diff --git a/ChangeLog b/ChangeLog
index 8fa43858..3a683551 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,28 @@
+2006-08-18  Joel E. Denny  <jdenny@ces.clemson.edu>
+
+	Don't allow an undeclared string literal, but allow a string literal to
+	be used before its declaration.
+	* src/reader.c (check_and_convert_grammar): Don't invoke packgram if
+	symbols_pack complained.
+	* src/symtab.c (symbol_new): Don't count a string literal as a new
+	symbol.
+	(symbol_class_set): Don't count a string literal as a new token, and
+	don't assign it a symbol number since symbol_make_alias does that.
+	(symbol_make_alias): It's not necessary to decrement the symbol and
+	token counts anymore.  Don't assume that an alias declaration occurs
+	before any uses of the identifier or string, and thus don't assert that
+	one of them has the highest symbol number so far.
+	(symbol_check_alias_consistency): Complain if there's a string literal
+	that wasn't declared as an alias.
+	(symbols_pack): Bail if symbol_check_alias_consistency failed since
+	symbol_pack asserts that every token has been assigned a symbol number
+	although undeclared string literals have not.
+	* tests/regression.at (String alias declared after use, Undeclared
+	string literal): New test case.
+	(Characters Escapes, Web2c Actions): Declare string literals as
+	aliases.
+	* tests/sets.at (Firsts): Likewise.
+
 2006-08-14  Joel E. Denny  <jdenny@ces.clemson.edu>
 
 	In the grammar scanner, STRING_FINISH unclosed constructs and return
diff --git a/src/reader.c b/src/reader.c
index 5084618f..e31fe4c5 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -630,7 +630,8 @@ check_and_convert_grammar (void)
   symbols_pack ();
 
   /* Convert the grammar into the format described in gram.h.  */
-  packgram ();
+  if (!complaint_issued)
+    packgram ();
 
   /* The grammar as a symbol_list is no longer needed. */
   LIST_FREE (symbol_list, grammar);
diff --git a/src/symtab.c b/src/symtab.c
index 8b3e30d3..28f49fb4 100644
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -79,7 +79,8 @@ symbol_new (uniqstr tag, location loc)
   if (nsyms == SYMBOL_NUMBER_MAXIMUM)
     fatal (_("too many symbols in input grammar (limit is %d)"),
 	   SYMBOL_NUMBER_MAXIMUM);
-  nsyms++;
+  if (tag[0] != '"')
+    nsyms++;
   return res;
 }
 
@@ -266,7 +267,8 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
 
   if (class == nterm_sym && sym->class != nterm_sym)
     sym->number = nvars++;
-  else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
+  else if (class == token_sym && sym->number == NUMBER_UNDEFINED
+           && sym->tag[0] != '"')
     sym->number = ntokens++;
 
   sym->class = class;
@@ -361,12 +363,7 @@ symbol_make_alias (symbol *sym, symbol *symval, location loc)
       sym->user_token_number = USER_NUMBER_ALIAS;
       symval->alias = sym;
       sym->alias = symval;
-      /* sym and symval combined are only one symbol.  */
-      nsyms--;
-      ntokens--;
-      assert (ntokens == sym->number || ntokens == symval->number);
-      sym->number = symval->number =
-	(symval->number < sym->number) ? symval->number : sym->number;
+      symval->number = sym->number;
       symbol_type_set (symval, sym->type_name, loc);
     }
 }
@@ -383,6 +380,9 @@ symbol_check_alias_consistency (symbol *this)
   symbol *alias = this;
   symbol *orig  = this->alias;
 
+  if (this->tag[0] == '"' && !this->alias)
+    complain_at (this->location, _("%s undeclared"), this->tag);
+
   /* Check only those that _are_ the aliases.  */
   if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
     return;
@@ -723,6 +723,8 @@ symbols_pack (void)
   symbols = xcalloc (nsyms, sizeof *symbols);
 
   symbols_do (symbol_check_alias_consistency_processor, NULL);
+  if (complaint_issued)
+    return;
   symbols_do (symbol_pack_processor, NULL);
 
   symbols_token_translations_init ();
diff --git a/tests/regression.at b/tests/regression.at
index 923a8933..1c5ccbbf 100644
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -489,7 +489,9 @@ AT_DATA_GRAMMAR([input.y],
 void yyerror (const char *s);
 int yylex (void);
 %}
-[%%
+[%token QUOTES "\""
+%token TICK "'"
+%%
 exp:
   '\'' "\'"
 | '\"' "\""
@@ -700,6 +702,10 @@ statement:  struct_stat;
 struct_stat:  /* empty. */ | if else;
 if: "if" "const" "then" statement;
 else: "else" statement;
+%token IF "if";
+%token CONST "const";
+%token THEN "then";
+%token ELSE "else";
 %%
 ]])
 
@@ -1108,3 +1114,48 @@ Stack now 0
 ]])
 
 AT_CLEANUP
+
+
+
+## --------------------------------- ##
+## String alias declared after use.  ##
+## --------------------------------- ##
+
+AT_SETUP([String alias declared after use])
+
+# Bison once incorrectly asserted that the symbol number for either a token or
+# its alias was the highest symbol number so far at the point of the alias
+# declaration.  That was true unless the declaration appeared after their first
+# uses.
+
+AT_DATA([input.y],
+[[%%
+start: 'a' "A" 'b';
+%token 'a' "A";
+]])
+
+AT_CHECK([bison -t -o input.c input.y])
+
+AT_CLEANUP
+
+
+
+## --------------------------- ##
+## Undeclared string literal.  ##
+## --------------------------- ##
+
+AT_SETUP([Undeclared string literal])
+
+# Bison once allowed a string literal to be used in the grammar without any
+# declaration assigning it as an alias of another token.
+
+AT_DATA([input.y],
+[[%%
+start: "abc";
+]])
+
+AT_CHECK([bison -t -o input.c input.y], [1], [],
+[[input.y:2.8-12: "abc" undeclared
+]])
+
+AT_CLEANUP
diff --git a/tests/sets.at b/tests/sets.at
index a731315b..941d0cc2 100644
--- a/tests/sets.at
+++ b/tests/sets.at
@@ -196,6 +196,7 @@ AT_DATA([input.y],
 [[%nonassoc '<' '>'
 %left '+' '-'
 %right '^' '='
+%token EXP "exp"
 %%
 exp:
    exp '<' exp