diff --git a/ChangeLog b/ChangeLog
index 3964d4e0..5385d755 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,23 @@
+2008-04-21  Joel E. Denny  <jdenny@ces.clemson.edu>
+
+	Update to the current gnulib CVS repository, and fix trigraph handling
+	in Bison.
+	* bootstrap: Update gnulib CVS repository URL.
+	(symlink_to_dir): Encapsulate the code that guarantees the destination
+	directory exists into...
+	(check_dst_dir): ... this new function, and...
+	(cp_mark_as_generated): ... reuse it here so that bootstrap doesn't
+	fail when copying files into lib/uniwidth/.
+	* src/output.c (prepare_symbols): When writing yytname muscles, where
+	symbol names will be encoded in C-string literals, tell quotearg to
+	escape trigraphs.  This used to be the default in gnulib.
+	* tests/regression.at (Token definitions): Because of the change in
+	gnulib's quotearg behavior, string_as_id in parse-gram.y no longer
+	escapes trigraphs in symbol names.  Thus, yytname no longer has
+	trigraphs unnecessarily doubly escaped.  Update test case output.
+	Extend test case to be sure Bison's own error messages will no longer
+	have trigraphs in symbol names unnecessarily escaped once.
+
 2008-04-20  Joel E. Denny  <jdenny@ces.clemson.edu>
 
 	Fix make dist infinite loop reported by Juan Manuel Guerrero at
diff --git a/bootstrap b/bootstrap
index e0ac7c75..9923ff04 100755
--- a/bootstrap
+++ b/bootstrap
@@ -2,7 +2,8 @@
 
 # Bootstrap this package from checked-out sources.
 
-# Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+# Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation,
+# Inc.
 
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -274,7 +275,7 @@ case ${GNULIB_SRCDIR--} in
 
     trap cleanup_gnulib 1 2 13 15
 
-    cvs -z3 -q -d ${CVS_PREFIX}cvs.savannah.gnu.org:/cvsroot/gnulib co gnulib ||
+    cvs -z3 -q -d ${CVS_PREFIX}pserver.git.sv.gnu.org:/gnulib.git co -d gnulib HEAD ||
       cleanup_gnulib
 
     trap - 1 2 13 15
@@ -333,6 +334,27 @@ case $SKIP_PO in
   fi;;
 esac
 
+check_dst_dir()
+{
+  dst=$1
+  # If the destination directory doesn't exist, create it.
+  # This is required at least for "lib/uniwidth/cjk.h".
+  dst_dir=`dirname "$dst"`
+  if ! test -d "$dst_dir"; then
+    mkdir -p "$dst_dir"
+
+    # If we've just created a directory like lib/uniwidth,
+    # tell version control system(s) it's ignorable.
+    # FIXME: for now, this does only one level
+    parent=`dirname "$dst_dir"`
+    for dot_ig in x $vc_ignore; do
+      test $dot_ig = x && continue
+      ig=$parent/$dot_ig
+      insert_sorted_if_absent $ig `echo "$dst_dir"|sed 's,.*/,,'`
+    done
+  fi
+}
+
 symlink_to_dir()
 {
   src=$1/$2
@@ -340,22 +362,7 @@ symlink_to_dir()
 
   test -f "$src" && {
 
-    # If the destination directory doesn't exist, create it.
-    # This is required at least for "lib/uniwidth/cjk.h".
-    dst_dir=`dirname "$dst"`
-    if ! test -d "$dst_dir"; then
-      mkdir -p "$dst_dir"
-
-      # If we've just created a directory like lib/uniwidth,
-      # tell version control system(s) it's ignorable.
-      # FIXME: for now, this does only one level
-      parent=`dirname "$dst_dir"`
-      for dot_ig in x $vc_ignore; do
-	test $dot_ig = x && continue
-	ig=$parent/$dot_ig
-	insert_sorted_if_absent $ig `echo "$dst_dir"|sed 's,.*/,,'`
-      done
-    fi
+    check_dst_dir "$dst"
 
