Stage 28b: Warn on embedded NUL in file arguments.

* m4/path.c (m4_path_search): Quote file names in message.
* modules/m4.c (syscmd, include, m4_make_temp): Handle embedded
NUL.
* modules/gnu.c (debugfile, esyscmd): Likewise.
* tests/others.at (nul character): Adjust test.
* tests/builtins.at (mkdtemp, mkstemp): Likewise.
* tests/null.m4: Likewise.
* tests/null.out: Likewise.
* tests/null.err: Likewise.

Signed-off-by: Eric Blake <ebb9@byu.net>

9 files changed, 72 insertions, 23 deletions

diff --git a/ChangeLog b/ChangeLog
index def85f5c..29fc9ef4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,20 @@
 2009-02-11  Eric Blake  <ebb9@byu.net>
 
+	Stage 28b: Warn on embedded NUL in file arguments.
+	Quote warning messages related to file and other NUL-terminated
+	system commands.
+	Memory impact: none.
+	Speed impact: none noticed.
+	* m4/path.c (m4_path_search): Quote file names in message.
+	* modules/m4.c (syscmd, include, m4_make_temp): Handle embedded
+	NUL.
+	* modules/gnu.c (debugfile, esyscmd): Likewise.
+	* tests/others.at (nul character): Adjust test.
+	* tests/builtins.at (mkdtemp, mkstemp): Likewise.
+	* tests/null.m4: Likewise.
+	* tests/null.out: Likewise.
+	* tests/null.err: Likewise.
+
 	Stage 28a: Warn on embedded NUL in numeric arguments.
 	Quote warning messages related to numeric parsing in order to
 	handle embedded NUL.
diff --git a/m4/path.c b/m4/path.c
index bf151935..c83aa214 100644
--- a/m4/path.c
+++ b/m4/path.c
@@ -1,6 +1,6 @@
 /* GNU m4 -- A simple macro processor
    Copyright (C) 1989, 1990, 1991, 1992, 1993, 1998, 2004, 2006, 2007,
-   2008 Free Software Foundation, Inc.
+   2008, 2009 Free Software Foundation, Inc.
 
    This file is part of GNU M4.
 
@@ -198,8 +198,9 @@ m4_path_search (m4 *context, const char *file, char **expanded_name)
       if (fp != NULL)
 	{
 	  m4_debug_message (context, M4_DEBUG_TRACE_PATH,
-			    _("path search for `%s' found `%s'"),
-			    file, name);
+			    _("path search for %s found %s"),
+			    quotearg_style (locale_quoting_style, file),
+			    quotearg_n_style (1, locale_quoting_style, name));
 	  if (expanded_name != NULL)
 	    *expanded_name = name;
 	  else
diff --git a/modules/gnu.c b/modules/gnu.c
index ce14532b..69d938f1 100644
--- a/modules/gnu.c
+++ b/modules/gnu.c
@@ -583,9 +583,17 @@ M4BUILTIN_HANDLER (debugfile)
     m4_debug_set_output (context, me, NULL);
   else if (m4_get_safer_opt (context) && !m4_arg_empty (argv, 1))
     m4_error (context, 0, 0, me, _("disabled by --safer"));
-  else if (!m4_debug_set_output (context, me, M4ARG (1)))
-    m4_error (context, 0, errno, me, _("cannot set debug file %s"),
-	      quotearg_style (locale_quoting_style, M4ARG (1)));
+  else
+    {
+      const char *str = M4ARG (1);
+      size_t len = M4ARGLEN (1);
+      if (strlen (str) < len)
+	m4_warn (context, 0, me, _("argument %s truncated"),
+		 quotearg_style_mem (locale_quoting_style, str, len));
+      if (!m4_debug_set_output (context, me, str))
+	m4_warn (context, errno, me, _("cannot set debug file %s"),
+	      quotearg_style (locale_quoting_style, str));
+    }
 }
 
