A Save the host cannot do fails the 9P write that asked for it, and the log names the path and why

The write answered ok and the pane stayed dirty, with `save: AccessDenied` on its message row: a script saw success. The failure now says `Save <path>: <why>`, and a 9P write that waited on the save fails with EIO and that text, logged as an err record.

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

1 files changed, 5 insertions, 0 deletions

diff --git a/src/fs.zig b/src/fs.zig
index b2e2751d..2dc3394b 100644
--- a/src/fs.zig
+++ b/src/fs.zig
@@ -1263,6 +1263,11 @@ pub const Namespace = struct {
     refused: bool = false,
     failure: [256]u8 = undefined,
     failure_len: u16 = 0,
+    /// What went wrong performing a write's effects after it was answered
+    /// by the core (a save the host could not do): the 9P write, which
+    /// waits for them, fails with it (src/9p_io.zig).
+    late_failure: [256]u8 = undefined,
+    late_failure_len: u16 = 0,
     /// A refusal that quotes the message it refuses, as Plan 9's cmderror
     /// does (kernel/misc/parse.c:82); answered at once (src/9p_io.zig).
     ename: [320]u8 = undefined,