--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,5 +1,29 @@
 2005-08-31  Paul Eggert  <eggert@cs.ucla.edu>
 
+	* regcomp.c (re_compile_fastmap_iter, init_dfa, init_word_char):
+	(optimize_subexps, lower_subexp):
+	Don't assume 1<<31 has defined behavior on hosts with 32-bit int,
+	since the signed shift might overflow.  Use 1u<<31 instead.
+	* regex_internal.h (bitset_set, bitset_clear, bitset_contain): Likewise.
+	* regexec.c (check_dst_limits_calc_pos_1, check_subexp_matching_top):
+	Likewise.
+	* regcomp.c (optimize_subexps, lower_subexp):
+	Use CHAR_BIT rather than 8, for clarity.
+	* regexec.c (check_dst_limits_calc_pos_1):
+	(check_subexp_matching_top): Likewise.
+	* regcomp.c (init_dfa): Make table_size unsigned, so that we don't
+	have to worry about portability issues when shifting it left.
+	Remove no-longer-needed test for table_size > 0.
+	* regcomp.c (parse_sub_exp): Do not shift more bits than there are
+	in a word, as the resulting behavior is undefined.
+	* regexec.c (check_dst_limits_calc_pos_1): Likewise;
+	in one case, a <= should have been an <, and in another case the
+	whole test was missing.
+	* regex_internal.h (BYTE_BITS): Remove.  All uses changed to
+	the standard name CHAR_BIT.
+	* regexec.c (match_ctx_add_entry): Don't assume that ~0 == -1;
+	this is not true on one's complement and signed-magnitude hosts.
+
 	* regex_internal.h (re_sub_match_top_t): Remove unused member
 	next_last_offset.
 	(struct re_dfa_t): Remove unused member states_alloc.

--- a/lib/regcomp.c
+++ b/lib/regcomp.c
@@ -336,7 +336,7 @@
 	  int i, j, ch;
 	  for (i = 0, ch = 0; i < BITSET_UINTS; ++i)
 	    for (j = 0; j < UINT_BITS; ++j, ++ch)
-	      if (dfa->nodes[node].opr.sbcset[i] & (1 << j))
+	      if (dfa->nodes[node].opr.sbcset[i] & (1u << j))
 		re_set_fastmap (fastmap, icase, ch);
 	}
 #ifdef RE_ENABLE_I18N
@@ -798,7 +798,7 @@
 static reg_errcode_t
 init_dfa (re_dfa_t *dfa, int pat_len)
 {
-  int table_size;
+  unsigned int table_size;
 #ifndef _LIBC
   char *codeset_name;
 #endif
@@ -812,7 +812,7 @@
   dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc);
 
   /*  table_size = 2 ^ ceil(log pat_len) */
-  for (table_size = 1; table_size > 0; table_size <<= 1)
+  for (table_size = 1; ; table_size <<= 1)
     if (table_size > pat_len)
       break;
 
@@ -872,7 +872,7 @@
 	      {
 		wint_t wch = __btowc (ch);
 		if (wch != WEOF)
-		  dfa->sb_char[i] |= 1 << j;
+		  dfa->sb_char[i] |= 1u << j;
 # ifndef _LIBC
 		if (isascii (ch) && wch != ch)
 		  dfa->map_notascii = 1;
@@ -899,7 +899,7 @@
   for (i = 0, ch = 0; i < BITSET_UINTS; ++i)
     for (j = 0; j < UINT_BITS; ++j, ++ch)
       if (isalnum (ch) || ch == '_')
-	dfa->word_char[i] |= 1 << j;
+	dfa->word_char[i] |= 1u << j;
 }
 
 /* Free the work area which are only used while compiling.  */
@@ -1222,8 +1222,8 @@
         node->left->parent = node;
 
       dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx];
-      if (other_idx < 8 * sizeof (dfa->used_bkref_map))
-	dfa->used_bkref_map &= ~(1 << other_idx);
+      if (other_idx < CHAR_BIT * sizeof dfa->used_bkref_map)
+	dfa->used_bkref_map &= ~(1u << other_idx);
     }
 
   return REG_NOERROR;
@@ -1266,8 +1266,8 @@
 	 very common, so we do not lose much.  An example that triggers
 	 this case is the sed "script" /\(\)/x.  */
       && node->left != NULL
-      && (node->token.opr.idx >= 8 * sizeof (dfa->used_bkref_map)
-	  || !(dfa->used_bkref_map & (1 << node->token.opr.idx))))
+      && (node->token.opr.idx >= CHAR_BIT * sizeof dfa->used_bkref_map
+	  || !(dfa->used_bkref_map & (1u << node->token.opr.idx))))
     return node->left;
 
