1 files changed, 24 insertions, 0 deletions
diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index 2b366de0..89c2e5dd 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -4333,3 +4333,27 @@ test "a look of ./x that is not there is a miss, as x and /abs/x are: answered,
     }
     try testing.expect(th.logHas(p, "look: ./zzq-nosuch.txt: no such file"));
 }
+
+test "a ctl line over 1 MiB is refused once, EINVAL, and its tail is not run as a line of its own" {
+    const p = try withFile(testing.allocator, "x\n");
+    defer p.deinit();
+    const node = Node.of(serialOf(p), .ctl);
+    const h = call(p, .{ .tag = 1, .op = .open, .node = node, .omode = 1 }).reply.handle;
+    const chunk: [4096]u8 = @splat('z');
+    var refused: usize = 0;
+    var off: u64 = 0;
+    for (0..270) |_| {
+        const r = call(p, .{ .tag = 2, .op = .write, .node = node, .handle = h, .off = off, .data = &chunk });
+        if (r.reply.status == .err) {
+            refused += 1;
+            try testing.expectEqual(E.INVAL, r.errno());
+        }
+        off += chunk.len;
+    }
+    try testing.expectEqual(Status.ok, call(p, .{ .tag = 3, .op = .write, .node = node, .handle = h, .off = off, .data = "zzz\nEdit ,d\n" }).reply.status);
+    try testing.expectEqual(@as(usize, 1), refused);
+    try testing.expect(!th.logHas(p, "unknown control message"));
+    // What came after the long line's newline ran.
+    try testing.expectEqualStrings("", pane_files.fileOf(p.panes[0].?).?.content);
+    _ = call(p, .{ .tag = 4, .op = .release, .node = node, .handle = h });
+}