Re: Bug#385720: m4: INTERNAL ERROR: recursive push_string (fwd)

Index: NEWS
===================================================================
RCS file: /sources/m4/m4/NEWS,v
retrieving revision 1.1.1.1.2.57
diff -u -p -r1.1.1.1.2.57 NEWS
--- NEWS	25 Aug 2006 14:08:33 -0000	1.1.1.1.2.57
+++ NEWS	4 Sep 2006 13:15:47 -0000
@@ -2,6 +2,11 @@ GNU M4 NEWS - User visible changes.
 Copyright (C) 1992, 1993, 1994, 2004, 2005, 2006 Free Software
 Foundation, Inc.
 
+Version 1.4.7 - ?? ??? 2006, by ??  (CVS version 1.4.6a)
+
+* Fix regression from 1.4.5 in handling a file that ends in a macro
+  expansion without arguments instead of a newline.
+
 Version 1.4.6 - 25 August 2006, by Eric Blake  (CVS version 1.4.5a)
 
 * Fix buffer overruns in regexp and patsubst macros when handed a trailing
Index: configure.ac
===================================================================
RCS file: /sources/m4/m4/configure.ac,v
retrieving revision 1.36.2.25
diff -u -p -r1.36.2.25 configure.ac
--- configure.ac	25 Aug 2006 14:08:33 -0000	1.36.2.25
+++ configure.ac	4 Sep 2006 13:15:47 -0000
@@ -18,7 +18,7 @@
 # 02110-1301  USA
 
 AC_PREREQ([2.60])
-AC_INIT([GNU M4], [1.4.6], [[email protected]])
+AC_INIT([GNU M4], [1.4.6a], [[email protected]])
 AM_INIT_AUTOMAKE([1.9.6 dist-bzip2 gnu])
 PACKAGE=$PACKAGE_TARNAME; AC_SUBST([PACKAGE])
 VERSION=$PACKAGE_VERSION; AC_SUBST([VERSION])
Index: doc/m4.texinfo
===================================================================
RCS file: /sources/m4/m4/doc/m4.texinfo,v
retrieving revision 1.1.1.1.2.70
diff -u -p -r1.1.1.1.2.70 m4.texinfo
--- doc/m4.texinfo	24 Aug 2006 14:27:33 -0000	1.1.1.1.2.70
+++ doc/m4.texinfo	4 Sep 2006 13:15:48 -0000
@@ -360,7 +360,7 @@ addressed some long standing bugs in the
 Then in 2005 Gary V. Vaughan collected together the many
 patches to @acronym{GNU} @code{m4} 1.4 that were floating around the net and
 released 1.4.3 and 1.4.4.  And in 2006, Eric Blake joined the team and
-prepared patches for the release of 1.4.5 and 1.4.6.
+prepared patches for the release of 1.4.5, 1.4.6, and 1.4.7.
 
 Meanwhile, development has continued on new features for @code{m4}, such
 as dynamic module loading and additional builtins.  When complete,
@@ -2724,6 +2724,41 @@ is a restriction on the regular expressi
 @code{changeword}.  This is that if your regular expression accepts
 @samp{foo}, it must also accept @samp{f} and @samp{fo}.
 
+@example
+ifdef(`changeword', `', `errprint(` skipping: no changeword support
+')m4exit(`77')')dnl
+define(`foo
+', `bar
+')
+@result{}
+dnl This example wants to recognize changeword, dnl, and `foo\n'.
+dnl First, we check that our regexp will match.
+regexp(`changeword', `[cd][a-z]*\|foo[
+]')
+@result{}0
+regexp(`foo
+', `[cd][a-z]*\|foo[
+]')
+@result{}0
+regexp(`f', `[cd][a-z]*\|foo[
+]')
+@result{}-1
+foo
+@result{}foo
+changeword(`[cd][a-z]*\|foo[
+]')
+@result{}
+dnl Even though `foo\n' matches, we forgot to allow `f'.
+foo
+@result{}foo
+changeword(`[cd][a-z]*\|fo*[
+]?')
+@result{}
+dnl Now we can call `foo\n'.
+foo
+@result{}bar
+@end example
+
 @code{changeword} has another function.  If the regular expression
 supplied contains any grouped subexpressions, then text outside
 the first of these is discarded before symbol lookup.  So:
Index: src/input.c
===================================================================
RCS file: /sources/m4/m4/src/Attic/input.c,v
retrieving revision 1.1.1.1.2.21
diff -u -p -r1.1.1.1.2.21 input.c
--- src/input.c	23 Aug 2006 11:30:11 -0000	1.1.1.1.2.21
+++ src/input.c	4 Sep 2006 13:15:48 -0000
@@ -455,8 +455,12 @@ peek_input (void)
 		    "INTERNAL ERROR: input stack botch in peek_input ()"));
 	  abort ();
 	}
-      /* End of input source --- pop one level.  */
-      pop_input ();
+      /* End of current input source --- pop one level if another
+	 level still exists.  */
+      if (isp->prev != NULL)
+	pop_input ();
+      else
+	return CHAR_EOF;
     }
 }
 
@@ -783,18 +787,20 @@ next_token (token_data *td)
   obstack_1grow (&token_stack, '\0');
   token_bottom = obstack_finish (&token_stack);
 
+ /* Can't consume character until after CHAR_MACRO is handled.  */
   ch = peek_input ();
   if (ch == CHAR_EOF)
     {
 #ifdef DEBUG_INPUT
       fprintf (stderr, "next_token -> EOF\n");
 #endif
+      next_char ();
       return TOKEN_EOF;
     }
   if (ch == CHAR_MACRO)
     {
       init_macro_token (td);
-      (void) next_char ();
+      next_char ();
 #ifdef DEBUG_INPUT
       fprintf (stderr, "next_token -> MACDEF (%s)\n",
 	       find_builtin_by_addr (TOKEN_DATA_FUNC (td))->name);
@@ -802,7 +808,7 @@ next_token (token_data *td)
       return TOKEN_MACDEF;
     }
 
-  (void) next_char ();
+  next_char (); /* Consume character we already peeked at.  */
   if (MATCH (ch, bcomm.string, TRUE))
     {
       obstack_grow (&token_stack, bcomm.string, bcomm.length);