
-                noapply = TRUE;
-        if (DIFF (hex_gui_input_icon))
-                noapply = TRUE;
-        if (DIFF (hex_gui_input_nick))
-                noapply = TRUE;
-        if (DIFF (hex_gui_lagometer))
-                noapply = TRUE;
-        if (DIFF (hex_gui_mode_buttons_inline))
-                noapply = TRUE;
-        if (DIFF (hex_gui_tab_icons))
-                noapply = TRUE;
-        if (DIFF (hex_gui_tab_closebuttons))
-                noapply = TRUE;
+        /* server tabs are only created when a connection is opened, so
+           existing connections keep their current tabs until a restart;
+           the channel tree indentation is still re-applied below */
         if (DIFF (hex_gui_tab_server))
+        {
                 noapply = TRUE;
-        if (DIFF (hex_gui_tab_small))
-                noapply = TRUE;
+                live_changes.chanview = TRUE;
+        }
+
+        if (DIFF (hex_gui_compact))
+        {
+                live_changes.chanview = TRUE;
+                live_changes.ulist_columns = TRUE;
+        }
+        if (DIFF (hex_gui_input_icon) || DIFF (hex_gui_input_nick))
+                live_changes.input_box = TRUE;
+        if (DIFF (hex_gui_lagometer) || DIFF (hex_gui_throttlemeter))
+                live_changes.meters = TRUE;
+        if (DIFF (hex_gui_mode_buttons_inline) || DIFF (hex_gui_topicbar_multiline))
+                live_changes.topic_bar = TRUE;
+        if (DIFF (hex_gui_tab_icons) || DIFF (hex_gui_tab_closebuttons) ||
+                 DIFF (hex_gui_tab_small))
+                live_changes.chanview = TRUE;
         if (DIFF (hex_gui_tab_sort))
-                noapply = TRUE;
+                live_changes.tab_resort = TRUE;
         if (DIFF (hex_gui_tab_trunc))
-                noapply = TRUE;
-        if (DIFF (hex_gui_throttlemeter))
-                noapply = TRUE;
-        if (DIFF (hex_gui_topicbar_multiline))
-                noapply = TRUE;
+                live_changes.tab_trunc = TRUE;
         if (DIFF (hex_gui_ulist_count))
-                noapply = TRUE;
+                live_changes.ulist_count = TRUE;
         if (DIFF (hex_gui_ulist_icons))
-                noapply = TRUE;
+                live_changes.ulist_rows = TRUE;
         if (DIFF (hex_gui_ulist_show_hosts))
-                noapply = TRUE;
+        {
+                live_changes.ulist_columns = TRUE;
+                live_changes.ulist_rows = TRUE; /* hostnames may be stale */
+        }
         if (DIFF (hex_gui_ulist_sort))
-                noapply = TRUE;
+                live_changes.ulist_sort = TRUE;
+        /* compare against the pre-dialog value: the slider previews the
+           opacity live on the current window only, so OK still needs to
+           apply it to the other windows */
+        if (pr->hex_gui_transparency != setup_transparency_snapshot)
+                live_changes.transparency = TRUE;
 
         if ((pr->hex_gui_tab_pos == 5 || pr->hex_gui_tab_pos == 6) &&
                  pr->hex_gui_tab_layout == 2 && pr->hex_gui_tab_pos != prefs.hex_gui_tab_pos)
@@ -2378,6 +2392,8 @@ setup_apply (struct zoitechatprefs *pr)
 
 	theme_manager_dispatch_setup_apply (&event);
 
+	mg_apply_live_prefs (&live_changes);
+
         if (noapply)
                 fe_message (_("Some settings were changed that require a"
                                                 " restart to take full effect."), FE_MSG_WARN);
@@ -2410,6 +2426,9 @@ setup_ok_cb (GtkWidget *but, GtkWidget *win)
         if (save_result.success)
         {
                 theme_preferences_stage_commit ();
+                /* the previewed values were accepted, so the close handler
+                   must not revert them */
+                setup_transparency_snapshot = prefs.hex_gui_transparency;
                 gtk_widget_destroy (win);
                 return;
         }
@@ -2472,6 +2491,24 @@ setup_close_cb (GtkWidget *win, GtkWidget **swin)
 {
         *swin = NULL;
 
+        /* drop any pending transparency preview and undo the previewed
+           opacity when the dialog is cancelled; after OK the snapshot
+           was updated so this is a no-op */
+        if (setup_trans_apply_tag)
+        {
+                g_source_remove (setup_trans_apply_tag);
+                setup_trans_apply_tag = 0;
+        }
+        if (prefs.hex_gui_transparency != setup_transparency_snapshot)
+        {
+                mg_live_prefs revert_changes;
+
+                prefs.hex_gui_transparency = setup_transparency_snapshot;
+                memset (&revert_changes, 0, sizeof (revert_changes));
+                revert_changes.transparency = TRUE;
+                mg_apply_live_prefs (&revert_changes);
+        }
+
         theme_preferences_stage_discard ();
 
         if (font_dialog)
@@ -2493,6 +2530,7 @@ setup_open (void)
         memcpy (&setup_prefs, &prefs, sizeof (prefs));
 
         color_change = FALSE;
+        setup_transparency_snapshot = prefs.hex_gui_transparency;
         theme_preferences_stage_begin ();
         setup_window = setup_window_open ();
 

src/fe-gtk/theme/tests/test-theme-access-routing.c

@@ -23,6 +23,7 @@
 #include <math.h>
 
 #include "../theme-access.h"
+#include "../theme-css.h"
 #include "../theme-manager.h"
 #include "../theme-runtime.h"
 #include "../../xtext-color.h"
@@ -54,6 +55,13 @@ setup_apply_real (const ThemeChangedEvent *event)
 	(void) event;
 }
 
+void
+gtkutil_append_font_css (GString *css, const PangoFontDescription *font_desc)
+{
+	(void) css;
+	(void) font_desc;
+}
+
 gboolean
 fe_dark_mode_is_enabled_for (unsigned int mode)
 {
@@ -173,6 +181,14 @@ theme_gtk3_is_active (void)
 	return stub_gtk3_active;
 }
 
+gboolean
+theme_gtk3_lookup_theme_color (const char *name, GdkRGBA *out_color)
+{
+	(void) name;
+	(void) out_color;
+	return FALSE;
+}
+
 static gboolean
 rgba_equal (const GdkRGBA *a, const GdkRGBA *b)
 {
@@ -336,6 +352,79 @@ test_access_xtext_palette_widget_mapping_when_gtk3_active (void)
 	g_object_unref (provider);
 }
 