     if $copy; then
       {
@@ -419,6 +426,7 @@ cp_mark_as_generated()
 	sed "s!$bt_regex/!!g" "$cp_src" > "$cp_dst"
       }
     else
+      check_dst_dir "$cp_dst"
       # Copy the file first to get proper permissions if it
       # doesn't already exist.  Then overwrite the copy.
       cp "$cp_src" "$cp_dst-t" &&
diff --git a/lib/.cvsignore b/lib/.cvsignore
index b5f830ef..fa0fe44d 100644
--- a/lib/.cvsignore
+++ b/lib/.cvsignore
@@ -25,6 +25,7 @@ fd-safer.c
 fopen-safer.c
 getopt.c
 getopt.h
+getopt.in.h
 getopt1.c
 getopt_.h
 getopt_int.h
@@ -32,7 +33,9 @@ gettext.h
 gnulib.mk
 hash.c
 hash.h
+intprops.h
 inttypes.h
+inttypes.in.h
 inttypes_.h
 localcharset.c
 localcharset.h
@@ -52,17 +55,21 @@ ref-del.sed
 ref-del.sin
 stamp-h1
 stdbool.h
+stdbool.in.h
 stdbool_.h
 stdint.h
+stdint.in.h
 stdint_.h
 stdio--.h
 stdio-safer.h
 stdlib.h
+stdlib.in.h
 stdlib_.h
 stpcpy.c
 streq.h
 strerror.c
 string.h
+string.in.h
 string_.h
 stripslash.c
 strndup.c
@@ -74,6 +81,7 @@ strverscmp.h
 unistd--.h
 unistd-safer.h
 unistd.h
+unistd.in.h
 unistd_.h
 unitypes.h
 uniwidth
@@ -81,8 +89,10 @@ uniwidth.h
 unlocked-io.h
 verify.h
 wchar.h
+wchar.in.h
 wchar_.h
 wctype.h
+wctype.in.h
 wctype_.h
 wcwidth.c
 wcwidth.h
diff --git a/src/output.c b/src/output.c
index 1a1d7b3a..043298bb 100644
--- a/src/output.c
+++ b/src/output.c
@@ -1,7 +1,7 @@
 /* Output the generated parsing program for Bison.
 
    Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002, 2003, 2004,
-   2005, 2006, 2007 Free Software Foundation, Inc.
+   2005, 2006, 2007, 2008 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -156,9 +156,12 @@ prepare_symbols (void)
     int i;
     /* We assume that the table will be output starting at column 2. */
     int j = 2;
+    struct quoting_options *qo = clone_quoting_options (0);
+    set_quoting_style (qo, c_quoting_style);
+    set_quoting_flags (qo, QA_SPLIT_TRIGRAPHS);
     for (i = 0; i < nsyms; i++)
       {
-	char const *cp = quotearg_style (c_quoting_style, symbols[i]->tag);
+	char *cp = quotearg_alloc (symbols[i]->tag, -1, qo);
 	/* Width of the next token, including the two quotes, the
 	   comma and the space.  */
 	int width = strlen (cp) + 2;
@@ -172,9 +175,11 @@ prepare_symbols (void)
 	if (i)
 	  obstack_1grow (&format_obstack, ' ');
 	MUSCLE_OBSTACK_SGROW (&format_obstack, cp);
+        free (cp);
 	obstack_1grow (&format_obstack, ',');
 	j += width;
       }
+    free (qo);
     obstack_sgrow (&format_obstack, " ]b4_null[");
 
     /* Finish table and store. */
diff --git a/src/parse-gram.c b/src/parse-gram.c
index 0ec62862..6425f22d 100644
--- a/src/parse-gram.c
+++ b/src/parse-gram.c
@@ -1691,7 +1691,7 @@ YYLTYPE yylloc;
 
 /* User initialization code.  */
 
-/* Line 1247 of yacc.c  */
+/* Line 1243 of yacc.c  */
 #line 86 "parse-gram.y"
 {
   /* Bison's grammar can initial empty locations, hence a default
@@ -1700,7 +1700,7 @@ YYLTYPE yylloc;
   boundary_set (&yylloc.end, current_file, 1, 1);
 }
 
-/* Line 1247 of yacc.c  */
+/* Line 1243 of yacc.c  */
 #line 1705 "parse-gram.c"
   yylsp[0] = yylloc;
 
