2 files changed, 33 insertions, 2 deletions
diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index 40ffebc8..16fbabb4 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -4379,3 +4379,33 @@ test "a Mount dial with a network it does not know is a bad dial address, EINVAL
     try testing.expectEqual(E.INVAL, r.errno());
     try testing.expectStringStartsWith(r.reply.ename, "Mount: bad dial address: nowhere!x");
 }
+
+test "a command or a terminal refused for room is refused before anything is logged of it, and its serial is never handed out again" {
+    const p = try withFile(testing.allocator, "x\n");
+    defer p.deinit();
+    const exec = Node.of(serialOf(p), .exec);
+    var buf: [32]u8 = undefined;
+    for ([_][]const u8{ "ls\n", "Tty\n" }) |line| {
+        // Each a pane of its own until the column has no room for one more.
+        var before = p.next_serial;
+        var tries: usize = 0;
+        while (tries < pardes.MAX_PANES) : (tries += 1) {
+            before = p.next_serial;
+            const r = wr(p, exec, line);
+            p.sync();
+            if (r.reply.status == .err) break;
+        } else return error.NeverRefused;
+        // Nothing said of the refused one: no new, no run, no del.
+        for (before + 1..p.next_serial + 1) |n| {
+            try testing.expect(!th.logHas(p, try std.fmt.bufPrint(&buf, "new {d} ", .{n})));
+            try testing.expect(!th.logHas(p, try std.fmt.bufPrint(&buf, "run {d} ", .{n})));
+            try testing.expect(!th.logHas(p, try std.fmt.bufPrint(&buf, "del {d} ", .{n})));
+        }
+        // And the next pane made takes a serial past it.
+        const spent = p.next_serial;
+        p.update(.{ .resize = .{ .cols = 200, .rows = 200 } });
+        const made = try th.newPane(p);
+        try testing.expect(made > spent);
+        p.update(.{ .resize = .{ .cols = 80, .rows = 24 } });
+    }
+}
diff --git a/src/ninep/tree.zig b/src/ninep/tree.zig
index e6c139c1..40543ecf 100644
--- a/src/ninep/tree.zig
+++ b/src/ninep/tree.zig
@@ -1905,10 +1905,11 @@ test "no placement leaves a pane shorter than its tag and two rows; a full colum
     } else return error.NeverRefused;
     try testing.expectEqual(E.NOSPC, refused.errno());
     try testing.expect(std.mem.indexOf(u8, refused.reply.ename, "no space for a pane in that column") != null);
-    // The refused pane was never there: no serial spent on it.
+    // The refused pane was never there; its serial is not handed out again
+    // (gaps are fine: a serial once said names one pane for good).
     const before = p.next_serial;
     try testing.expectEqual(E.NOSPC, call(p, .{ .tag = 1, .op = .open, .node = new }).errno());
-    try testing.expectEqual(before, p.next_serial);
+    try testing.expectEqual(before + 1, p.next_serial);
     p.sync();
     var count: usize = 0;
     for (p.panes) |slot| count += @intFromBool(slot != null);