fix: gutters should only accept diff updates for their attached editor

src/diffz.zig

@@ -32,9 +32,9 @@ pub const AsyncDiffer = struct {
         return text.toOwnedSlice();
     }
 
-    pub const CallBack = fn (from: tp.pid_ref, edits: []Diff) void;
+    pub const CallBack = fn (from: tp.pid_ref, data: usize, edits: []Diff) void;
 
-    pub fn diff_buffer(self: @This(), cb: *const CallBack, buffer: *const Buffer) tp.result {
+    pub fn diff_buffer(self: @This(), cb: *const CallBack, cb_data: usize, buffer: *const Buffer) tp.result {
         const eol_mode = buffer.file_eol_mode;
         const text_dst = text_from_root(buffer.root, eol_mode) catch |e| return tp.exit_error(e, @errorReturnTrace());
         errdefer std.heap.c_allocator.free(text_dst);
@@ -45,7 +45,7 @@ pub const AsyncDiffer = struct {
         errdefer std.heap.c_allocator.free(text_src);
         const text_dst_ptr: usize = if (text_dst.len > 0) @intFromPtr(text_dst.ptr) else 0;
         const text_src_ptr: usize = if (text_src.len > 0) @intFromPtr(text_src.ptr) else 0;
-        if (self.pid) |pid| try pid.send(.{ "D", @intFromPtr(cb), text_dst_ptr, text_dst.len, text_src_ptr, text_src.len });
+        if (self.pid) |pid| try pid.send(.{ "D", @intFromPtr(cb), cb_data, text_dst_ptr, text_dst.len, text_src_ptr, text_src.len });
     }
 };
 
@@ -77,30 +77,34 @@ const Process = struct {
         errdefer self.deinit();
 
         var cb: usize = 0;
+        var cb_data: usize = 0;
         var text_dst_ptr: usize = 0;
         var text_dst_len: usize = 0;
         var text_src_ptr: usize = 0;
         var text_src_len: usize = 0;
 
-        return if (try m.match(.{ "D", tp.extract(&cb), tp.extract(&text_dst_ptr), tp.extract(&text_dst_len), tp.extract(&text_src_ptr), tp.extract(&text_src_len) })) blk: {
+        return if (try m.match(.{ "D", tp.extract(&cb), tp.extract(&cb_data), tp.extract(&text_dst_ptr), tp.extract(&text_dst_len), tp.extract(&text_src_ptr), tp.extract(&text_src_len) })) blk: {
             const text_dst = if (text_dst_len > 0) @as([*]const u8, @ptrFromInt(text_dst_ptr))[0..text_dst_len] else "";
             const text_src = if (text_src_len > 0) @as([*]const u8, @ptrFromInt(text_src_ptr))[0..text_src_len] else "";
-            break :blk do_diff_async(from, cb, text_dst, text_src) catch |e| tp.exit_error(e, @errorReturnTrace());
+            const cb_: *AsyncDiffer.CallBack = if (cb == 0) return else @ptrFromInt(cb);
+            break :blk do_diff_async(from, cb_, cb_data, text_dst, text_src) catch |e| {
+                cb_(from, cb_data, &.{});
+                break :blk tp.exit_error(e, @errorReturnTrace());
+            };
         } else if (try m.match(.{"shutdown"}))
             tp.exit_normal();
     }
 
-    fn do_diff_async(from_: tp.pid_ref, cb_addr: usize, text_dst: []const u8, text_src: []const u8) !void {
+    fn do_diff_async(from: tp.pid_ref, cb: *AsyncDiffer.CallBack, cb_data: usize, text_dst: []const u8, text_src: []const u8) !void {
         defer std.heap.c_allocator.free(text_dst);
         defer std.heap.c_allocator.free(text_src);
-        const cb_: *AsyncDiffer.CallBack = if (cb_addr == 0) return else @ptrFromInt(cb_addr);
 
         var arena_ = std.heap.ArenaAllocator.init(allocator);
         defer arena_.deinit();
         const arena = arena_.allocator();
 
         const edits = try diff(arena, text_dst, text_src);
-        cb_(from_, edits);
+        cb(from, cb_data, edits);
     }
 };
 

src/tui/editor_gutter.zig

@@ -368,18 +368,36 @@ fn diff_update(self: *Self, clear: bool) !void {
         self.diff_symbols_clear();
         return;
     }
-    return self.differ.diff_buffer(diff_result, self.editor.buffer orelse return);
+    const ctx = try self.allocator.create(DiffContext);
+    ctx.* = .{
+        .allocator = self.allocator,
+        .file_path = try self.allocator.dupe(u8, self.editor.file_path orelse ""),
+    };
+    return self.differ.diff_buffer(diff_result, @intFromPtr(ctx), self.editor.buffer orelse return);
 }
 
-fn diff_result(from: tp.pid_ref, edits: []Diff) void {
+const DiffContext = struct {
-    diff_result_send(from, edits) catch |e| @import("log").err(@typeName(Self), "diff", e);
+    allocator: std.mem.Allocator,
+    file_path: []u8,
+
+    fn deinit(self: *@This()) void {
+        self.allocator.free(self.file_path);
+        self.allocator.destroy(self);
+    }
+};
+
+fn diff_result(from: tp.pid_ref, data: usize, edits: []Diff) void {
+    const ctx: *DiffContext = @ptrFromInt(data);
+    defer ctx.deinit();
+    diff_result_send(from, ctx, edits) catch |e| @import("log").err(@typeName(Self), "diff", e);
 }
 
-fn diff_result_send(from: tp.pid_ref, edits: []Diff) !void {
+fn diff_result_send(from: tp.pid_ref, ctx: *DiffContext, edits: []Diff) !void {
     var buf: std.Io.Writer.Allocating = .init(std.heap.c_allocator);
     defer buf.deinit();
-    try cbor.writeArrayHeader(&buf.writer, 2);
+    try cbor.writeArrayHeader(&buf.writer, 3);
     try cbor.writeValue(&buf.writer, "DIFF");
+    try cbor.writeValue(&buf.writer, ctx.file_path);
     try cbor.writeArrayHeader(&buf.writer, edits.len);
     for (edits) |edit| {
         try cbor.writeArrayHeader(&buf.writer, 3);
@@ -421,11 +439,14 @@ fn process_edit(self: *Self, kind: Kind, line: usize, lines: usize) !void {
 }
 
 pub fn filter_receive(self: *Self, _: tp.pid_ref, m: tp.message) MessageFilter.Error!bool {
+    var file_path: []const u8 = undefined;
     var cb: []const u8 = undefined;
-    if (cbor.match(m.buf, .{ "DIFF", tp.extract_cbor(&cb) }) catch false) {
+    if (cbor.match(m.buf, .{ "DIFF", tp.extract(&file_path), tp.extract_cbor(&cb) }) catch false) {
+        if (std.mem.eql(u8, file_path, self.editor.file_path orelse return false)) {
             try self.process_diff(cb);
             return true;
         }
+    }
     return false;
 }