From a19aa0a398f2dcd0494482981f604d8113cd7f27 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Fri, 12 Sep 2025 21:08:52 -0700
Subject: [PATCH] terminal: OSC 104 with no semicolon should parse as reset
 palette

https://github.com/ghostty-org/ghostty/pull/8590#issuecomment-3287418867
---
 src/terminal/Parser.zig | 32 ++++++++++++++++++++++++++++++++
 src/terminal/osc.zig    | 16 +++++++++++++++-
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/src/terminal/Parser.zig b/src/terminal/Parser.zig
index 0c814ff68..1f2e814f6 100644
--- a/src/terminal/Parser.zig
+++ b/src/terminal/Parser.zig
@@ -930,6 +930,38 @@ test "osc: 112 incomplete sequence" {
     }
 }
 
+test "osc: 104 empty" {
+    var p: Parser = init();
+    defer p.deinit();
+    p.osc_parser.alloc = std.testing.allocator;
+
+    _ = p.next(0x1B);
+    _ = p.next(']');
+    _ = p.next('1');
+    _ = p.next('0');
+    _ = p.next('4');
+
+    {
+        const a = p.next(0x07);
+        try testing.expect(p.state == .ground);
+        try testing.expect(a[0].? == .osc_dispatch);
+        try testing.expect(a[1] == null);
+        try testing.expect(a[2] == null);
+
+        const cmd = a[0].?.osc_dispatch;
+        try testing.expect(cmd == .color_operation);
+        try testing.expectEqual(cmd.color_operation.terminator, .bel);
+        try testing.expect(cmd.color_operation.op == .osc_104);
+        try testing.expect(cmd.color_operation.requests.count() == 1);
+        var it = cmd.color_operation.requests.constIterator(0);
+        {
+            const op = it.next().?;
+            try testing.expect(op.* == .reset_palette);
+        }
+        try std.testing.expect(it.next() == null);
+    }
+}
+
 test "csi: too many params" {
     var p = init();
     _ = p.next(0x1B);
diff --git a/src/terminal/osc.zig b/src/terminal/osc.zig
index 72efc949e..028fcdf0a 100644
--- a/src/terminal/osc.zig
+++ b/src/terminal/osc.zig
@@ -557,7 +557,11 @@ pub const Parser = struct {
                     self.buf_start = self.buf_idx;
                     self.complete = true;
                 },
-                '4' => self.state = .@"104",
+                '4' => {
+                    self.state = .@"104";
+                    // If we have an allocator, then we can complete the OSC104
+                    if (self.alloc != null) self.complete = true;
+                },
                 else => self.state = .invalid,
             },
 
@@ -1584,6 +1588,16 @@ pub const Parser = struct {
             .kitty_color_protocol_value => self.endKittyColorProtocolOption(.key_and_value, true),
             .osc_color => self.endOscColor(),
 
+            // 104 abruptly ended turns into a reset palette command.
+            .@"104" => {
+                self.command = .{ .color_operation = .{
+                    .op = .osc_104,
+                } };
+                self.state = .osc_color;
+                self.buf_start = self.buf_idx;
+                self.endOscColor();
+            },
+
             // We received OSC 9;X ST, but nothing else, finish off as a
             // desktop notification with "X" as the body.
             .conemu_sleep,