ls --color: don't emit a final no-op escape sequence

* src/ls.c (main): With --color, avoid emitting the final color-
resetting escape sequence when it would be a no-op.
* tests/ls/color-clear-to-eol: Adjust expected output accordingly.
* tests/ls/color-dtype-dir: Likewise.
* tests/ls/multihardlink: Likewise.
* tests/ls/stat-free-symlinks: Likewise.
* tests/misc/ls-misc: Likewise.
* NEWS (Changes in behavior): Mention it.
C de-Avillez rebased and adapted four of the new sl-dangle*
tests in tests/misc/ls-misc.
Reported by Jim Avera in
http://bugs.launchpad.net/ubuntu/+source/coreutils/+bug/494663

1 files changed, 9 insertions, 1 deletions

diff --git a/src/ls.c b/src/ls.c
index 9ef7eba21..680679a9a 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -1442,7 +1442,15 @@ main (int argc, char **argv)
       int j;
 
       if (used_color)
-        restore_default_color ();
+        {
+          /* Skip the restore when it would be a no-op, i.e.,
+             when left is "\033[" and right is "m".  */
+          if (!(color_indicator[C_LEFT].len == 2
+                && memcmp (color_indicator[C_LEFT].string, "\033[", 2) == 0
+                && color_indicator[C_RIGHT].len == 1
+                && color_indicator[C_RIGHT].string[0] == 'm'))
+            restore_default_color ();
+        }
       fflush (stdout);
 
       /* Restore the default signal handling.  */