@@ -1888,7 +1888,7 @@ yyreduce:
     {
         case 6:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 220 "parse-gram.y"
     {
       code_props plain_code;
@@ -1903,14 +1903,14 @@ yyreduce:
 
   case 7:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 229 "parse-gram.y"
     { debug_flag = true; }
     break;
 
   case 8:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 231 "parse-gram.y"
     {
       muscle_percent_define_insert ((yyvsp[(2) - (3)].uniqstr), (yylsp[(2) - (3)]), (yyvsp[(3) - (3)].chars));
@@ -1919,14 +1919,14 @@ yyreduce:
 
   case 9:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 234 "parse-gram.y"
     { defines_flag = true; }
     break;
 
   case 10:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 236 "parse-gram.y"
     {
       defines_flag = true;
@@ -1936,42 +1936,42 @@ yyreduce:
 
   case 11:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 240 "parse-gram.y"
     { error_verbose = true; }
     break;
 
   case 12:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 241 "parse-gram.y"
     { expected_sr_conflicts = (yyvsp[(2) - (2)].integer); }
     break;
 
   case 13:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 242 "parse-gram.y"
     { expected_rr_conflicts = (yyvsp[(2) - (2)].integer); }
     break;
 
   case 14:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 243 "parse-gram.y"
     { spec_file_prefix = (yyvsp[(2) - (2)].chars); }
     break;
 
   case 15:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 244 "parse-gram.y"
     { spec_file_prefix = (yyvsp[(3) - (3)].chars); }
     break;
 
   case 16:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 246 "parse-gram.y"
     {
       nondeterministic_parser = true;
@@ -1981,7 +1981,7 @@ yyreduce:
 
   case 17:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 251 "parse-gram.y"
     {
       code_props action;
@@ -1995,77 +1995,77 @@ yyreduce:
 
   case 18:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 259 "parse-gram.y"
     { language_argmatch ((yyvsp[(2) - (2)].chars), 1, &(yylsp[(1) - (2)])); }
     break;
 
   case 19:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 260 "parse-gram.y"
     { add_param ("lex_param", (yyvsp[(2) - (2)].code), (yylsp[(2) - (2)])); }
     break;
 
   case 20:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 261 "parse-gram.y"
     { locations_flag = true; }
     break;
 
   case 21:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 262 "parse-gram.y"
     { spec_name_prefix = (yyvsp[(2) - (2)].chars); }
     break;
 
   case 22:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 263 "parse-gram.y"
     { spec_name_prefix = (yyvsp[(3) - (3)].chars); }
     break;
 
   case 23:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 264 "parse-gram.y"
     { no_lines_flag = true; }
     break;
 
   case 24:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 265 "parse-gram.y"
     { nondeterministic_parser = true; }
     break;
 
   case 25:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 266 "parse-gram.y"
     { spec_outfile = (yyvsp[(2) - (2)].chars); }
     break;
 
   case 26:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 267 "parse-gram.y"
     { spec_outfile = (yyvsp[(3) - (3)].chars); }
     break;
 
   case 27:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 268 "parse-gram.y"
     { add_param ("parse_param", (yyvsp[(2) - (2)].code), (yylsp[(2) - (2)])); }
     break;
 
   case 28:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 270 "parse-gram.y"
     {
       /* %pure-parser is deprecated in favor of `%define api.pure', so use
@@ -2083,14 +2083,14 @@ yyreduce:
 
   case 29:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 282 "parse-gram.y"
     { version_check (&(yylsp[(2) - (2)]), (yyvsp[(2) - (2)].chars)); }
     break;
 
   case 30:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 284 "parse-gram.y"
     {
       char const *skeleton_user = (yyvsp[(2) - (2)].chars);
@@ -2119,28 +2119,28 @@ yyreduce:
 
   case 31:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 307 "parse-gram.y"
     { token_table_flag = true; }
     break;
 
   case 32:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 308 "parse-gram.y"
     { report_flag |= report_states; }
     break;
 
   case 33:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 309 "parse-gram.y"
     { yacc_flag = true; }
     break;
 
   case 37:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 317 "parse-gram.y"
     {
       grammar_start_symbol_set ((yyvsp[(2) - (2)].symbol), (yylsp[(2) - (2)]));
@@ -2149,7 +2149,7 @@ yyreduce:
 