+static void
+test_access_palette_css_does_not_feed_back_into_sampling (void)
+{
+	GtkWidget *window;
+	GtkWidget *label;
+	GtkCssProvider *theme1;
+	GtkCssProvider *theme2;
+	GdkScreen *screen;
+	XTextColor palette[2] = { 0 };
+	GdkRGBA old_bg;
+	GdkRGBA old_fg;
+	GdkRGBA expected;
+
+	if (!gtk_available)
+	{
+		g_test_message ("GTK display not available");
+		return;
+	}
+
+	reset_stubs ();
+	stub_gtk3_active = TRUE;
+	screen = gdk_screen_get_default ();
+	window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+	label = gtk_label_new ("mapped");
+	gtk_container_add (GTK_CONTAINER (window), label);
+	gtk_widget_realize (window);
+
+	/* Old GTK3 theme active at screen level. */
+	theme1 = gtk_css_provider_new ();
+	gtk_css_provider_load_from_data (theme1,
+		"label { color: #112233; background-color: #445566; }"
+		"label:selected { color: #778899; background-color: #aabbcc; }",
+		-1, NULL);
+	gtk_style_context_add_provider_for_screen (screen,
+		GTK_STYLE_PROVIDER (theme1), GTK_STYLE_PROVIDER_PRIORITY_USER);
+
+	/* The app paints the sampled theme colors onto the widget, like the
+	 * user list / channel tree / input box palette provider does. */
+	g_assert_true (gdk_rgba_parse (&old_bg, "#445566"));
+	g_assert_true (gdk_rgba_parse (&old_fg, "#112233"));
+	theme_css_apply_palette_widget (label, &old_bg, &old_fg, NULL);
+
+	/* The user switches to a new GTK3 theme. */
+	gtk_style_context_remove_provider_for_screen (screen, GTK_STYLE_PROVIDER (theme1));
+	theme2 = gtk_css_provider_new ();
+	gtk_css_provider_load_from_data (theme2,
+		"label { color: #00ff00; background-color: #ff0000; }"
+		"label:selected { color: #0000ff; background-color: #ffff00; }",
+		-1, NULL);
+	gtk_style_context_add_provider_for_screen (screen,
+		GTK_STYLE_PROVIDER (theme2), GTK_STYLE_PROVIDER_PRIORITY_USER);
+	gtk_style_context_reset_widgets (screen);
+
+	/* Re-sampling must see the new theme, not the palette colors the
+	 * app applied for the old theme. */
+	theme_get_xtext_colors_for_widget (label, palette, G_N_ELEMENTS (palette));
+
+	g_assert_true (stub_last_gtk_map_valid);
+	g_assert_true (gdk_rgba_parse (&expected, "#00ff00"));
+	g_assert_true (rgba_close (&stub_last_gtk_map.text_foreground, &expected));
+	g_assert_true (gdk_rgba_parse (&expected, "#ff0000"));
+	g_assert_true (rgba_close (&stub_last_gtk_map.text_background, &expected));
+
+	/* Sampling must not permanently strip the palette class. */
+	g_assert_true (gtk_style_context_has_class (gtk_widget_get_style_context (label),
+		theme_css_palette_class_name ()));
+
+	gtk_style_context_remove_provider_for_screen (screen, GTK_STYLE_PROVIDER (theme2));
+	gtk_widget_destroy (window);
+	g_object_unref (theme1);
+	g_object_unref (theme2);
+}
+
 static void
 test_access_dark_light_switch_affects_token_consumers (void)
 {
@@ -363,6 +452,8 @@ main (int argc, char **argv)
 	g_test_add_func ("/theme/access/xtext_palette_forwarding", test_access_xtext_palette_forwarding);
 	g_test_add_func ("/theme/access/xtext_palette_widget_mapping_when_gtk3_active",
 			 test_access_xtext_palette_widget_mapping_when_gtk3_active);
+	g_test_add_func ("/theme/access/palette_css_does_not_feed_back_into_sampling",
+			 test_access_palette_css_does_not_feed_back_into_sampling);
 	g_test_add_func ("/theme/access/widget_style_forwarding", test_access_widget_style_forwarding);
 	g_test_add_func ("/theme/access/dark_light_switch_affects_token_consumers",
 			 test_access_dark_light_switch_affects_token_consumers);

src/fe-gtk/theme/tests/test-theme-gtk3-settings.c

@@ -24,6 +24,7 @@
 #include <glib.h>
 #include <glib/gstdio.h>
 #include <gtk/gtk.h>
+#include <gio/gio.h>
 
 #include "../theme-gtk3.h"
 #include "../../../common/gtk3-theme-service.h"
@@ -39,11 +40,14 @@ static char *xdg_data_home;
 static char *theme_parent_root;
 static char *theme_child_root;
 static char *theme_switch_root;
+static char *theme_chrome_root;
+
+static gboolean stub_system_prefers_dark;
 
 gboolean
 theme_policy_system_prefers_dark (void)
 {
-	return FALSE;
+	return stub_system_prefers_dark;
 }
 
 static void
@@ -131,6 +135,8 @@ zoitechat_gtk3_theme_find_by_id (const char *theme_id)
 		return make_theme (theme_id, theme_child_root);
 	if (g_strcmp0 (theme_id, "switch") == 0)
 		return make_theme (theme_id, theme_switch_root);
+	if (g_strcmp0 (theme_id, "chrome") == 0)
+		return make_theme (theme_id, theme_chrome_root);
 	return NULL;
 }
 
@@ -177,6 +183,11 @@ zoitechat_gtk3_theme_build_inheritance_chain (const char *theme_root)
 		g_ptr_array_add (chain, g_strdup (theme_switch_root));
 		return chain;
 	}
+	if (g_strcmp0 (theme_root, theme_chrome_root) == 0)
+	{
+		g_ptr_array_add (chain, g_strdup (theme_chrome_root));
+		return chain;
+	}
 	g_ptr_array_unref (chain);
 	return NULL;
 }
@@ -247,6 +258,22 @@ setup_themes (void)
 		"gtk-enable-animations=false\n"
 		"gtk-cursor-blink-time=444\n");
 
+	theme_chrome_root = g_build_filename (temp_root, "chrome", NULL);
+	g_assert_cmpint (g_mkdir_with_parents (theme_chrome_root, 0700), ==, 0);
+	ensure_css_dir (theme_chrome_root, "gtk-3.24");
+	/* Defines named colors but no window/menubar/menu rules of its own,
+	 * so all chrome styling must come from the backfill provider. */
+	{
+		char *css = g_build_filename (theme_chrome_root, "gtk-3.24", "gtk.css", NULL);
+		write_file (css,
+			"@define-color theme_bg_color #e8f4e8;\n"
+			"@define-color theme_fg_color #102010;\n"
+			"@define-color theme_selected_bg_color #3465a4;\n"
+			"@define-color theme_selected_fg_color #ffffff;\n"
+			"label { color: #102010; }\n");
+		g_free (css);
+	}
+
 	path = g_build_filename (theme_parent_root, "index.theme", NULL);
 	write_file (path, "[Desktop Entry]\nName=parent\n");
 	g_free (path);
@@ -266,11 +293,13 @@ teardown_themes (void)
 	g_free (theme_parent_root);
 	g_free (theme_child_root);
 	g_free (theme_switch_root);
+	g_free (theme_chrome_root);
 	g_free (xdg_data_home);
 	g_free (temp_root);
 	theme_parent_root = NULL;
 	theme_child_root = NULL;
 	theme_switch_root = NULL;
+	theme_chrome_root = NULL;
 	xdg_data_home = NULL;
 	temp_root = NULL;
 }
@@ -343,6 +372,205 @@ test_settings_restored_on_disable_and_switch (void)
 	g_assert_false (theme_gtk3_is_active ());
 }
 
