doc: retroactively adjust info about tail and closed output

* NEWS: Expand on the 8.28 description of how tail more
responsively reacts to closed output, and move from "Improvements"
to "Changed behavior".
* cfg.mk (old_NEWS_hash): Regenerate.
Fixes https://bugs.gnu.org/31225

diff --git a/NEWS b/NEWS
index cf5dcaf4be943735b80a2d957ff3e9c2cc50614a..de028141b7aff65207715c2c4c95c78dd2e832a2 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -190,6 +190,13 @@ GNU coreutils NEWS                                    -*- outline -*-
 
   expr supports multibyte strings for all string operations.
 
+** Changes in behavior
+
+  tail -f now exits immediately if the output is piped and the reader of
+  the pipe terminates.  That allows `tail -f file | grep -q foo` to return
+  responsively, but does make `tail -f file | :` exit immediately without
+  waiting for data.  Instead one should now `tail -f file | grep -q .`
+
 ** Improvements
 
   mv --verbose now distinguishes rename and copy operations.
@@ -197,9 +204,6 @@ GNU coreutils NEWS                                    -*- outline -*-
   stat -f -c %l, used to output the max file name length on a file system,
   is now supported on FreeBSD and OpenBSD.
 
-  tail -f now exits immediately if the output is piped
-  and the reader of the pipe terminates.
-
   tail -f no longer erroneously warns about being ineffective
   when following a single tty, as the simple blocking loop used
   is effective in this case.

diff --git a/cfg.mk b/cfg.mk
index b13300ddb57946025f2e8462d99f27296fdfdffb..875fbaadd97603911c379e790c78a094654f2a9b 100644 (file)
--- a/cfg.mk
+++ b/cfg.mk
@@ -48,7 +48,7 @@ export VERBOSE = yes
 # 4914152 9e
 export XZ_OPT = -8e
 
-old_NEWS_hash = 0fa4f447093a392524d6f749c8d1fc82
+old_NEWS_hash = 48668bce5e01bf434b1d1ff10d141884
 
 # Add an exemption for sc_makefile_at_at_check.
 _makefile_at_at_check_exceptions = ' && !/^cu_install_prog/ && !/dynamic-dep/'