From 739fc746bfbefb67fe46afda8bc4ed0994bc1e11 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Mon, 12 Feb 2024 19:30:04 -0800
Subject: [PATCH] terminal: OSC parses 4 with empty string param without
 crashing

---
 src/terminal/osc.zig | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/terminal/osc.zig b/src/terminal/osc.zig
index b55b8a199..a220ea031 100644
--- a/src/terminal/osc.zig
+++ b/src/terminal/osc.zig
@@ -445,8 +445,14 @@ pub const Parser = struct {
 
             .color_palette_index => switch (c) {
                 '0'...'9' => {},
-                ';' => {
-                    if (std.fmt.parseUnsigned(u8, self.buf[self.buf_start .. self.buf_idx - 1], 10)) |num| {
+                ';' => blk: {
+                    const str = self.buf[self.buf_start .. self.buf_idx - 1];
+                    if (str.len == 0) {
+                        self.state = .invalid;
+                        break :blk;
+                    }
+
+                    if (std.fmt.parseUnsigned(u8, str, 10)) |num| {
                         self.state = .color_palette_index_end;
                         self.temp_state = .{ .num = num };
                     } else |err| switch (err) {
@@ -1254,3 +1260,15 @@ test "OSC: show desktop notification with title" {
     try testing.expectEqualStrings(cmd.show_desktop_notification.title, "Title");
     try testing.expectEqualStrings(cmd.show_desktop_notification.body, "Body");
 }
+
+test "OSC: empty param" {
+    const testing = std.testing;
+
+    var p: Parser = .{};
+
+    const input = "4;;";
+    for (input) |ch| p.next(ch);
+
+    const cmd = p.end('\x1b');
+    try testing.expect(cmd == null);
+}