+static void
+test_follow_system_variant_resolves_to_theme_variant (void)
+{
+	GError *error = NULL;
+
+	if (!gtk_available)
+	{
+		g_test_message ("GTK display not available");
+		return;
+	}
+
+	/* An explicitly selected in-app theme must not follow the OS
+	 * light/dark preference: the legacy FOLLOW_SYSTEM variant resolves
+	 * to the variant the theme itself provides, so the window chrome
+	 * (menu bar) stays on the theme even when the system prefers dark. */
+	stub_system_prefers_dark = TRUE;
+	g_assert_true (theme_gtk3_apply ("switch", THEME_GTK3_VARIANT_FOLLOW_SYSTEM, &error));
+	g_assert_no_error (error);
+	g_assert_true (theme_gtk3_is_active ());
+	g_assert_cmpint (theme_gtk3_active_variant (), ==, THEME_GTK3_VARIANT_PREFER_LIGHT);
+	g_assert_false (get_bool_setting ("gtk-application-prefer-dark-theme"));
+
+	stub_system_prefers_dark = FALSE;
+	theme_gtk3_disable ();
+}
+
+static void
+test_menu_bar_follows_active_theme_colors (void)
+{
+	GError *error = NULL;
+	GtkWidget *window;
+	GtkWidget *menubar;
+	GtkStyleContext *context;
+	GdkRGBA bg;
+	GdkRGBA expected;
+
+	if (!gtk_available)
+	{
+		g_test_message ("GTK display not available");
+		return;
+	}
+
+	/* The chrome theme defines no menubar rules; without the backfill
+	 * provider the menu bar would fall through to the base (OS) theme
+	 * and follow the OS dark/light mode instead of the selected theme. */
+	g_assert_true (theme_gtk3_apply ("chrome", THEME_GTK3_VARIANT_PREFER_LIGHT, &error));
+	g_assert_no_error (error);
+
+	window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+	menubar = gtk_menu_bar_new ();
+	gtk_container_add (GTK_CONTAINER (window), menubar);
+	gtk_widget_show_all (window);
+
+	context = gtk_widget_get_style_context (menubar);
+	G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+	gtk_style_context_get_background_color (context, GTK_STATE_FLAG_NORMAL, &bg);
+	G_GNUC_END_IGNORE_DEPRECATIONS
+	g_assert_true (gdk_rgba_parse (&expected, "#e8f4e8"));
+	g_assert_cmpfloat (ABS (bg.red - expected.red), <, 0.01);
+	g_assert_cmpfloat (ABS (bg.green - expected.green), <, 0.01);
+	g_assert_cmpfloat (ABS (bg.blue - expected.blue), <, 0.01);
+
+	/* The window background must follow the theme too, or the space
+	 * around and beside the menu bar keeps the OS theme's colors. */
+	context = gtk_widget_get_style_context (window);
+	G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+	gtk_style_context_get_background_color (context, GTK_STATE_FLAG_NORMAL, &bg);
+	G_GNUC_END_IGNORE_DEPRECATIONS
+	g_assert_cmpfloat (ABS (bg.red - expected.red), <, 0.01);
+	g_assert_cmpfloat (ABS (bg.green - expected.green), <, 0.01);
+	g_assert_cmpfloat (ABS (bg.blue - expected.blue), <, 0.01);
+
+	gtk_widget_destroy (window);
+	theme_gtk3_disable ();
+}
+
+static void
+test_desktop_color_sync_does_not_leak_into_chrome (void)
+{
+	GError *error = NULL;
+	GtkWidget *window;
+	GtkWidget *menubar;
+	GtkStyleContext *context;
+	GtkCssProvider *desktop_css;
+	GdkScreen *screen;
+	GdkRGBA bg;
+	GdkRGBA expected;
+	GdkRGBA injected;
+
+	if (!gtk_available)
+	{
+		g_test_message ("GTK display not available");
+		return;
+	}
+
+	/* KDE's GTK color-scheme sync (~/.config/gtk-3.0/gtk.css) redefines
+	 * the standard named colors with the OS palette at USER priority.
+	 * The switch theme defines no named colors of its own, so a naive
+	 * @theme_bg_color reference in the chrome backfill would resolve to
+	 * the injected OS dark palette; the backfill must use its neutral
+	 * variant fallback instead. */
+	screen = gdk_screen_get_default ();
+	desktop_css = gtk_css_provider_new ();
+	gtk_css_provider_load_from_data (desktop_css,
+		"@define-color theme_bg_color #1e1e1e;\n"
+		"@define-color theme_fg_color #eeeeee;\n"
+		"menubar { background-color: #1e1e1e; }\n",
+		-1, NULL);
+	gtk_style_context_add_provider_for_screen (screen,
+		GTK_STYLE_PROVIDER (desktop_css), GTK_STYLE_PROVIDER_PRIORITY_USER);
+
+	g_assert_true (theme_gtk3_apply ("switch", THEME_GTK3_VARIANT_PREFER_LIGHT, &error));
+	g_assert_no_error (error);
+
+	{
+		GtkWidget *item;
+		GdkRGBA item_bg;
+
+		window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+		menubar = gtk_menu_bar_new ();
+		item = gtk_menu_item_new_with_label ("File");
+		gtk_menu_shell_append (GTK_MENU_SHELL (menubar), item);
+		gtk_container_add (GTK_CONTAINER (window), menubar);
+		gtk_widget_show_all (window);
+
+		context = gtk_widget_get_style_context (menubar);
+		G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+		gtk_style_context_get_background_color (context, GTK_STATE_FLAG_NORMAL, &bg);
+		G_GNUC_END_IGNORE_DEPRECATIONS
+		g_assert_true (gdk_rgba_parse (&expected, "#f6f5f4"));
+		g_assert_true (gdk_rgba_parse (&injected, "#1e1e1e"));
+		g_assert_cmpfloat (ABS (bg.red - injected.red), >, 0.1);
+		g_assert_cmpfloat (ABS (bg.red - expected.red), <, 0.01);
+		g_assert_cmpfloat (ABS (bg.green - expected.green), <, 0.01);
+		g_assert_cmpfloat (ABS (bg.blue - expected.blue), <, 0.01);
+
+		/* The menu bar body and the menu items must be one surface. */
+		context = gtk_widget_get_style_context (item);
+		G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+		gtk_style_context_get_background_color (context, GTK_STATE_FLAG_NORMAL, &item_bg);
+		G_GNUC_END_IGNORE_DEPRECATIONS
+		g_assert_cmpfloat (ABS (item_bg.red - bg.red), <, 0.01);
+		g_assert_cmpfloat (ABS (item_bg.green - bg.green), <, 0.01);
+		g_assert_cmpfloat (ABS (item_bg.blue - bg.blue), <, 0.01);
+	}
+
+	gtk_widget_destroy (window);
+	theme_gtk3_disable ();
+	gtk_style_context_remove_provider_for_screen (screen, GTK_STYLE_PROVIDER (desktop_css));
+	g_object_unref (desktop_css);
+}
+
+static void
+test_stale_theme_symlink_is_replaced (void)
+{
+	GError *error = NULL;
+	char *themes_dir;
+	char *link_path;
+	char *target;
+	char *active_theme_name = NULL;
+
+	if (!gtk_available)
+	{
+		g_test_message ("GTK display not available");
+		return;
+	}
+	if (!has_default_seat ())
+	{
+		g_test_message ("No default seat available");
+		return;
+	}
+
+	/* A dangling symlink left behind by a removed theme must not block
+	 * pinning gtk-theme-name to the newly applied theme. */
+	themes_dir = g_build_filename (xdg_data_home, "themes", NULL);
+	g_assert_cmpint (g_mkdir_with_parents (themes_dir, 0700), ==, 0);
+	link_path = g_build_filename (themes_dir, "switch", NULL);
+	g_unlink (link_path);
+	{
+		GFile *link_file = g_file_new_for_path (link_path);
+		g_assert_true (g_file_make_symbolic_link (link_file, "/nonexistent/switch", NULL, NULL));
+		g_object_unref (link_file);
+	}
+
+	g_assert_true (theme_gtk3_apply ("switch", THEME_GTK3_VARIANT_PREFER_LIGHT, &error));
+	g_assert_no_error (error);
+
+	target = g_file_read_link (link_path, NULL);
+	g_assert_cmpstr (target, ==, theme_switch_root);
+	g_object_get (gtk_settings_get_default (), "gtk-theme-name", &active_theme_name, NULL);
+	g_assert_cmpstr (active_theme_name, ==, "switch");
+
+	g_free (active_theme_name);
+	g_free (target);
+	g_free (link_path);
+	g_free (themes_dir);
+	theme_gtk3_disable ();
+}
+
 int
 main (int argc, char **argv)
 {
@@ -354,6 +582,14 @@ main (int argc, char **argv)
 
