Improve error diagnostics

* src/names.c (file_list_name): New static function.
(add_file_id): If a filelist is being read twice, print the names
of the files that caused it.
* tests/T-rec.at: New test case.
* tests/Makefile.am: Add new file.
* tests/testsuite.at: Include new file.

src/names.c

@@ -340,29 +340,51 @@ struct file_id_list
   struct file_id_list *next;
   ino_t ino;
   dev_t dev;
+  const char *from_file;
 };
 
 static struct file_id_list *file_id_list;
 
+/* Return the name of the file from which the file names and options
+   are being read.
+*/
+static const char *
+file_list_name ()
+{
+  struct name_elt *elt;
+
+  for (elt = name_head; elt; elt = elt->next)
+    if (elt->type == NELT_FILE && elt->v.file.fp)
+      return elt->v.file.name;
+  return _("command line");
+}
+
 static int
 add_file_id (const char *filename)
 {
   struct file_id_list *p;
   struct stat st;
+  const char *reading_from;
 
   if (stat (filename, &st))
     stat_fatal (filename);
+  reading_from = file_list_name ();
   for (p = file_id_list; p; p = p->next)
     if (p->ino == st.st_ino && p->dev == st.st_dev)
       {
-	ERROR ((0, 0, _("%s: file list already read"),
-		quotearg_colon (filename)));
+	int oldc = set_char_quoting (NULL, ':', 1);
+	ERROR ((0, 0,
+		_("%s: file list requested from %s already read from %s"),
+		quotearg_n (0, filename),
+		reading_from, p->from_file));
+	set_char_quoting (NULL, ':', oldc);
 	return 1;
       }
   p = xmalloc (sizeof *p);
   p->next = file_id_list;
   p->ino = st.st_ino;
   p->dev = st.st_dev;
+  p->from_file = reading_from;
   file_id_list = p;
   return 0;
 }

tests/Makefile.am

@@ -45,6 +45,7 @@ TESTSUITE_AT = \
  T-cd.at\
  T-empty.at\
  T-null.at\
+ T-rec.at\
  T-zfile.at\
  T-nonl.at\
  T-mult.at\

tests/T-rec.at

@@ -0,0 +1,46 @@
+# Process this file with autom4te to create testsuite. -*- Autotest -*-
+#
+# Test suite for GNU tar.
+# Copyright 2013 Free Software Foundation, Inc.
+#
+# This file is part of GNU tar.
+#
+# GNU tar is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# GNU tar is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([recursive file lists])
+AT_KEYWORDS([files-from T-rec])
+
+AT_TAR_CHECK([
+>file1
+>file2
+AT_DATA([F1],[file1
+-T F2
+])
+AT_DATA([F2],[file2
+-T F1
+])
+tar cf archive -T F1
+echo $?
+tar tf archive
+],
+[0],
+[2
+file1
+file2
+],
+[tar: F1: file list requested from F2 already read from command line
+tar: Exiting with failure status due to previous errors
+],[],[],[ustar])
+
+AT_CLEANUP

tests/testsuite.at

@@ -199,6 +199,7 @@ m4_include([opcomp06.at])
 AT_BANNER([The -T option])
 m4_include([T-mult.at])
 m4_include([T-nest.at])
+m4_include([T-rec.at])
 m4_include([T-cd.at])
 m4_include([T-empty.at])
 m4_include([T-null.at])