Fix reporting of hardlink mismatch during compare

* src/common.h (quote_n_colon): New prototype.
* src/misc.c (quote_n_colon): New function.
* src/compare.c (report_difference, diff_link): Use quote_n_colon.

* tests/difflink.at: New file.
* tests/Makefile.am: Add difflink.at
* tests/testsuite.at: Likewise.

src/common.h

@@ -619,6 +619,8 @@ void skip_member (void);
 
 #define min(a, b) ((a) < (b) ? (a) : (b))
 #define max(a, b) ((a) < (b) ? (b) : (a))
+
+char const *quote_n_colon (int n, char const *arg);
 void assign_string (char **dest, const char *src);
 int unquote_string (char *str);
 char *zap_slashes (char *name);

src/compare.c

@@ -51,6 +51,8 @@ diff_init (void)
     read_directory_file ();
 }
 
+enum { QUOTE_ARG, QUOTE_NAME };
+
 /* Sigh about something that differs by writing a MESSAGE to stdlis,
    given MESSAGE is nonzero.  Also set the exit status if not already.  */
 void
@@ -60,7 +62,7 @@ report_difference (struct tar_stat_info *st, const char *fmt, ...)
     {
       va_list ap;
 
-      fprintf (stdlis, "%s: ", quotearg_colon (st->file_name));
+      fprintf (stdlis, "%s: ", quote_n_colon (QUOTE_NAME, st->file_name));
       va_start (ap, fmt);
       vfprintf (stdlis, fmt, ap);
       va_end (ap);
@@ -263,7 +265,8 @@ diff_link (void)
       && !sys_compare_links (&file_data, &link_data))
     report_difference (&current_stat_info,
 		       _("Not linked to %s"),
-		       quote (current_stat_info.link_name));
+		       quote_n_colon (QUOTE_ARG,
+				      current_stat_info.link_name));
 }
 
 #ifdef HAVE_READLINK

src/misc.c

@@ -33,6 +33,11 @@ static void namebuf_add_dir (namebuf_t, char const *);
 static char *namebuf_finish (namebuf_t);
 static const char *tar_getcdpath (int);
 
+char const *
+quote_n_colon (int n, char const *arg)
+{
+  return quotearg_n_style_colon (n, get_quoting_style (NULL), arg);
+}
 
 /* Handling strings.  */