 
@@ -635,6 +643,8 @@ M4BUILTIN_HANDLER (debugmode)
 M4BUILTIN_HANDLER (esyscmd)
 {
   const m4_call_info *me = m4_arg_info (argv);
+  const char *cmd = M4ARG (1);
+  size_t len = M4ARGLEN (1);
   M4_MODULE_IMPORT (m4, m4_set_sysval);
   M4_MODULE_IMPORT (m4, m4_sysval_flush);
 
@@ -648,9 +658,12 @@ M4BUILTIN_HANDLER (esyscmd)
 	  m4_error (context, 0, 0, me, _("disabled by --safer"));
 	  return;
 	}
+      if (strlen (cmd) != len)
+	m4_warn (context, 0, me, _("argument %s truncated"),
+		 quotearg_style_mem (locale_quoting_style, cmd, len));
 
       /* Optimize the empty command.  */
-      if (m4_arg_empty (argv, 1))
+      if (!*cmd)
 	{
 	  m4_set_sysval (0);
 	  return;
@@ -658,11 +671,12 @@ M4BUILTIN_HANDLER (esyscmd)
 
       m4_sysval_flush (context, false);
       errno = 0;
-      pin = popen (M4ARG (1), "r");
+      pin = popen (cmd, "r");
       if (pin == NULL)
 	{
 	  m4_error (context, 0, errno, me,
-		    _("cannot open pipe to command `%s'"), M4ARG (1));
+		    _("cannot open pipe to command %s"),
+		    quotearg_style (locale_quoting_style, cmd));
 	  m4_set_sysval (-1);
 	}
       else
diff --git a/modules/m4.c b/modules/m4.c
index 44e8a0ae..8ce419db 100644
--- a/modules/m4.c
+++ b/modules/m4.c
@@ -504,20 +504,27 @@ m4_sysval_flush (m4 *context, bool report)
 
 M4BUILTIN_HANDLER (syscmd)
 {
+  const m4_call_info *me = m4_arg_info (argv);
+  const char *cmd = M4ARG (1);
+  size_t len = M4ARGLEN (1);
+
   if (m4_get_safer_opt (context))
     {
       m4_error (context, 0, 0, m4_arg_info (argv), _("disabled by --safer"));
       return;
     }
+  if (strlen (cmd) != len)
+    m4_warn (context, 0, me, _("argument %s truncated"),
+	     quotearg_style_mem (locale_quoting_style, cmd, len));
 
   /* Optimize the empty command.  */
-  if (m4_arg_empty (argv, 1))
+  if (!*cmd)
     {
       m4_set_sysval (0);
       return;
     }
   m4_sysval_flush (context, false);
-  m4_sysval = system (M4ARG (1));
+  m4_sysval = system (cmd);
   /* FIXME - determine if libtool works for OS/2, in which case the
      FUNC_SYSTEM_BROKEN section on the branch must be ported to work
      around the bug in their EMX libc system().  */
@@ -672,13 +679,19 @@ include (m4 *context, int argc, m4_macro_args *argv, bool silent)
 {
   FILE *fp;
   char *name = NULL;
+  const m4_call_info *me = m4_arg_info (argv);
+  const char *arg = M4ARG (1);
+  size_t len = M4ARGLEN (1);
 
-  fp = m4_path_search (context, M4ARG (1), &name);
+  if (strlen (arg) != len)
+    m4_warn (context, 0, me, _("argument %s truncated"),
+	     quotearg_style_mem (locale_quoting_style, arg, len));
+  fp = m4_path_search (context, arg, &name);
   if (fp == NULL)
     {
       if (!silent)
 	m4_error (context, 0, errno, m4_arg_info (argv), _("cannot open %s"),
-		  quotearg_style (locale_quoting_style, M4ARG (1)));
+		  quotearg_style (locale_quoting_style, arg));
       return;
     }
 