 	g_test_add_func ("/theme/gtk3/settings_layer_precedence", test_settings_layer_precedence);
 	g_test_add_func ("/theme/gtk3/settings_restored_on_disable_and_switch", test_settings_restored_on_disable_and_switch);
+	g_test_add_func ("/theme/gtk3/follow_system_variant_resolves_to_theme_variant",
+			 test_follow_system_variant_resolves_to_theme_variant);
+	g_test_add_func ("/theme/gtk3/menu_bar_follows_active_theme_colors",
+			 test_menu_bar_follows_active_theme_colors);
+	g_test_add_func ("/theme/gtk3/desktop_color_sync_does_not_leak_into_chrome",
+			 test_desktop_color_sync_does_not_leak_into_chrome);
+	g_test_add_func ("/theme/gtk3/stale_theme_symlink_is_replaced",
+			 test_stale_theme_symlink_is_replaced);
 
 	prefs.hex_gui_gtk3_variant = THEME_GTK3_VARIANT_PREFER_LIGHT;
 

src/fe-gtk/theme/tests/test-theme-gtk3-stub.c

@@ -89,3 +89,9 @@ theme_gtk3_is_active (void)
 {
 	return FALSE;
 }
+
+ThemeGtk3Variant
+theme_gtk3_active_variant (void)
+{
+	return THEME_GTK3_VARIANT_FOLLOW_SYSTEM;
+}

src/fe-gtk/theme/tests/test-theme-preferences-gtk3-populate.c

@@ -33,6 +33,7 @@ InputStyle *input_style;
 
 static gboolean gtk_available;
 static int apply_current_calls;
+static int set_token_color_calls;
 static char applied_theme_id[256];
 static ThemeGtk3Variant applied_variant;
 static gboolean removed_selected;
@@ -104,6 +105,7 @@ theme_manager_set_token_color (unsigned int dark_mode, ThemeSemanticToken token,
         (void)dark_mode;
         (void)token;
         (void)color;
+        set_token_color_calls++;
         if (changed)
                 *changed = FALSE;
 }
@@ -419,6 +421,43 @@ test_select_none_resets_theme_and_applies (void)
         gtk_widget_destroy (page);
 }
 
+static void
+test_select_theme_does_not_pin_palette_tokens (void)
+{
+        GtkWidget *page;
+        theme_preferences_ui *ui;
+        struct zoitechatprefs setup_prefs;
+
+        if (!gtk_available)
+        {
+                g_test_message ("GTK display not available");
+                return;
+        }
+
+        memset (&setup_prefs, 0, sizeof (setup_prefs));
+        memset (&prefs, 0, sizeof (prefs));
+        removed_selected = FALSE;
+        apply_current_calls = 0;
+        set_token_color_calls = 0;
+
+        page = theme_preferences_create_page (NULL, &setup_prefs, NULL);
+        ui = g_object_get_data (G_OBJECT (page), "theme-preferences-ui");
+        g_assert_nonnull (ui);
+
+        /* 0 = None, 1 = removed-theme, 2 = fallback-theme */
+        gtk_combo_box_set_active (GTK_COMBO_BOX (ui->gtk3_combo), 2);
+
+        g_assert_cmpstr (prefs.hex_gui_gtk3_theme, ==, "fallback-theme");
+        g_assert_cmpint (apply_current_calls, ==, 1);
+        /* Selecting a GTK3 theme must leave the mapped palette tokens
+         * unpinned so the user list, channel tree and input box keep
+         * resolving their colors from the active theme instead of being
+         * frozen until the next restart. */
+        g_assert_cmpint (set_token_color_calls, ==, 0);
+
+        gtk_widget_destroy (page);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -430,5 +469,7 @@ main (int argc, char **argv)
                          test_unset_theme_keeps_system_default_without_apply);
         g_test_add_func ("/theme/preferences/gtk3_select_none_resets_theme",
                          test_select_none_resets_theme_and_applies);
+        g_test_add_func ("/theme/preferences/gtk3_select_theme_does_not_pin_palette_tokens",
+                         test_select_theme_does_not_pin_palette_tokens);
         return g_test_run ();
 }

src/fe-gtk/theme/theme-access.c

@@ -20,6 +20,8 @@
 
 #include "theme-access.h"
 
+#include "theme-css.h"
+#include "theme-gtk3.h"
 #include "theme-runtime.h"
 
 
@@ -116,6 +118,17 @@ theme_access_lookup_named_color (GtkStyleContext *context, const char *const *na
 {
 	size_t i;
 
+	/* With an in-app GTK3 theme selected, prefer the colors resolved from
+	 * the theme itself: desktop integration CSS (e.g. KDE's color-scheme
+	 * sync) redefines the same named colors with the OS palette in the
+	 * widget cascade, which would drag OS dark/light colors into the
+	 * mapped palette. */
+	for (i = 0; names[i] != NULL; i++)
+	{
+		if (theme_gtk3_lookup_theme_color (names[i], out_color))
+			return TRUE;
+	}
+
 	for (i = 0; names[i] != NULL; i++)
 	{
 		if (gtk_style_context_lookup_color (context, names[i], out_color))
@@ -149,6 +162,8 @@ theme_access_get_gtk_palette_map (GtkWidget *widget, ThemeGtkPaletteMap *out_map
 	static const char *const selected_bg_fallbacks[] = { "theme_selected_bg_color", NULL };
 	static const char *const selected_fg_fallbacks[] = { "theme_selected_fg_color", NULL };
 	GtkStyleContext *context;
+	const char *palette_class;
+	gboolean had_palette_class;
 	GdkRGBA named;
 	GdkRGBA accent;
 
@@ -160,6 +175,16 @@ theme_access_get_gtk_palette_map (GtkWidget *widget, ThemeGtkPaletteMap *out_map
 	if (context == NULL)
 		return FALSE;
 
+	/* The application paints these widgets with fixed colors through the
+	 * zoitechat-palette provider.  Sampling must see the underlying GTK3
+	 * theme, not the colors we applied earlier: otherwise every theme
+	 * change reads back the previous palette and the user list, channel
+	 * tree and input box keep their stale colors until a restart. */
+	palette_class = theme_css_palette_class_name ();
+	had_palette_class = gtk_style_context_has_class (context, palette_class);
+	if (had_palette_class)
+		gtk_style_context_remove_class (context, palette_class);
+
 	theme_access_context_get_color (context, GTK_STATE_FLAG_NORMAL, &out_map->text_foreground);
 	theme_access_resolve_map_background (context, GTK_STATE_FLAG_NORMAL, base_fallbacks,
 					     &out_map->text_background);
@@ -173,6 +198,10 @@ theme_access_get_gtk_palette_map (GtkWidget *widget, ThemeGtkPaletteMap *out_map
 	if (accent.alpha <= 0.0)
 		accent = out_map->selection_background;
 	out_map->accent = accent;
+
+	if (had_palette_class)
+		gtk_style_context_add_class (context, palette_class);
+
 	out_map->enabled = TRUE;
 	return TRUE;
 }

src/fe-gtk/theme/theme-application.c

@@ -56,12 +56,11 @@ theme_application_apply_toplevel_theme (gboolean dark)
 
 	if (theme_gtk3_is_active ())
 	{
-		if (prefs.hex_gui_gtk3_variant == THEME_GTK3_VARIANT_PREFER_DARK)
-			prefer_dark = TRUE;
-		else if (prefs.hex_gui_gtk3_variant == THEME_GTK3_VARIANT_PREFER_LIGHT)
-			prefer_dark = FALSE;
-		else
-			prefer_dark = theme_policy_system_prefers_dark ();
+		/* An explicitly selected in-app theme controls its own
+		 * variant; the OS light/dark preference must not leak into
+		 * the window chrome (menu bar, dialogs).  The active variant
+		 * is always resolved to light or dark. */
+		prefer_dark = theme_gtk3_active_variant () == THEME_GTK3_VARIANT_PREFER_DARK;
 	}
 	else
 	{

src/fe-gtk/theme/theme-css.c

@@ -60,6 +60,12 @@ typedef struct
 static GtkCssProvider *theme_css_input_provider;
 static ThemeCssInputFingerprint theme_css_input_fp;
 