   /* Convert the SUBEXP node to the concatenation of an
@@ -2380,7 +2380,9 @@
       if (BE (*err != REG_NOERROR, 0))
 	return NULL;
     }
-  dfa->completed_bkref_map |= 1 << cur_nsub;
+
+  if (cur_nsub <= '9' - '1')
+    dfa->completed_bkref_map |= 1 << cur_nsub;
 
   tree = create_tree (dfa, tree, NULL, SUBEXP);
   if (BE (tree == NULL, 0))

--- a/lib/regex_internal.h
+++ b/lib/regex_internal.h
@@ -90,8 +90,6 @@
 # define inline
 #endif
 
-/* Number of bits in a byte.  */
-#define BYTE_BITS 8
 /* Number of single byte character.  */
 #define SBC_MAX 256
 
@@ -124,16 +122,16 @@
 extern const size_t __re_error_msgid_idx[] attribute_hidden;
 
 /* Number of bits in an unsinged int.  */
-#define UINT_BITS (sizeof (unsigned int) * BYTE_BITS)
+#define UINT_BITS (sizeof (unsigned int) * CHAR_BIT)
 /* Number of unsigned int in an bit_set.  */
 #define BITSET_UINTS ((SBC_MAX + UINT_BITS - 1) / UINT_BITS)
 typedef unsigned int bitset[BITSET_UINTS];
 typedef unsigned int *re_bitset_ptr_t;
 typedef const unsigned int *re_const_bitset_ptr_t;
 
-#define bitset_set(set,i) (set[i / UINT_BITS] |= 1 << i % UINT_BITS)
-#define bitset_clear(set,i) (set[i / UINT_BITS] &= ~(1 << i % UINT_BITS))
-#define bitset_contain(set,i) (set[i / UINT_BITS] & (1 << i % UINT_BITS))
+#define bitset_set(set,i) (set[i / UINT_BITS] |= 1u << i % UINT_BITS)
+#define bitset_clear(set,i) (set[i / UINT_BITS] &= ~(1u << i % UINT_BITS))
+#define bitset_contain(set,i) (set[i / UINT_BITS] & (1u << i % UINT_BITS))
 #define bitset_empty(set) memset (set, 0, sizeof (unsigned int) * BITSET_UINTS)
 #define bitset_set_all(set) \
   memset (set, 255, sizeof (unsigned int) * BITSET_UINTS)

--- a/lib/regexec.c
+++ b/lib/regexec.c
@@ -1895,8 +1895,9 @@
 		  if (ent->node != node)
 		    continue;
 
-		  if (subexp_idx <= 8 * sizeof (ent->eps_reachable_subexps_map)
-		      && !(ent->eps_reachable_subexps_map & (1 << subexp_idx)))
+		  if (subexp_idx
+		      < CHAR_BIT * sizeof ent->eps_reachable_subexps_map
+		      && !(ent->eps_reachable_subexps_map & (1u << subexp_idx)))
 		    continue;
 
 		  /* Recurse trying to reach the OP_OPEN_SUBEXP and
@@ -1922,7 +1923,9 @@
 		  if (cpos == 0 && (boundaries & 2))
 		    return 0;
 
-		  ent->eps_reachable_subexps_map &= ~(1 << subexp_idx);
+		  if (subexp_idx
+		      < CHAR_BIT * sizeof ent->eps_reachable_subexps_map)
+		    ent->eps_reachable_subexps_map &= ~(1u << subexp_idx);
 	        }
 	      while (ent++->more);
 	    }
@@ -2376,8 +2379,8 @@
     {
       int node = cur_nodes->elems[node_idx];
       if (dfa->nodes[node].type == OP_OPEN_SUBEXP
-	  && dfa->nodes[node].opr.idx < (8 * sizeof (dfa->used_bkref_map))
-	  && dfa->used_bkref_map & (1 << dfa->nodes[node].opr.idx))
+	  && dfa->nodes[node].opr.idx < CHAR_BIT * sizeof dfa->used_bkref_map
+	  && dfa->used_bkref_map & (1u << dfa->nodes[node].opr.idx))
 	{
 	  err = match_ctx_add_subtop (mctx, node, str_idx);
 	  if (BE (err != REG_NOERROR, 0))
@@ -4166,7 +4169,7 @@
      A backreference does not epsilon-transition unless it is empty, so set
      to all zeros if FROM != TO.  */
   mctx->bkref_ents[mctx->nbkref_ents].eps_reachable_subexps_map
-    = (from == to ? ~0 : 0);
+    = (from == to ? -1 : 0);
 
   mctx->bkref_ents[mctx->nbkref_ents++].more = 0;
   if (mctx->max_mb_elem_len < to - from)