From 1308a141389b80d11f3b6c54ecf43d2cb4e44503 Mon Sep 17 00:00:00 2001
From: CJ van den Berg <cj@vdbonline.com>
Date: Fri, 26 Dec 2025 16:50:38 +0100
Subject: [PATCH] fix: crash on cancelling the change theme palette

This commit also cleans up the handling of the previous theme variable.
---
 src/tui/mode/overlay/theme_palette.zig | 41 +++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/src/tui/mode/overlay/theme_palette.zig b/src/tui/mode/overlay/theme_palette.zig
index b0dbca3..a58e984 100644
--- a/src/tui/mode/overlay/theme_palette.zig
+++ b/src/tui/mode/overlay/theme_palette.zig
@@ -24,19 +24,22 @@ pub const Match = struct {
     matches: []const usize,
 };
 
-var previous_theme: ?[]const u8 = null;
+pub const ValueType = struct {
+    previous_theme: ?[]const u8 = null,
+};
+pub const defaultValue: ValueType = .{};
 
 pub fn load_entries(palette: *Type) !usize {
     var longest_hint: usize = 0;
     var idx: usize = 0;
-    previous_theme = tui.theme().name;
+    try set_previous_theme(palette, tui.theme().name);
     for (Widget.themes) |theme| {
         idx += 1;
         (try palette.entries.addOne(palette.allocator)).* = .{
             .label = theme.description,
             .name = theme.name,
         };
-        if (previous_theme) |theme_name| if (std.mem.eql(u8, theme.name, theme_name)) {
+        if (get_previous_theme(palette)) |theme_name| if (std.mem.eql(u8, theme.name, theme_name)) {
             palette.initial_selected = idx;
         };
         longest_hint = @max(longest_hint, theme.name.len);
@@ -45,6 +48,27 @@ pub fn load_entries(palette: *Type) !usize {
     return longest_hint;
 }
 
+pub fn deinit(palette: *Type) void {
+    clear_previous_theme(palette);
+}
+
+fn clear_previous_theme(palette: *Type) void {
+    tp.trace(tp.channel.debug, .{ "clear_previous_theme", palette.value.previous_theme });
+    if (palette.value.previous_theme) |old| palette.allocator.free(old);
+    palette.value.previous_theme = null;
+}
+
+fn set_previous_theme(palette: *Type, theme: []const u8) error{OutOfMemory}!void {
+    tp.trace(tp.channel.debug, .{ "set_previous_theme", palette.value.previous_theme, theme });
+    clear_previous_theme(palette);
+    palette.value.previous_theme = try palette.allocator.dupe(u8, theme);
+}
+
+fn get_previous_theme(palette: *Type) ?[]const u8 {
+    tp.trace(tp.channel.debug, .{ "get_previous_theme", palette.value.previous_theme });
+    return palette.value.previous_theme;
+}
+
 pub fn add_menu_entry(palette: *Type, entry: *Entry, matches: ?[]const usize) !void {
     var value: std.Io.Writer.Allocating = .init(palette.allocator);
     defer value.deinit();
@@ -57,15 +81,16 @@ pub fn add_menu_entry(palette: *Type, entry: *Entry, matches: ?[]const usize) !v
 }
 
 fn select(menu: **Type.MenuType, button: *Type.ButtonType, _: Type.Pos) void {
+    const palette = menu.*.opts.ctx;
     var description_: []const u8 = undefined;
     var name_: []const u8 = undefined;
     var iter = button.opts.label;
     if (!(cbor.matchString(&iter, &description_) catch false)) return;
     if (!(cbor.matchString(&iter, &name_) catch false)) return;
-    if (previous_theme) |prev| if (std.mem.eql(u8, prev, name_))
+    if (get_previous_theme(palette)) |prev| if (std.mem.eql(u8, prev, name_))
         return;
-    tp.self_pid().send(.{ "cmd", "set_theme", .{name_} }) catch |e| menu.*.opts.ctx.logger.err("theme_palette", e);
-    tp.self_pid().send(.{ "cmd", "exit_overlay_mode" }) catch |e| menu.*.opts.ctx.logger.err("theme_palette", e);
+    tp.self_pid().send(.{ "cmd", "set_theme", .{name_} }) catch |e| palette.logger.err("theme_palette", e);
+    tp.self_pid().send(.{ "cmd", "exit_overlay_mode" }) catch |e| palette.logger.err("theme_palette", e);
 }
 
 pub fn updated(palette: *Type, button_: ?*Type.ButtonType) !void {
@@ -79,8 +104,8 @@ pub fn updated(palette: *Type, button_: ?*Type.ButtonType) !void {
 }
 
 pub fn cancel(palette: *Type) !void {
-    if (previous_theme) |name_| if (!std.mem.eql(u8, name_, tui.theme().name)) {
-        previous_theme = null;
+    if (get_previous_theme(palette)) |name_| if (!std.mem.eql(u8, name_, tui.theme().name)) {
         tp.self_pid().send(.{ "cmd", "set_theme", .{name_} }) catch |e| palette.logger.err("theme_palette cancel", e);
+        clear_previous_theme(palette);
     };
 }