ls: use the POSIX date style when the locale does not specify one

Previously we defaulted to "long-iso" format in locales without
specific format translations, like the en_* locales for example.
This reverts part of commit 6837183d, 08-11-2005, "ls ... acts like
--time-style='posix-long-iso' if the locale settings are messed up"
* src/ls.c (decode_switches): Only use the ISO format when specified.
* NEWS: Mention the change in behavior.
Reported by Daniel Qarras at http://bugzilla.redhat.com/525134

4 files changed, 35 insertions, 15 deletions

diff --git a/NEWS b/NEWS
index 3e170c501..2bacb7f0e 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,15 @@ GNU coreutils NEWS                                    -*- outline -*-
 
 ** Changes in behavior
 
+  ls -l now uses the traditional three field time style rather than
+  the wider two field numeric ISO style, in locales where a style has
+  not been specified.  The new approach has nicer behavior in some
+  locales, including English, which was judged to outweigh the disadvantage
+  of generating less-predictable and often worse output in poorly-configured
+  locales where there is an onus to specify appropriate non-default styles.
+  [The old behavior was introduced in coreutils-6.0 and had been removed
+   for English only using a different method since coreutils-8.1]
+
   sort -g now uses long doubles for greater range and precision.
 
   stat no longer accepts the --context (-Z) option.  Initially it was
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index f103bd869..5c2bd1a84 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -6927,11 +6927,10 @@ is 80.
 @node Formatting file timestamps
 @subsection Formatting file timestamps
 
-By default, file timestamps are listed in abbreviated form.  Most
-locales use a timestamp like @samp{2002-03-30 23:45}.  However, the
-default @acronym{POSIX} locale uses a date like @samp{Mar 30@ @ 2002}
-for non-recent timestamps, and a date-without-year and time like
-@samp{Mar 30 23:45} for recent timestamps.
+By default, file timestamps are listed in abbreviated form, using
+a date like @samp{Mar 30@ @ 2002} for non-recent timestamps, and a
+date-without-year and time like @samp{Mar 30 23:45} for recent timestamps.
+This format can change depending on the current locale as detailed below.
 
 A timestamp is considered to be @dfn{recent} if it is less than six
 months old, and is not dated in the future.  If a timestamp dated
diff --git a/src/ls.c b/src/ls.c
index ff0ad2144..6e3e836cb 100644
--- a/src/ls.c
+++ b/src/ls.c
@@ -2032,7 +2032,6 @@ decode_switches (int argc, char **argv)
             break;
 
           case long_iso_time_style:
-          case_long_iso_time_style:
             long_time_format[0] = long_time_format[1] = "%Y-%m-%d %H:%M";
             break;
 
@@ -2044,17 +2043,10 @@ decode_switches (int argc, char **argv)
           case locale_time_style:
             if (hard_locale (LC_TIME))
               {
-                /* Ensure that the locale has translations for both
-                   formats.  If not, fall back on long-iso format.  */
                 int i;
                 for (i = 0; i < 2; i++)
-                  {
-                    char const *locale_format =
-                      dcgettext (NULL, long_time_format[i], LC_TIME);
-                    if (locale_format == long_time_format[i])
-                      goto case_long_iso_time_style;
-                    long_time_format[i] = locale_format;
-                  }
+                  long_time_format[i] =
+                    dcgettext (NULL, long_time_format[i], LC_TIME);
               }
           }
       /* Note we leave %5b etc. alone so user widths/flags are honored.  */
diff --git a/tests/misc/ls-time b/tests/misc/ls-time
index 1d10abb38..beea159c2 100755
--- a/tests/misc/ls-time
+++ b/tests/misc/ls-time
@@ -122,4 +122,24 @@ EOF
   fail=1
 fi
 
+# This check is ineffective if:
+#   en_US locale is not on the system.
+#   The system en_US message catalog has a specific TIME_FMT translation,
+#   which was inadvertently the case between coreutils 8.1 and 8.5 inclusive.
+
+if gettext --version >/dev/null 2>&1; then
+
+  default_tf1='%b %e  %Y'
+  en_tf1=$(LC_ALL=en_US gettext coreutils "$default_tf1")
+
+  if test "$default_tf1" = "$en_tf1"; then
+    LC_ALL=en_US ls -l c >en_output
+    ls -l --time-style=long-iso c >liso_output
+    if compare en_output liso_output; then
+      fail=1
+      echo "Long ISO TIME_FMT being used for en_US locale." >&2
+    fi
+  fi
+fi
+
 Exit $fail