+const char *
+theme_css_palette_class_name (void)
+{
+	return theme_css_selector_palette_class;
+}
+
 void
 theme_css_apply_app_provider (GtkStyleProvider *provider)
 {

src/fe-gtk/theme/theme-css.h

@@ -30,6 +30,7 @@
  * theme_css_apply_widget_provider:
  * Use for widget-local CSS providers attached to a specific widget context.
  */
+const char *theme_css_palette_class_name (void);
 void theme_css_apply_app_provider (GtkStyleProvider *provider);
 void theme_css_remove_app_provider (GtkStyleProvider *provider);
 void theme_css_apply_widget_provider (GtkWidget *widget, GtkStyleProvider *provider);

src/fe-gtk/theme/theme-gtk3.c

@@ -33,11 +33,60 @@
 
 static GPtrArray *theme_gtk3_providers_base;
 static GPtrArray *theme_gtk3_providers_variant;
+static GtkCssProvider *theme_gtk3_chrome_provider;
+static GHashTable *theme_gtk3_theme_colors;
 static GHashTable *theme_gtk3_provider_cache;
 static gboolean theme_gtk3_active;
 static char *theme_gtk3_current_id;
 static ThemeGtk3Variant theme_gtk3_current_variant;
 
+/* Menu bar and menus fall back to the base gtk-theme-name theme (the OS
+ * theme) for any property the selected in-app theme's CSS does not define,
+ * which mixes OS dark/light colors into the chrome (issue: dark menu bar on
+ * a light in-app theme when the OS is in dark mode).  While an in-app theme
+ * is active, backfill those widgets with the theme's own named colors.  The
+ * provider sits just below the theme providers, so a theme that styles its
+ * menus keeps full control. */
+#define THEME_GTK3_CHROME_PRIORITY (GTK_STYLE_PROVIDER_PRIORITY_USER - 1)
+/* Concrete color values are formatted in: desktop integration CSS (e.g.
+ * KDE's color-scheme sync in ~/.config/gtk-3.0/gtk.css) redefines the
+ * standard named colors with the OS palette at USER priority, so a
+ * "@theme_bg_color" reference here would resolve to the OS dark/light
+ * colors instead of the selected theme's. */
+static const char theme_gtk3_chrome_css_template[] =
+	".background, .background:backdrop {"
+	" background-color: %s;"
+	" color: %s;"
+	"}"
+	"headerbar, headerbar:backdrop, .titlebar, .titlebar:backdrop {"
+	" background-color: %s;"
+	" background-image: none;"
+	" color: %s;"
+	"}";
+
+/* The menu bar body and the menu items are separate CSS surfaces; desktop
+ * integration CSS or a theme can style one but not the other, splitting
+ * the menu bar row into two colors.  These rules sit above the theme and
+ * the desktop CSS so body and items always render as one surface. */
+#define THEME_GTK3_MENU_UNIFORM_PRIORITY (GTK_STYLE_PROVIDER_PRIORITY_USER + 40)
+static const char theme_gtk3_menu_uniform_template[] =
+	"menubar, menubar:backdrop, menubar > menuitem, menubar > menuitem:backdrop,"
+	"menu, menu:backdrop, .menu, .menu:backdrop, menu > menuitem, menu > menuitem:backdrop {"
+	" background-color: %s;"
+	" background-image: none;"
+	" color: %s;"
+	"}"
+	"menubar > menuitem:hover, menubar > menuitem:selected,"
+	"menu > menuitem:hover, menu > menuitem:selected,"
+	".menu menuitem:hover, .menu menuitem:selected {"
+	" background-color: %s;"
+	" background-image: none;"
+	" color: %s;"
+	"}"
+	"menubar > menuitem:disabled, menu > menuitem:disabled {"
+	" color: alpha(%s, 0.5);"
+	"}";
+
 typedef struct
 {
 	GHashTable *defaults;
@@ -49,6 +98,7 @@ typedef struct
 static ThemeGtk3SettingsState theme_gtk3_settings_state;
 
 static gboolean settings_apply_property (GtkSettings *settings, const char *property_name, const char *raw_value);
+static void theme_gtk3_menu_uniform_apply (const char *bg, const char *fg, const char *sel_bg, const char *sel_fg);
 
 static gboolean
 theme_gtk3_theme_name_is_dark (const char *name)
@@ -399,6 +449,21 @@ settings_theme_link_search_path (const char *theme_root, const char *theme_name)
 	}
 
 	link_path = g_build_filename (themes_root, theme_name, NULL);
+
+	/* A leftover symlink from a removed or relocated theme would satisfy
+	 * the EXISTS check while pointing at the wrong (or no) theme, leaving
+	 * the base gtk-theme-name on the OS theme.  Replace it. */
+	{
+		char *link_target = g_file_read_link (link_path, NULL);
+		if (link_target)
+		{
+			if (g_strcmp0 (link_target, theme_root) != 0 ||
+			    !g_file_test (link_path, G_FILE_TEST_IS_DIR))
+				g_unlink (link_path);
+			g_free (link_target);
+		}
+	}
+
 	if (!g_file_test (link_path, G_FILE_TEST_EXISTS))
 	{
 		GFile *link_file = g_file_new_for_path (link_path);
@@ -757,12 +822,176 @@ settings_apply_from_file (const char *theme_root, const char *css_dir)
 	g_ptr_array_unref (settings_paths);
 }
 