   case 38:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 321 "parse-gram.y"
     {
       symbol_list *list;
@@ -2161,7 +2161,7 @@ yyreduce:
 
   case 39:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 328 "parse-gram.y"
     {
       symbol_list *list;
@@ -2173,7 +2173,7 @@ yyreduce:
 
   case 40:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 335 "parse-gram.y"
     {
       default_prec = true;
@@ -2182,7 +2182,7 @@ yyreduce:
 
   case 41:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 339 "parse-gram.y"
     {
       default_prec = false;
@@ -2191,7 +2191,7 @@ yyreduce:
 
   case 42:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 343 "parse-gram.y"
     {
       /* Do not invoke muscle_percent_code_grow here since it invokes
@@ -2203,7 +2203,7 @@ yyreduce:
 
   case 43:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 350 "parse-gram.y"
     {
       muscle_percent_code_grow ((yyvsp[(2) - (3)].uniqstr), (yylsp[(2) - (3)]), (yyvsp[(3) - (3)].chars), (yylsp[(3) - (3)]));
@@ -2213,21 +2213,21 @@ yyreduce:
 
   case 44:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 364 "parse-gram.y"
     {}
     break;
 
   case 45:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 365 "parse-gram.y"
     { muscle_code_grow ("union_name", (yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
     break;
 
   case 46:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 370 "parse-gram.y"
     {
       union_seen = true;
@@ -2238,14 +2238,14 @@ yyreduce:
 
   case 47:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 381 "parse-gram.y"
     { current_class = nterm_sym; }
     break;
 
   case 48:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 382 "parse-gram.y"
     {
       current_class = unknown_sym;
@@ -2255,14 +2255,14 @@ yyreduce:
 
   case 49:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 386 "parse-gram.y"
     { current_class = token_sym; }
     break;
 
   case 50:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 387 "parse-gram.y"
     {
       current_class = unknown_sym;
@@ -2272,7 +2272,7 @@ yyreduce:
 
   case 51:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 392 "parse-gram.y"
     {
       symbol_list *list;
@@ -2285,7 +2285,7 @@ yyreduce:
 
   case 52:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 403 "parse-gram.y"
     {
       symbol_list *list;
@@ -2302,126 +2302,126 @@ yyreduce:
 
   case 53:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 417 "parse-gram.y"
     { (yyval.assoc) = left_assoc; }
     break;
 
   case 54:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 418 "parse-gram.y"
     { (yyval.assoc) = right_assoc; }
     break;
 
   case 55:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 419 "parse-gram.y"
     { (yyval.assoc) = non_assoc; }
     break;
 
   case 56:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 423 "parse-gram.y"
     { current_type = NULL; }
     break;
 
   case 57:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 424 "parse-gram.y"
     { current_type = (yyvsp[(1) - (1)].uniqstr); tag_seen = true; }
     break;
 
   case 58:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 430 "parse-gram.y"
     { (yyval.list) = symbol_list_sym_new ((yyvsp[(1) - (1)].symbol), (yylsp[(1) - (1)])); }
     break;
 
   case 59:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 432 "parse-gram.y"
     { (yyval.list) = symbol_list_prepend ((yyvsp[(1) - (2)].list), symbol_list_sym_new ((yyvsp[(2) - (2)].symbol), (yylsp[(2) - (2)]))); }
     break;
 
   case 60:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 436 "parse-gram.y"
     { (yyval.symbol) = (yyvsp[(1) - (1)].symbol); }
     break;
 
   case 61:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 437 "parse-gram.y"
     { (yyval.symbol) = (yyvsp[(1) - (2)].symbol); symbol_user_token_number_set ((yyvsp[(1) - (2)].symbol), (yyvsp[(2) - (2)].integer), (yylsp[(2) - (2)])); }
     break;
 
   case 62:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 443 "parse-gram.y"
     { (yyval.list) = symbol_list_sym_new ((yyvsp[(1) - (1)].symbol), (yylsp[(1) - (1)])); }
     break;
 
