>From 7e244891b0c41bbf9f5b5917d1a71c183a8367ac Mon Sep 17 00:00:00 2001
From: Paul Eggert <address@hidden>
Date: Thu, 4 Jan 2018 13:57:40 -0800
Subject: [PATCH 1/2] mv: -n overrides -u

* NEWS: Mention these fixes.
* doc/coreutils.texi (cp invocation, mv invocation):
Mention that -n is silent, and that it overrides -u.
* src/cp.c, src/mv.c (main): -n overrides -u.
---
 NEWS               |  7 +++++++
 doc/coreutils.texi | 13 +++++++++----
 src/cp.c           |  3 +++
 src/mv.c           |  3 +++
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/NEWS b/NEWS
index b89254f7e..4712f5a46 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,13 @@ GNU coreutils NEWS                                    -*- outline -*-
 
 * Noteworthy changes in release ?.? (????-??-??) [?]
 
+** Bug fixes
+
+  'cp -n -u' and 'mv -n -u' now consistently ignore the -u option.
+  Previously, this option combination suffered from race conditions
+  that caused -u to sometimes override -n.
+  [bug introduced with coreutils-7.1]
+
 
 * Noteworthy changes in release 8.29 (2017-12-27) [stable]
 
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 1c0e8a36c..6bb9f0906 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -8569,7 +8569,8 @@ a regular file in the destination tree.
 @itemx --no-clobber
 @opindex -n
 @opindex --no-clobber
-Do not overwrite an existing file.  The @option{-n} option overrides a previous
+Do not overwrite an existing file; silently do nothing instead.
+This option overrides a previous
 @option{-i} option.  This option is mutually exclusive with @option{-b} or
 @option{--backup} option.
 
@@ -8809,8 +8810,10 @@ the comparison is to the source timestamp truncated to the
 resolutions of the destination file system and of the system calls
 used to update timestamps; this avoids duplicate work if several
 @samp{cp -pu} commands are executed with the same source and destination.
-If @option{--preserve=links} is also specified (like with @samp{cp -au}
-for example), that will take precedence.  Consequently, depending on the
+This option is ignored if the @option{-n} or @option{--no-clobber}
+option is also specified.
+Also, if @option{--preserve=links} is also specified (like with @samp{cp -au}
+for example), that will take precedence; consequently, depending on the
 order that files are processed from the source, newer files in the destination
 may be replaced, to mirror hard links in the source.
 
@@ -9657,7 +9660,7 @@ If the response is not affirmative, the file is skipped.
 @opindex -n
 @opindex --no-clobber
 @cindex prompts, omitting
-Do not overwrite an existing file.
+Do not overwrite an existing file; silently do nothing instead.
 @mvOptsIfn
 This option is mutually exclusive with @option{-b} or @option{--backup} option.
 
@@ -9673,6 +9676,8 @@ source timestamp truncated to the resolutions of the destination file
 system and of the system calls used to update timestamps; this avoids
 duplicate work if several @samp{mv -u} commands are executed with the
 same source and destination.
+This option is ignored if the @option{-n} or @option{--no-clobber}
+option is also specified.
 
 @item -v
 @itemx --verbose
diff --git a/src/cp.c b/src/cp.c
index 1b5bf7285..d81d41859 100644
--- a/src/cp.c
+++ b/src/cp.c
@@ -1145,6 +1145,9 @@ main (int argc, char **argv)
       usage (EXIT_FAILURE);
     }
 
+  if (x.interactive == I_ALWAYS_NO)
+    x.update = false;
+
   if (make_backups && x.interactive == I_ALWAYS_NO)
     {
       error (0, 0,
diff --git a/src/mv.c b/src/mv.c
index a8df730a7..818ca59b6 100644
--- a/src/mv.c
+++ b/src/mv.c
@@ -459,6 +459,9 @@ main (int argc, char **argv)
              quoteaf (file[n_files - 1]));
     }
 
+  if (x.interactive == I_ALWAYS_NO)
+    x.update = false;
+
   if (make_backups && x.interactive == I_ALWAYS_NO)
     {
       error (0, 0,
-- 
2.14.3