+static gboolean
+theme_gtk3_providers_define_color (const char *name)
+{
+	char *needle = g_strdup_printf ("@define-color %s ", name);
+	gboolean found = FALSE;
+	guint i;
+
+	for (i = 0; !found && theme_gtk3_providers_base && i < theme_gtk3_providers_base->len; i++)
+	{
+		char *dump = gtk_css_provider_to_string (g_ptr_array_index (theme_gtk3_providers_base, i));
+		found = dump && strstr (dump, needle) != NULL;
+		g_free (dump);
+	}
+	for (i = 0; !found && theme_gtk3_providers_variant && i < theme_gtk3_providers_variant->len; i++)
+	{
+		char *dump = gtk_css_provider_to_string (g_ptr_array_index (theme_gtk3_providers_variant, i));
+		found = dump && strstr (dump, needle) != NULL;
+		g_free (dump);
+	}
+
+	g_free (needle);
+	return found;
+}
+
+/* Resolve a named color from the selected theme itself.  The lookup
+ * context layers the theme's providers over the screen cascade, so the
+ * theme's own @define-color wins; when the theme does not define the
+ * name at all, fall back to a neutral palette matching the theme's
+ * variant instead of whatever the desktop injected into the cascade. */
+static char *
+theme_gtk3_chrome_resolve_color (GtkStyleContext *lookup, const char *name, const char *fallback)
+{
+	GdkRGBA color;
+
+	if (!theme_gtk3_providers_define_color (name) ||
+	    !gtk_style_context_lookup_color (lookup, name, &color))
+		g_assert (gdk_rgba_parse (&color, fallback));
+
+	if (!theme_gtk3_theme_colors)
+		theme_gtk3_theme_colors = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
+	{
+		GdkRGBA *stored = g_new (GdkRGBA, 1);
+		*stored = color;
+		g_hash_table_insert (theme_gtk3_theme_colors, g_strdup (name), stored);
+	}
+
+	return gdk_rgba_to_string (&color);
+}
+
+gboolean
+theme_gtk3_lookup_theme_color (const char *name, GdkRGBA *out_color)
+{
+	GdkRGBA *stored;
+
+	if (!theme_gtk3_active || !theme_gtk3_theme_colors || !name || !out_color)
+		return FALSE;
+
+	stored = g_hash_table_lookup (theme_gtk3_theme_colors, name);
+	if (!stored)
+		return FALSE;
+
+	*out_color = *stored;
+	return TRUE;
+}
+
+static void
+theme_gtk3_chrome_provider_apply (gboolean prefer_dark)
+{
+	GdkScreen *screen = gdk_screen_get_default ();
+	GtkStyleContext *lookup;
+	char *bg;
+	char *fg;
+	char *sel_bg;
+	char *sel_fg;
+	char *css;
+	guint i;
+
+	if (!screen)
+		return;
+
+	lookup = gtk_style_context_new ();
+	for (i = 0; theme_gtk3_providers_base && i < theme_gtk3_providers_base->len; i++)
+		gtk_style_context_add_provider (lookup,
+			GTK_STYLE_PROVIDER (g_ptr_array_index (theme_gtk3_providers_base, i)),
+			GTK_STYLE_PROVIDER_PRIORITY_USER);
+	for (i = 0; theme_gtk3_providers_variant && i < theme_gtk3_providers_variant->len; i++)
+		gtk_style_context_add_provider (lookup,
+			GTK_STYLE_PROVIDER (g_ptr_array_index (theme_gtk3_providers_variant, i)),
+			GTK_STYLE_PROVIDER_PRIORITY_USER);
+
+	if (theme_gtk3_theme_colors)
+		g_hash_table_remove_all (theme_gtk3_theme_colors);
+
+	bg = theme_gtk3_chrome_resolve_color (lookup, "theme_bg_color",
+					      prefer_dark ? "#242424" : "#f6f5f4");
+	fg = theme_gtk3_chrome_resolve_color (lookup, "theme_fg_color",
+					      prefer_dark ? "#eeeeee" : "#2e3436");
+	sel_bg = theme_gtk3_chrome_resolve_color (lookup, "theme_selected_bg_color", "#3584e4");
+	sel_fg = theme_gtk3_chrome_resolve_color (lookup, "theme_selected_fg_color", "#ffffff");
+	/* Not used by the chrome CSS itself, but resolved and stored for the
+	 * mapped-palette sampling fallback (chat area and friends). */
+	g_free (theme_gtk3_chrome_resolve_color (lookup, "theme_base_color",
+						 prefer_dark ? "#1e1e1e" : "#ffffff"));
+	g_object_unref (lookup);
+
+	css = g_strdup_printf (theme_gtk3_chrome_css_template,
+			       bg, fg,
+			       bg, fg);
+
+	if (!theme_gtk3_chrome_provider)
+		theme_gtk3_chrome_provider = gtk_css_provider_new ();
+	gtk_css_provider_load_from_data (theme_gtk3_chrome_provider, css, -1, NULL);
+
+	gtk_style_context_add_provider_for_screen (screen,
+		GTK_STYLE_PROVIDER (theme_gtk3_chrome_provider),
+		THEME_GTK3_CHROME_PRIORITY);
+
+	theme_gtk3_menu_uniform_apply (bg, fg, sel_bg, sel_fg);
+
+	g_free (css);
+	g_free (sel_fg);
+	g_free (sel_bg);
+	g_free (fg);
+	g_free (bg);
+}
+
+static GtkCssProvider *theme_gtk3_menu_uniform_provider;
+
+static void
+theme_gtk3_menu_uniform_apply (const char *bg, const char *fg, const char *sel_bg, const char *sel_fg)
+{
+	GdkScreen *screen = gdk_screen_get_default ();
+	char *css;
+
+	if (!screen)
+		return;
+
+	css = g_strdup_printf (theme_gtk3_menu_uniform_template, bg, fg, sel_bg, sel_fg, fg);
+	if (!theme_gtk3_menu_uniform_provider)
+		theme_gtk3_menu_uniform_provider = gtk_css_provider_new ();
+	gtk_css_provider_load_from_data (theme_gtk3_menu_uniform_provider, css, -1, NULL);
+	gtk_style_context_add_provider_for_screen (screen,
+		GTK_STYLE_PROVIDER (theme_gtk3_menu_uniform_provider),
+		THEME_GTK3_MENU_UNIFORM_PRIORITY);
+	g_free (css);
+}
+
+static void
+theme_gtk3_chrome_provider_remove (void)
+{
+	GdkScreen *screen = gdk_screen_get_default ();
+
+	if (!screen)
+		return;
+
+	if (theme_gtk3_chrome_provider)
+		gtk_style_context_remove_provider_for_screen (screen,
+			GTK_STYLE_PROVIDER (theme_gtk3_chrome_provider));
+	if (theme_gtk3_menu_uniform_provider)
+		gtk_style_context_remove_provider_for_screen (screen,
+			GTK_STYLE_PROVIDER (theme_gtk3_menu_uniform_provider));
+}
+
 static void
 theme_gtk3_remove_provider (void)
 {
 	GdkScreen *screen = gdk_screen_get_default ();
 	guint i;
 
+	theme_gtk3_chrome_provider_remove ();
 	if (screen && theme_gtk3_providers_variant)
 	{
 		for (i = 0; i < theme_gtk3_providers_variant->len; i++)
@@ -866,6 +1095,7 @@ load_css_with_variant (ZoitechatGtk3Theme *theme, ThemeGtk3Variant variant, GErr
 	}
 
 	g_ptr_array_unref (chain);
+	theme_gtk3_chrome_provider_apply (prefer_dark);
 	settings_apply_for_variant (variant);
 	theme_gtk3_reset_widgets ();
 	theme_gtk3_active = TRUE;
@@ -876,24 +1106,35 @@ static gboolean
 theme_gtk3_apply_internal (const char *theme_id, ThemeGtk3Variant variant, gboolean force_reload, GError **error)
 {
 	ZoitechatGtk3Theme *theme;
-	char *previous_id = g_strdup (theme_gtk3_current_id);
-	ThemeGtk3Variant previous_variant = theme_gtk3_current_variant;
-	gboolean had_previous = theme_gtk3_active && previous_id && previous_id[0];
+	char *previous_id;
+	ThemeGtk3Variant previous_variant;
+	gboolean had_previous;
 	gboolean ok;
 