   case 63:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 445 "parse-gram.y"
     { (yyval.list) = symbol_list_prepend ((yyvsp[(1) - (2)].list), symbol_list_sym_new ((yyvsp[(2) - (2)].symbol), (yylsp[(2) - (2)]))); }
     break;
 
   case 64:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 449 "parse-gram.y"
     { (yyval.list) = (yyvsp[(1) - (1)].list); }
     break;
 
   case 65:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 450 "parse-gram.y"
     { (yyval.list) = symbol_list_prepend ((yyvsp[(1) - (2)].list), (yyvsp[(2) - (2)].list)); }
     break;
 
   case 66:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 454 "parse-gram.y"
     { (yyval.list) = symbol_list_sym_new ((yyvsp[(1) - (1)].symbol), (yylsp[(1) - (1)])); }
     break;
 
   case 67:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 455 "parse-gram.y"
     { (yyval.list) = symbol_list_type_new ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
     break;
 
   case 68:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 456 "parse-gram.y"
     { (yyval.list) = symbol_list_default_tagged_new ((yylsp[(1) - (1)])); }
     break;
 
   case 69:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 457 "parse-gram.y"
     { (yyval.list) = symbol_list_default_tagless_new ((yylsp[(1) - (1)])); }
     break;
 
   case 70:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 463 "parse-gram.y"
     {
        current_type = (yyvsp[(1) - (1)].uniqstr);
@@ -2431,7 +2431,7 @@ yyreduce:
 
   case 71:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 468 "parse-gram.y"
     {
        symbol_class_set ((yyvsp[(1) - (1)].symbol), current_class, (yylsp[(1) - (1)]), true);
@@ -2441,7 +2441,7 @@ yyreduce:
 
   case 72:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 473 "parse-gram.y"
     {
       symbol_class_set ((yyvsp[(1) - (2)].symbol), current_class, (yylsp[(1) - (2)]), true);
@@ -2452,7 +2452,7 @@ yyreduce:
 
   case 73:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 479 "parse-gram.y"
     {
       symbol_class_set ((yyvsp[(1) - (2)].symbol), current_class, (yylsp[(1) - (2)]), true);
@@ -2463,7 +2463,7 @@ yyreduce:
 
   case 74:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 485 "parse-gram.y"
     {
       symbol_class_set ((yyvsp[(1) - (3)].symbol), current_class, (yylsp[(1) - (3)]), true);
@@ -2475,7 +2475,7 @@ yyreduce:
 
   case 81:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 515 "parse-gram.y"
     {
       yyerrok;
@@ -2484,77 +2484,77 @@ yyreduce:
 
   case 82:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 521 "parse-gram.y"
     { current_lhs = (yyvsp[(1) - (1)].symbol); current_lhs_location = (yylsp[(1) - (1)]); }
     break;
 
   case 84:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 525 "parse-gram.y"
     { grammar_current_rule_end ((yylsp[(1) - (1)])); }
     break;
 
   case 85:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 526 "parse-gram.y"
     { grammar_current_rule_end ((yylsp[(3) - (3)])); }
     break;
 
   case 87:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 532 "parse-gram.y"
     { grammar_current_rule_begin (current_lhs, current_lhs_location); }
     break;
 
   case 88:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 534 "parse-gram.y"
     { grammar_current_rule_symbol_append ((yyvsp[(2) - (2)].symbol), (yylsp[(2) - (2)])); }
     break;
 
   case 89:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 536 "parse-gram.y"
     { grammar_current_rule_action_append ((yyvsp[(2) - (2)].code), (yylsp[(2) - (2)])); }
     break;
 
   case 90:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 538 "parse-gram.y"
     { grammar_current_rule_prec_set ((yyvsp[(3) - (3)].symbol), (yylsp[(3) - (3)])); }
     break;
 
   case 91:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 540 "parse-gram.y"
     { grammar_current_rule_dprec_set ((yyvsp[(3) - (3)].integer), (yylsp[(3) - (3)])); }
     break;
 
   case 92:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 542 "parse-gram.y"
     { grammar_current_rule_merge_set ((yyvsp[(3) - (3)].uniqstr), (yylsp[(3) - (3)])); }
     break;
 
