Address review comments

src/config/Config.zig

@@ -4186,18 +4186,25 @@ pub const SinglePath = struct {
     const Self = @This();
 
     /// The actual value that is updated as we parse.
-    value: []const u8 = "",
+    value: ?[]const u8 = null,
 
     /// Parse a single path.
     pub fn parseCLI(self: *Self, alloc: Allocator, input: ?[]const u8) !void {
         const value = input orelse return error.ValueRequired;
+        // If the value is empty, we set the value to null
+        if (value.len == 0) {
+            self.value = null;
+            return;
+        }
         const copy = try alloc.dupe(u8, value);
         self.value = copy;
     }
 
     /// Deep copy of the struct. Required by Config.
     pub fn clone(self: Self, alloc: Allocator) Allocator.Error!Self {
-        const copy_path = try alloc.dupe(u8, self.value);
+        const value = self.value orelse return .{};
+
+        const copy_path = try alloc.dupe(u8, value);
         return .{
             .value = copy_path,
         };
@@ -4205,7 +4212,8 @@ pub const SinglePath = struct {
 
     /// Used by Formatter
     pub fn formatEntry(self: Self, formatter: anytype) !void {
-        try formatter.formatEntry([]const u8, self.value);
+        const value = self.value orelse return;
+        try formatter.formatEntry([]const u8, value);
     }
 
     pub fn expand(
@@ -4218,10 +4226,9 @@ pub const SinglePath = struct {
         var dir = try std.fs.cwd().openDir(base, .{});
         defer dir.close();
 
-        const path = self.value;
-
         // If it is already absolute we can ignore it.
-        if (path.len == 0 or std.fs.path.isAbsolute(path)) return;
+        const path = self.value orelse return;
+        if (std.fs.path.isAbsolute(path)) return;
 
         // If it isn't absolute, we need to make it absolute relative
         // to the base.
@@ -4245,7 +4252,7 @@ pub const SinglePath = struct {
             });
 
             // Blank this path so that we don't attempt to resolve it again
-            self.value = "";
+            self.value = null;
 
             return;
         };

src/renderer/OpenGL.zig

@@ -828,7 +828,7 @@ pub fn updateFrame(
         }
 
         if (self.current_background_image == null and
-            self.background_image.value.len > 0)
+            self.background_image.value != null)
         {
             if (single_threaded_draw) self.draw_mutex.lock();
             defer if (single_threaded_draw) self.draw_mutex.unlock();
@@ -1208,8 +1208,7 @@ fn prepKittyImage(
 /// Prepares the current background image for upload
 pub fn prepBackgroundImage(self: *OpenGL) !void {
     // If the user doesn't have a background image, do nothing...
-    if (self.background_image.value.len == 0) return;
-    const path = self.background_image.value;
+    const path = self.background_image.value orelse return;
 
     // Read the file content
     const file_content = try self.readImageContent(path);
@@ -1234,8 +1233,9 @@ pub fn prepBackgroundImage(self: *OpenGL) !void {
 
 /// Reads the content of the given image path and returns it
 pub fn readImageContent(self: *OpenGL, path: []const u8) ![]u8 {
+    assert(std.fs.path.isAbsolute(path));
     // Open the file
-    var file = std.fs.cwd().openFile(path, .{}) catch |err| {
+    var file = std.fs.openFileAbsolute(path, .{}) catch |err| {
         log.warn("failed to open file: {}", .{err});
         return error.InvalidData;
     };
@@ -1258,13 +1258,12 @@ pub fn readImageContent(self: *OpenGL, path: []const u8) ![]u8 {
     // Read the file
     var managed = std.ArrayList(u8).init(self.alloc);
     errdefer managed.deinit();
-    const size: usize = max_image_size;
-    reader.readAllArrayList(&managed, size) catch |err| {
+    reader.readAllArrayList(&managed, max_image_size) catch |err| {
         log.warn("failed to read file: {}", .{err});
         return error.InvalidData;
     };
 
-    return managed.items;
+    return managed.toOwnedSlice();
 }
 
 /// rebuildCells rebuilds all the GPU cells from our CPU state. This is a