A tag write over the limit is refused "no space: over 4096 bytes", so its err record says tag: once

The refusal's text began with "tag: ", and the log's err record puts the
file's name before the reason. So the record read `err - col/1/tag: tag:
no space: over 4096 bytes`. The text is now the reason alone, as the
control-character refusal's is, and the record names the file once.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 4 insertions, 1 deletions

diff --git a/src/ninep/cols.zig b/src/ninep/cols.zig
index 24fb590c..9185a2bc 100644
--- a/src/ninep/cols.zig
+++ b/src/ninep/cols.zig
@@ -500,7 +500,10 @@ test "a refused write after a truncation leaves every kind of tag as it was, and
         const h = th.call(p, .{ .tag = 2, .op = .open, .node = node, .omode = 1 }).reply.handle;
         const r = th.call(p, .{ .tag = 3, .op = .write, .node = node, .handle = h, .data = big });
         try testing.expectEqual(E.NOSPC, r.errno());
-        try testing.expectEqualStrings("tag: no space: over 4096 bytes", r.reply.ename);
+        try testing.expectEqualStrings("no space: over 4096 bytes", r.reply.ename);
+        // Its err record names the file once: `tag: no space`, never `tag: tag:`.
+        try testing.expect(th.logHas(p, "tag: no space: over 4096 bytes"));
+        try testing.expect(!th.logHas(p, "tag: tag:"));
         _ = th.call(p, .{ .tag = 4, .op = .release, .node = node, .handle = h, .opened = true });
         try testing.expectEqualStrings(before, th.rd(p, node, 0, 1 << 16).bytes);
         // A control character is refused the same way on every kind.