fix drag-select release crash: the 64-slot effect ring overflowed when one update emitted a big selection exec (emitWrite 64-byte chunks + padOutputBelowEdits CRs) and the emit assert panicked. Effects queue is now a growable ArrayList FIFO (payloads stay inline values); guard the two other Buf(256) asserts reachable from look (spawn cwd >256 -> error.PathTooLong in newShell, >256-char url skipped). New snap exec-bigdrag: giant middle-drag exec on a 60x200 grid, panicked before, alive-marker golden after.

1 files changed, 14 insertions, 8 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index c4893b25..d617e552 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -628,9 +628,11 @@ pub const Pardes = struct {
     /// press during an active middle select-drag; consumed on middle release
     chord_arg: ?[]u8 = null,
 
-    effects: [64]Effect = undefined,
+    /// pending effects, drained by the shell after each update. Growable: one
+    /// update can emit unbounded writes (a big selection executed is chunked
+    /// into 64-byte write effects) — a fixed ring overflows and panics.
+    effects: std.ArrayList(Effect) = .empty,
     effects_head: usize = 0,
-    effects_tail: usize = 0,
 
     /// modal yank register (gpa-owned); a yank also mirrors out to the system
     /// clipboard via the set_clipboard effect.
@@ -678,6 +680,7 @@ pub const Pardes = struct {
         if (p.yank) |y| gpa.free(y);
         if (p.dump_out) |d| gpa.free(d);
         if (p.chord_arg) |a| gpa.free(a);
+        p.effects.deinit(gpa);
         p.scratch.deinit();
         gpa.free(p.surface.cells);
         gpa.destroy(p);
@@ -717,6 +720,7 @@ pub const Pardes = struct {
 
     fn newShell(p: *Pardes, id: usize, cwd: []const u8) !*Pane {
         std.debug.assert(p.panes[id] == null);
+        if (cwd.len > 256) return error.PathTooLong; // spawn effect cwd is a Buf(256)
         const pane = try p.gpa.create(Pane);
         pane.* = .{
             .vt = try ghostty_vt.Terminal.init(p.gpa, .{
@@ -780,14 +784,16 @@ pub const Pardes = struct {
     }
 
     fn emit(p: *Pardes, e: Effect) void {
-        std.debug.assert(p.effects_tail - p.effects_head < p.effects.len);
-        p.effects[p.effects_tail % p.effects.len] = e;
-        p.effects_tail += 1;
+        p.effects.append(p.gpa, e) catch {};
     }
 
     pub fn nextEffect(p: *Pardes) ?Effect {
-        if (p.effects_head == p.effects_tail) return null;
-        const e = p.effects[p.effects_head % p.effects.len];
+        if (p.effects_head == p.effects.items.len) {
+            p.effects.clearRetainingCapacity();
+            p.effects_head = 0;
+            return null;
+        }
+        const e = p.effects.items[p.effects_head];
         p.effects_head += 1;
         return e;
     }
@@ -2607,7 +2613,7 @@ pub const Pardes = struct {
             };
             switch (look.resolve(txt, cwd, &realbuf)) {
                 .none => {},
-                .url => |u| p.emit(.{ .open_link = .from(u) }),
+                .url => |u| if (u.len <= 256) p.emit(.{ .open_link = .from(u) }),
                 .dir => |dir| {
                     // focus an existing terminal on this dir, else fork one below
                     for (p.panes, 0..) |slot, i| {