+	theme = zoitechat_gtk3_theme_find_by_id (theme_id);
+	if (!theme)
+		return g_set_error_literal (error, G_FILE_ERROR, G_FILE_ERROR_NOENT, "GTK3 theme not found."), FALSE;
+
+	/* An explicitly selected in-app theme pins the rendering to that
+	 * theme: it must not flip with the OS light/dark preference.  Legacy
+	 * configs still carry FOLLOW_SYSTEM (the pre-inference default), so
+	 * resolve it to the variant the theme itself provides. */
+	if (variant == THEME_GTK3_VARIANT_FOLLOW_SYSTEM)
+		variant = theme_gtk3_infer_variant (theme);
+
 	if (!force_reload &&
 		theme_gtk3_active &&
 		g_strcmp0 (theme_gtk3_current_id, theme_id) == 0 &&
 		theme_gtk3_current_variant == variant)
-		return TRUE;
-
-	theme = zoitechat_gtk3_theme_find_by_id (theme_id);
-	if (!theme)
 	{
-		g_free (previous_id);
-		return g_set_error_literal (error, G_FILE_ERROR, G_FILE_ERROR_NOENT, "GTK3 theme not found."), FALSE;
+		zoitechat_gtk3_theme_free (theme);
+		return TRUE;
 	}
 
+	previous_id = g_strdup (theme_gtk3_current_id);
+	previous_variant = theme_gtk3_current_variant;
+	had_previous = theme_gtk3_active && previous_id && previous_id[0];
+
 	theme_gtk3_remove_provider ();
 	if (force_reload)
 		theme_gtk3_invalidate_provider_cache ();
@@ -961,6 +1202,12 @@ void
 theme_gtk3_disable (void)
 {
 	theme_gtk3_remove_provider ();
+	g_clear_object (&theme_gtk3_chrome_provider);
+	g_clear_pointer (&theme_gtk3_theme_colors, g_hash_table_destroy);
+	/* Following the system theme: keep the menu bar body and the menu
+	 * items on one surface too, using the system's own colors. */
+	theme_gtk3_menu_uniform_apply ("@theme_bg_color", "@theme_fg_color",
+				       "@theme_selected_bg_color", "@theme_selected_fg_color");
 	g_clear_pointer (&theme_gtk3_current_id, g_free);
 	theme_gtk3_invalidate_provider_cache ();
 	g_clear_pointer (&theme_gtk3_provider_cache, g_hash_table_destroy);
@@ -990,3 +1237,13 @@ theme_gtk3_is_active (void)
 {
 	return theme_gtk3_active;
 }
+
+ThemeGtk3Variant
+theme_gtk3_active_variant (void)
+{
+	/* Always resolved to PREFER_LIGHT or PREFER_DARK while a theme is
+	 * active; FOLLOW_SYSTEM only when no in-app theme is applied. */
+	if (!theme_gtk3_active)
+		return THEME_GTK3_VARIANT_FOLLOW_SYSTEM;
+	return theme_gtk3_current_variant;
+}

src/fe-gtk/theme/theme-gtk3.h

@@ -22,6 +22,7 @@
 #define ZOITECHAT_THEME_GTK3_H
 
 #include <glib.h>
+#include <gdk/gdk.h>
 
 typedef enum
 {
@@ -38,5 +39,7 @@ ThemeGtk3Variant theme_gtk3_variant_for_theme (const char *theme_id);
 void theme_gtk3_invalidate_provider_cache (void);
 void theme_gtk3_disable (void);
 gboolean theme_gtk3_is_active (void);
+ThemeGtk3Variant theme_gtk3_active_variant (void);
+gboolean theme_gtk3_lookup_theme_color (const char *name, GdkRGBA *out_color);
 
 #endif

src/fe-gtk/theme/theme-manager.c

@@ -590,11 +590,7 @@ theme_manager_apply_platform_window_theme (GtkWidget *window)
 
 	context = gtk_widget_get_style_context (window);
 	if (theme_gtk3_is_active ())
-	{
-		dark = prefs.hex_gui_gtk3_variant == THEME_GTK3_VARIANT_PREFER_DARK;
-		if (prefs.hex_gui_gtk3_variant == THEME_GTK3_VARIANT_FOLLOW_SYSTEM)
-			dark = theme_policy_system_prefers_dark ();
-	}
+		dark = theme_gtk3_active_variant () == THEME_GTK3_VARIANT_PREFER_DARK;
 	else
 		dark = theme_policy_is_dark_mode_active (prefs.hex_gui_dark_mode);
 	if (context)

src/fe-gtk/theme/theme-preferences.c

@@ -106,6 +106,11 @@ typedef struct
         gboolean staged_dirty[THEME_TOKEN_COUNT];
         GdkRGBA snapshot[THEME_TOKEN_COUNT];
         GdkRGBA staged[THEME_TOKEN_COUNT];
+        /* the GTK3 theme selection is previewed live from the combo, so
+         * remember what was active when the dialog opened in order to
+         * restore it when the dialog is cancelled */
+        char gtk3_theme_snapshot[sizeof ((struct zoitechatprefs *) 0)->hex_gui_gtk3_theme];
+        int gtk3_variant_snapshot;
 } theme_preferences_stage_state;
 
 static theme_preferences_stage_state theme_preferences_stage;
@@ -204,6 +209,11 @@ theme_preferences_stage_begin (void)
         memset (&theme_preferences_stage, 0, sizeof (theme_preferences_stage));
         theme_preferences_stage.active = TRUE;
 
+        g_strlcpy (theme_preferences_stage.gtk3_theme_snapshot,
+                   prefs.hex_gui_gtk3_theme,
+                   sizeof (theme_preferences_stage.gtk3_theme_snapshot));
+        theme_preferences_stage.gtk3_variant_snapshot = prefs.hex_gui_gtk3_variant;
+
         for (token = THEME_TOKEN_MIRC_0; token < THEME_TOKEN_COUNT; token++)
         {
                 GdkRGBA rgba;
@@ -237,12 +247,36 @@ theme_preferences_stage_commit (void)
         memset (&theme_preferences_stage, 0, sizeof (theme_preferences_stage));
 }
 
+/* undo a live GTK3 theme preview: put the selection that was active when
+ * the dialog opened back and re-apply it */
+static void
+theme_preferences_stage_restore_gtk3 (void)
+{
+        if (g_strcmp0 (prefs.hex_gui_gtk3_theme, theme_preferences_stage.gtk3_theme_snapshot) == 0 &&
+            prefs.hex_gui_gtk3_variant == theme_preferences_stage.gtk3_variant_snapshot)
+                return;
+
+        g_strlcpy (prefs.hex_gui_gtk3_theme,
+                   theme_preferences_stage.gtk3_theme_snapshot,
+                   sizeof (prefs.hex_gui_gtk3_theme));
+        prefs.hex_gui_gtk3_variant = theme_preferences_stage.gtk3_variant_snapshot;
+
+        theme_gtk3_apply_current (NULL);
+        theme_manager_dispatch_changed (THEME_CHANGED_REASON_THEME_PACK |
+                                        THEME_CHANGED_REASON_PALETTE |
+                                        THEME_CHANGED_REASON_WIDGET_STYLE |
+                                        THEME_CHANGED_REASON_USERLIST |
+                                        THEME_CHANGED_REASON_MODE);
+}
+
 void
 theme_preferences_stage_discard (void)
 {
         if (!theme_preferences_stage.active)
                 return;
 
+        /* restore the GTK3 theme first so the color snapshot below wins */
+        theme_preferences_stage_restore_gtk3 ();
         theme_preferences_stage_sync_runtime_to_snapshot ();
         memset (&theme_preferences_stage, 0, sizeof (theme_preferences_stage));
 }
@@ -1567,7 +1601,6 @@ theme_preferences_gtk3_sync_runtime_palette (theme_preferences_ui *ui)
 {
 	ThemeWidgetStyleValues style_values;
 	GtkWidget *style_source = NULL;
-	gboolean follows_system_theme = prefs.hex_gui_gtk3_theme[0] == '\0';
 
 	if (ui && ui->parent)
 		style_source = GTK_WIDGET (ui->parent);
@@ -1578,34 +1611,16 @@ theme_preferences_gtk3_sync_runtime_palette (theme_preferences_ui *ui)
 
 	theme_get_widget_style_values_for_widget (style_source, &style_values);
 