@@ -725,6 +738,12 @@ m4_make_temp (m4 *context, m4_obstack *obs, const m4_call_info *caller,
      successful.  */
   assert (obstack_object_size (obs) == 0);
   obstack_grow (obs, quotes->str1, quotes->len1);
+  if (strlen (pattern) < len)
+    {
+      m4_warn (context, 0, caller, _("argument %s truncated"),
+	       quotearg_style_mem (locale_quoting_style, pattern, len));
+      len = strlen (pattern);
+    }
   obstack_grow (obs, pattern, len);
   for (i = 0; len > 0 && i < 6; i++)
     if (pattern[--len] != 'X')
@@ -740,10 +759,10 @@ m4_make_temp (m4 *context, m4_obstack *obs, const m4_call_info *caller,
       /* This use of _() will need to change if xgettext ever changes
 	 its undocumented behavior of parsing both string options.  */
 
-      m4_error (context, 0, errno, caller,
-		_(dir ? "cannot create directory from template `%s'"
-		  : "cannot create file from template `%s'"),
-		pattern);
+      m4_warn (context, errno, caller,
+	       _(dir ? "cannot create directory from template %s"
+		 : "cannot create file from template %s"),
+	       quotearg_style (locale_quoting_style, pattern));
       obstack_free (obs, obstack_finish (obs));
     }
   else
diff --git a/tests/builtins.at b/tests/builtins.at
index f819403b..397f649c 100644
--- a/tests/builtins.at
+++ b/tests/builtins.at
@@ -1,5 +1,5 @@
 # Hand crafted tests for GNU M4.                               -*- Autotest -*-
-# Copyright (C) 2001, 2006, 2007, 2008 Free Software Foundation, Inc.
+# Copyright (C) 2001, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
 
 # This file is part of GNU M4.
 #
@@ -713,8 +713,8 @@ dnl Check that on error, the expansion is void
 AT_DATA([[in]],
 [[mkdtemp(`no_such_dir/m4-fooXXXXXX')
 ]])
-AT_CHECK_M4([in], [1], [[
-]], [[m4:in:1: mkdtemp: cannot create directory from template `no_such_dir/m4-fooXXXXXX': No such file or directory
+AT_CHECK_M4([in], [0], [[
+]], [[m4:in:1: Warning: mkdtemp: cannot create directory from template `no_such_dir/m4-fooXXXXXX': No such file or directory
 ]])
 
 dnl Check that umask has an effect.  drws--S--T is okay.
@@ -742,8 +742,8 @@ dnl Check that on error, the expansion is void
 AT_DATA([[in]],
 [[mkstemp(`no_such_dir/m4-fooXXXXXX')
 ]])
-AT_CHECK_M4([in], [1], [[
-]], [[m4:in:1: mkstemp: cannot create file from template `no_such_dir/m4-fooXXXXXX': No such file or directory
+AT_CHECK_M4([in], [0], [[
+]], [[m4:in:1: Warning: mkstemp: cannot create file from template `no_such_dir/m4-fooXXXXXX': No such file or directory
 ]])
 
 dnl Check that extra X are appended, but not trailing NUL
diff --git a/tests/null.err b/tests/null.err
index edad891e..01f2a8e7 100644
--- a/tests/null.err
+++ b/tests/null.err
diff --git a/tests/null.m4 b/tests/null.m4
index 3d57806e..60711449 100644
--- a/tests/null.m4
+++ b/tests/null.m4
diff --git a/tests/null.out b/tests/null.out
index cfb78c04..3859b239 100644
--- a/tests/null.out
+++ b/tests/null.out
diff --git a/tests/others.at b/tests/others.at
index 3f123516..779fd3cc 100644
--- a/tests/others.at
+++ b/tests/others.at
@@ -430,7 +430,7 @@ $SED "s|null.m4|$abs_srcdir/null.m4|" < "$abs_srcdir/null.out" > expout
 $SED "s|null.m4|$abs_srcdir/null.m4|" < "$abs_srcdir/null.err" > experr
 
 dnl all but m4exit
-AT_CHECK_M4([-Dm4exit -I "$abs_srcdir" null.m4], [0], [expout], [experr])
+AT_CHECK_M4([-Dm4exit -I "$abs_srcdir" null.m4], [1], [expout], [experr])
 
 dnl just m4exit
 AT_CHECK_M4(["$abs_srcdir/null.m4"], [1],