   case 94:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 552 "parse-gram.y"
     { (yyval.uniqstr) = uniqstr_new ((yyvsp[(1) - (1)].chars)); }
     break;
 
   case 95:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 558 "parse-gram.y"
     {
       (yyval.chars) = "";
@@ -2563,7 +2563,7 @@ yyreduce:
 
   case 97:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 571 "parse-gram.y"
     {
       code_props plain_code;
@@ -2577,14 +2577,14 @@ yyreduce:
 
   case 98:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 591 "parse-gram.y"
     { (yyval.symbol) = symbol_from_uniqstr ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
     break;
 
   case 99:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 593 "parse-gram.y"
     {
       (yyval.symbol) = symbol_get (char_name ((yyvsp[(1) - (1)].character)), (yylsp[(1) - (1)]));
@@ -2595,14 +2595,14 @@ yyreduce:
 
   case 100:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 601 "parse-gram.y"
     { (yyval.symbol) = symbol_from_uniqstr ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
     break;
 
   case 103:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 613 "parse-gram.y"
     {
       (yyval.symbol) = symbol_get (quotearg_style (c_quoting_style, (yyvsp[(1) - (1)].chars)), (yylsp[(1) - (1)]));
@@ -2612,7 +2612,7 @@ yyreduce:
 
   case 105:
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 622 "parse-gram.y"
     {
       code_props plain_code;
@@ -2626,7 +2626,7 @@ yyreduce:
 
 
 
-/* Line 1464 of yacc.c  */
+/* Line 1460 of yacc.c  */
 #line 2631 "parse-gram.c"
       default: break;
     }
@@ -2845,7 +2845,7 @@ yyreturn:
 
 
 
-/* Line 1684 of yacc.c  */
+/* Line 1680 of yacc.c  */
 #line 632 "parse-gram.y"
 
 
diff --git a/src/parse-gram.h b/src/parse-gram.h
index d8169eb8..86ac4b52 100644
--- a/src/parse-gram.h
+++ b/src/parse-gram.h
@@ -160,7 +160,7 @@
 typedef union YYSTYPE
 {
 
-/* Line 1685 of yacc.c  */
+/* Line 1681 of yacc.c  */
 #line 94 "parse-gram.y"
 
   symbol *symbol;
@@ -174,7 +174,7 @@ typedef union YYSTYPE
 
 
 
-/* Line 1685 of yacc.c  */
+/* Line 1681 of yacc.c  */
 #line 179 "parse-gram.h"
 } YYSTYPE;
 # define YYSTYPE_IS_TRIVIAL 1
diff --git a/tests/regression.at b/tests/regression.at
index a3e7d4f7..51bf3f30 100644
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -444,6 +444,7 @@ int yylex (void);
 %token C_TOKEN 'c'
 %token 'd' D_TOKEN
 %token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
+%token SPECIAL "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!"
 %%
 exp: "a" "\\\'\?\"\a\b\f\n\r\t\v\001\201\x001\x000081??!";
 %%
@@ -469,10 +470,22 @@ main (void)
 }
 ]])
 
-AT_BISON_CHECK([-o input.c input.y])
+# Checking the warning message guarantees that the trigraph "??!" isn't
+# unnecessarily escaped here even though it would need to be if encoded in a
+# C-string literal.  Also notice that unnecessary escaping, such as "\?", from
+# the user specification is eliminated.
+AT_BISON_CHECK([-o input.c input.y], [[0]], [[]],
+[[input.y:22.8-14: warning: symbol SPECIAL redeclared
+input.y:22.8-63: warning: symbol `"\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!"' used more than once as a literal string
+]])
 AT_COMPILE([input])
+
+# Checking the error message here guarantees that yytname, which does contain
+# C-string literals, does have the trigraph escaped correctly.  Thus, the
+# symbol name reported by the parser is exactly the same as that reported by
+# Bison itself.
 AT_DATA([experr],
-[[syntax error, unexpected "\\'?\"\a\b\f\n\r\t\v\001\201\001\201?\?!", expecting a
+[[syntax error, unexpected "\\'?\"\a\b\f\n\r\t\v\001\201\001\201??!", expecting a
 ]])
 AT_PARSER_CHECK([./input], 1, [], [experr])
 AT_CLEANUP