-	if (follows_system_theme)
-	{
-		/* Following the system GTK3 theme: leave the mapped tokens
-		 * unpinned so they keep tracking the theme, and only refresh
-		 * what the dialog shows. */
-		theme_preferences_stage_rebase_color (THEME_TOKEN_TEXT_FOREGROUND, &style_values.foreground);
-		theme_preferences_stage_rebase_color (THEME_TOKEN_TEXT_BACKGROUND, &style_values.background);
-		theme_preferences_stage_rebase_color (THEME_TOKEN_SELECTION_FOREGROUND, &style_values.selection_foreground);
-		theme_preferences_stage_rebase_color (THEME_TOKEN_SELECTION_BACKGROUND, &style_values.selection_background);
-		return;
-	}
-
-	theme_preferences_staged_set_color (THEME_TOKEN_TEXT_FOREGROUND,
-	                                    &style_values.foreground,
-	                                    NULL,
-	                                    TRUE);
-	theme_preferences_staged_set_color (THEME_TOKEN_TEXT_BACKGROUND,
-	                                    &style_values.background,
-	                                    NULL,
-	                                    TRUE);
-	theme_preferences_staged_set_color (THEME_TOKEN_SELECTION_FOREGROUND,
-	                                    &style_values.selection_foreground,
-	                                    NULL,
-	                                    TRUE);
-	theme_preferences_staged_set_color (THEME_TOKEN_SELECTION_BACKGROUND,
-	                                    &style_values.selection_background,
-	                                    NULL,
-	                                    TRUE);
+	/* Leave the mapped tokens unpinned so the user list, channel tree and
+	 * input box keep resolving their colors from whatever GTK3 theme is
+	 * active (system or in-app selected), and only refresh what the
+	 * dialog shows.  Pinning theme-derived values here freezes them into
+	 * the runtime palette (and colors.conf), which left those widgets
+	 * with stale colors until the next restart. */
+	theme_preferences_stage_rebase_color (THEME_TOKEN_TEXT_FOREGROUND, &style_values.foreground);
+	theme_preferences_stage_rebase_color (THEME_TOKEN_TEXT_BACKGROUND, &style_values.background);
+	theme_preferences_stage_rebase_color (THEME_TOKEN_SELECTION_FOREGROUND, &style_values.selection_foreground);
+	theme_preferences_stage_rebase_color (THEME_TOKEN_SELECTION_BACKGROUND, &style_values.selection_background);
 }
 
 static gboolean

src/fe-gtk/userlistgui.c

@@ -796,16 +796,12 @@ userlist_store_color (GtkListStore *store, GtkTreeIter *iter, ThemeSemanticToken
 	}
 }
 
-GtkListStore *
-userlist_create_model (session *sess)
+static void
+userlist_model_set_sort (GtkListStore *store, session *sess)
 {
-	GtkListStore *store;
 	GtkTreeIterCompareFunc cmp_func;
 	GtkSortType sort_type;
 
-	store = gtk_list_store_new (6, GDK_TYPE_PIXBUF, G_TYPE_STRING, G_TYPE_STRING,
-										G_TYPE_STRING, G_TYPE_POINTER, THEME_GTK_COLOR_TYPE);
-
 	switch (prefs.hex_gui_ulist_sort)
 	{
 	case 0:
@@ -825,18 +821,77 @@ userlist_create_model (session *sess)
 		sort_type = GTK_SORT_DESCENDING;
 		break;
 	default:
-		/* No sorting */
+		/* No sorting; rows keep their current order and new rows
+		   go wherever they are inserted */
+		gtk_tree_sortable_set_sort_column_id (GTK_TREE_SORTABLE(store),
+							GTK_TREE_SORTABLE_UNSORTED_SORT_COLUMN_ID, GTK_SORT_ASCENDING);
 		gtk_tree_sortable_set_default_sort_func (GTK_TREE_SORTABLE(store), NULL, NULL, NULL);
-		return store;
+		return;
 	}
 
 	gtk_tree_sortable_set_default_sort_func (GTK_TREE_SORTABLE(store), cmp_func, sess, NULL);
 	gtk_tree_sortable_set_sort_column_id (GTK_TREE_SORTABLE(store),
 						GTK_TREE_SORTABLE_DEFAULT_SORT_COLUMN_ID, sort_type);
+}
+
+GtkListStore *
+userlist_create_model (session *sess)
+{
+	GtkListStore *store;
+
+	store = gtk_list_store_new (6, GDK_TYPE_PIXBUF, G_TYPE_STRING, G_TYPE_STRING,
+										G_TYPE_STRING, G_TYPE_POINTER, THEME_GTK_COLOR_TYPE);
+	userlist_model_set_sort (store, sess);
 
 	return store;
 }
 
+void
+userlist_apply_sort (session *sess)
+{
+	if (!sess->res || !sess->res->user_model)
+		return;
+
+	userlist_model_set_sort (sess->res->user_model, sess);
+}
+
+/* remove and re-insert every row, so per-row content that depends on
+ * preferences (mode icons vs. text prefixes, hostnames) is rebuilt */
+void
+userlist_refill (session *sess)
+{
+	GtkTreeModel *model;
+	GtkTreeIter iter;
+	GSList *users = NULL;
+	GSList *it;
+	struct User *user;
+
+	if (!sess->res || !sess->res->user_model)
+		return;
+
+	model = GTK_TREE_MODEL (sess->res->user_model);
+	if (gtk_tree_model_get_iter_first (model, &iter))
+	{
+		do
+		{
+			gtk_tree_model_get (model, &iter, COL_USER, &user, -1);
+			if (user)
+				users = g_slist_prepend (users, user);
+		}
+		while (gtk_tree_model_iter_next (model, &iter));
+	}
+
+	fe_userlist_clear (sess);
+
+	/* fe_userlist_insert() prepends, so inserting in reverse display
+	   order restores the on-screen order for unsorted lists; sorted
+	   models position the rows themselves */
+	for (it = users; it; it = it->next)
+		fe_userlist_insert (sess, it->data, FALSE);
+
+	g_slist_free (users);
+}
+
 static void
 userlist_add_columns (GtkTreeView * treeview)
 {
@@ -906,6 +961,23 @@ userlist_add_columns (GtkTreeView * treeview)
 	}
 }
 
+void
+userlist_rebuild_columns (GtkWidget *treeview)
+{
+	GList *columns;
+	GList *it;
+
+	if (!treeview)
+		return;
+
+	columns = gtk_tree_view_get_columns (GTK_TREE_VIEW (treeview));
+	for (it = columns; it; it = it->next)
+		gtk_tree_view_remove_column (GTK_TREE_VIEW (treeview), it->data);
+	g_list_free (columns);
+
+	userlist_add_columns (GTK_TREE_VIEW (treeview));
+}
+
 static gint
 userlist_click_cb (GtkWidget *widget, GdkEventButton *event, gpointer userdata)
 {

src/fe-gtk/userlistgui.h

@@ -24,6 +24,9 @@ void userlist_set_value (GtkWidget *treeview, gfloat val);
 gfloat userlist_get_value (GtkWidget *treeview);
 GtkWidget *userlist_create (GtkWidget *box);
 GtkListStore *userlist_create_model (session *sess);
+void userlist_apply_sort (session *sess);
+void userlist_refill (session *sess);
+void userlist_rebuild_columns (GtkWidget *treeview);
 void userlist_show (session *sess);
 void userlist_select (session *sess, char *name);
 void fe_userlist_set_typing (session *sess, const char *nick, const char *state);