addr reads empty after a failed address instead of failing

With no address after a failed write, a read of addr itself failed (EIO
through a mount), which reads as a broken file rather than as no address.
It now reads empty, as an unset limit does; data and xdata still refuse.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/docs/fs.md b/docs/fs.md
index c9d5356d..fc5a8586 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -563,9 +563,9 @@ expression`, `regular expression search gave up, ...`, or sam's
 `addresses out of order` for a range that ends before it starts
 (`#100,#50`), which acme lets through. A failed write to `addr` leaves no
 address at all, where acme
-keeps the old one: until a good address is written,
-reading `addr`, and reading, writing or truncating `data` and `xdata`, fail
-with `no address: the last one written to addr failed`, so a script that
+keeps the old one: until a good address is written, `addr` reads empty
+(as an unset `limit` does), and reading, writing or truncating `data` and
+`xdata` fail with `no address: the last one written to addr failed`, so a script that
 missed its target cannot then write at the last one.
 
 The three flag files `dirty`, `mark` and `scroll` read `0` or `1` and take