Update.

	* posix/bug-regex11.c: Add some more tests which fail so far.
	Disable them.  Patch by Paolo Bonzini <bonzini@gnu.org>.

2003-10-05  Paolo Bonzini  <bonzini@gnu.org>

	* posix/bug-regex11.c: Add more backreference-related test cases.
	(main): Show the failing regex in the error messages.
	* posix/regexec.c (check_dst_limits_calc_pos):
	Simplify some nested conditionals.  Replace if's with a switch
	statement.
	(check_dst_limits_calc_pos <TYPE_BKREF>): Rename parameter NODE to
	FROM_NODE, it shadows a local variable; don't recurse if FROM_NODE
	does not change in the recursive invocation, fixing an infinite loop
	in the ()\1*\1* regex.
	(sift_states_backward): Fix function comment.
	* posix/regcomp.c (calc_epsdest): Add an assertion.

2003-10-06  Ulrich Drepper  <drepper@redhat.com>

2 files changed, 82 insertions, 31 deletions

diff --git a/posix/bug-regex11.c b/posix/bug-regex11.c
index 40fd7c2..c7a8b65 100644
--- a/posix/bug-regex11.c
+++ b/posix/bug-regex11.c
@@ -35,6 +35,7 @@ struct
   /* Test for newline handling in regex.  */
   { "[^~]*~", "\nx~y", 0, 2, { { 0, 3 }, { -1, -1 } } },
   /* Other tests.  */
+  { "a(.*)b", "a b", REG_EXTENDED, 2, { { 0, 3 }, { 1, 2 } } },
   { ".*|\\([KIO]\\)\\([^|]*\\).*|?[KIO]", "10~.~|P|K0|I10|O16|?KSb", 0, 3,
     { { 0, 21 }, { 15, 16 }, { 16, 18 } } },
   { ".*|\\([KIO]\\)\\([^|]*\\).*|?\\1", "10~.~|P|K0|I10|O16|?KSb", 0, 3,
@@ -52,6 +53,18 @@ struct
   /* Here ^ cannot be treated as an anchor according to POSIX.  */
   { "(^|foo)bar", "(^|foo)bar", 0, 2, { { 0, 10 }, { -1, -1 } } },
   { "(foo|^)bar", "(foo|^)bar", 0, 2, { { 0, 10 }, { -1, -1 } } },
+  /* More tests on backreferences.  */
+  { "()\\1*\\1*", "", REG_EXTENDED, 2, { { 0, 0 }, { 0, 0 } } },
+  { "([0-9]).*\\1(a*)", "7;7a6", REG_EXTENDED, 3, { { 0, 4 }, { 0, 1 }, { 3, 4 } } },
+  { "([0-9]).*\\1(a*)", "7;7a", REG_EXTENDED, 3, { { 0, 4 }, { 0, 1 }, { 3, 4 } } },
+#if 0
+  /* XXX This test seems wrong. --drepper */
+  { "()(b)\\1c\\2", "bcb", REG_EXTENDED, 3, { { 0, 3 }, { 0, 0 }, { 1, 2 } } },
+
+  /* XXX Not used since they fail so far.  */
+  { "(b())\\2\\1", "bbbb", REG_EXTENDED, 3, { { 0, 2 }, { 0, 1 }, { 1, 1 } } },
+  { "(bb())\\2\\1", "bbbb", REG_EXTENDED, 3, { { 0, 4 }, { 0, 2 }, { 2, 2 } } },
+#endif
 };
 
 int
@@ -71,14 +84,14 @@ main (void)
 	{
 	  char buf[500];
 	  regerror (n, &re, buf, sizeof (buf));
-	  printf ("regcomp %zd failed: %s\n", i, buf);
+	  printf ("%s: regcomp %zd failed: %s\n", tests[i].pattern, i, buf);
 	  ret = 1;
 	  continue;
 	}
 
