From e549af76fe6e91305b86f1adc098566de6b4a2a7 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Wed, 26 Nov 2025 08:36:29 -0800
Subject: [PATCH] terminal: flattened highlights contain serial numbers for
 nodes

---
 src/terminal/highlight.zig             | 21 +++++++++++++++++----
 src/terminal/search/sliding_window.zig |  6 ++++++
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/terminal/highlight.zig b/src/terminal/highlight.zig
index 13c00b48e..4db5e31e7 100644
--- a/src/terminal/highlight.zig
+++ b/src/terminal/highlight.zig
@@ -114,7 +114,7 @@ pub const Flattened = struct {
     /// The page chunks that make up this highlight. This handles the
     /// y bounds since chunks[0].start is the first highlighted row
     /// and chunks[len - 1].end is the last highlighted row (exclsive).
-    chunks: std.MultiArrayList(PageChunk),
+    chunks: std.MultiArrayList(Chunk),
 
     /// The x bounds of the highlight. `bot_x` may be less than `top_x`
     /// for typical left-to-right highlights: can start the selection right
@@ -122,8 +122,16 @@ pub const Flattened = struct {
     top_x: size.CellCountInt,
     bot_x: size.CellCountInt,
 
-    /// Exposed for easier type references.
-    pub const Chunk = PageChunk;
+    /// A flattened chunk is almost identical to a PageList.Chunk but
+    /// we also flatten the serial number. This lets the flattened
+    /// highlight more robust for comparisons and validity checks with
+    /// the PageList.
+    pub const Chunk = struct {
+        node: *PageList.List.Node,
+        serial: u64,
+        start: size.CellCountInt,
+        end: size.CellCountInt,
+    };
 
     pub const empty: Flattened = .{
         .chunks = .empty,
@@ -139,7 +147,12 @@ pub const Flattened = struct {
         var result: std.MultiArrayList(PageChunk) = .empty;
         errdefer result.deinit(alloc);
         var it = start.pageIterator(.right_down, end);
-        while (it.next()) |chunk| try result.append(alloc, chunk);
+        while (it.next()) |chunk| try result.append(alloc, .{
+            .node = chunk.node,
+            .serial = chunk.node.serial,
+            .start = chunk.start,
+            .end = chunk.end,
+        });
         return .{
             .chunks = result,
             .top_x = start.x,
diff --git a/src/terminal/search/sliding_window.zig b/src/terminal/search/sliding_window.zig
index ff0fa0277..66f7bc70c 100644
--- a/src/terminal/search/sliding_window.zig
+++ b/src/terminal/search/sliding_window.zig
@@ -87,6 +87,7 @@ pub const SlidingWindow = struct {
     const MetaBuf = CircBuf(Meta, undefined);
     const Meta = struct {
         node: *PageList.List.Node,
+        serial: u64,
         cell_map: std.ArrayList(point.Coordinate),
 
         pub fn deinit(self: *Meta, alloc: Allocator) void {
@@ -345,6 +346,7 @@ pub const SlidingWindow = struct {
                     result.bot_x = end_map.x;
                     self.chunk_buf.appendAssumeCapacity(.{
                         .node = meta.node,
+                        .serial = meta.serial,
                         .start = @intCast(start_map.y),
                         .end = @intCast(end_map.y + 1),
                     });
@@ -363,6 +365,7 @@ pub const SlidingWindow = struct {
                     result.top_x = map.x;
                     self.chunk_buf.appendAssumeCapacity(.{
                         .node = meta.node,
+                        .serial = meta.serial,
                         .start = @intCast(map.y),
                         .end = meta.node.data.size.rows,
                     });
@@ -397,6 +400,7 @@ pub const SlidingWindow = struct {
                     // to our results because we want the full flattened list.
                     self.chunk_buf.appendAssumeCapacity(.{
                         .node = meta.node,
+                        .serial = meta.serial,
                         .start = 0,
                         .end = meta.node.data.size.rows,
                     });
@@ -410,6 +414,7 @@ pub const SlidingWindow = struct {
                 result.bot_x = map.x;
                 self.chunk_buf.appendAssumeCapacity(.{
                     .node = meta.node,
+                    .serial = meta.serial,
                     .start = 0,
                     .end = @intCast(map.y + 1),
                 });
@@ -513,6 +518,7 @@ pub const SlidingWindow = struct {
         // Initialize our metadata for the node.
         var meta: Meta = .{
             .node = node,
+            .serial = node.serial,
             .cell_map = .empty,
         };
         errdefer meta.deinit(self.alloc);