       if (regexec (&re, tests[i].string, tests[i].nmatch, rm, 0))
 	{
-	  printf ("regexec %zd failed\n", i);
+	  printf ("%s: regexec %zd failed\n", tests[i].pattern, i);
 	  ret = 1;
 	  regfree (&re);
 	  continue;
@@ -90,8 +103,8 @@ main (void)
 	  {
 	    if (tests[i].rm[n].rm_so == -1 && tests[i].rm[n].rm_eo == -1)
 	      break;
-	    printf ("regexec match failure rm[%d] %d..%d\n",
-		    n, rm[n].rm_so, rm[n].rm_eo);
+	    printf ("%s: regexec %zd match failure rm[%d] %d..%d\n",
+		    tests[i].pattern, i, n, rm[n].rm_so, rm[n].rm_eo);
 	    ret = 1;
 	    break;
 	  }
diff --git a/posix/regexec.c b/posix/regexec.c
index 39a27d2..3cd8bea 100644
--- a/posix/regexec.c
+++ b/posix/regexec.c
@@ -1387,7 +1387,7 @@ update_regs (dfa, pmatch, cur_node, cur_idx, nmatch)
 	   away the node `a'.
 	ii. If 'b' is in the STATE_LOG[STR_IDX+strlen('s')] but 'b' is
 	    throwed away, we throw away the node `a'.
-     3. When 0 <= STR_IDX < n and 'a' epsilon transit to 'b':
+     3. When 0 <= STR_IDX < MATCH_LAST and 'a' epsilon transit to 'b':
 	i. If 'b' isn't in the STATE_LOG[STR_IDX], we throw away the
 	   node `a'.
 	ii. If 'b' is in the STATE_LOG[STR_IDX] but 'b' is throwed away,
@@ -1724,60 +1724,98 @@ check_dst_limits (dfa, limits, mctx, dst_node, dst_idx, src_node, src_idx)
 }
 
 static int
-check_dst_limits_calc_pos (dfa, mctx, limit, eclosures, subexp_idx, node,
+check_dst_limits_calc_pos (dfa, mctx, limit, eclosures, subexp_idx, from_node,
 			   str_idx)
      re_dfa_t *dfa;
      re_match_context_t *mctx;
      re_node_set *eclosures;
-     int limit, subexp_idx, node, str_idx;
+     int limit, subexp_idx, from_node, str_idx;
 {
   struct re_backref_cache_entry *lim = mctx->bkref_ents + limit;
-  int pos = (str_idx < lim->subexp_from ? -1
-	     : (lim->subexp_to < str_idx ? 1 : 0));
-  if (pos == 0
-      && (str_idx == lim->subexp_from || str_idx == lim->subexp_to))
-    {
       int node_idx;
+
+  /* If we are outside the range of the subexpression, return -1 or 1.  */
+  if (str_idx < lim->subexp_from)
+    return -1;
+
+  if (lim->subexp_to < str_idx)
+    return 1;
+
+  /* If we are within the subexpression, return 0.  */
+  if (str_idx != lim->subexp_from && str_idx != lim->subexp_to)
+    return 0;
+
+  /* Else, we are on the boundary: examine the nodes on the epsilon
+     closure.  */
       for (node_idx = 0; node_idx < eclosures->nelem; ++node_idx)
 	{
 	  int node = eclosures->elems[node_idx];
-	  re_token_type_t type= dfa->nodes[node].type;
-	  if (type == OP_BACK_REF)
+      switch (dfa->nodes[node].type)
+	{
+	case OP_BACK_REF:
 	    {
 	      int bi = search_cur_bkref_entry (mctx, str_idx);
 	      for (; bi < mctx->nbkref_ents; ++bi)
 		{
 		  struct re_backref_cache_entry *ent = mctx->bkref_ents + bi;
+		int dst, cpos;
+		
+		/* If this backreference goes beyond the point we're
+		   examining, don't go any further.  */
 		  if (ent->str_idx > str_idx)
 		    break;
-		  if (ent->node == node && ent->subexp_from == ent->subexp_to)
-		    {
-		      int cpos, dst;
+
+		if (ent->node != node || ent->subexp_from != ent->subexp_to)
+		  continue;
+
+		/* Recurse trying to reach the OP_OPEN_SUBEXP and
+		   OP_CLOSE_SUBEXP cases below.  But, if the
+		   destination node is the same node as the source
+		   node, don't recurse because it would cause an
+		   infinite loop: a regex that exhibits this behavior
+		   is ()\1*\1*  */
 		      dst = dfa->edests[node].elems[0];
+		if (dst == from_node)
+		  {
+		    if (str_idx == lim->subexp_from)
+		      return -1;
+		    else /* if (str_idx == lim->subexp_to) */
+		      return 0;
+		  }
+
 		      cpos = check_dst_limits_calc_pos (dfa, mctx, limit,
 							dfa->eclosures + dst,
 							subexp_idx, dst,
 							str_idx);
-		      if ((str_idx == lim->subexp_from && cpos == -1)
-			  || (str_idx == lim->subexp_to && cpos == 0))
-			return cpos;
-		    }
-		}
+
+		if (cpos == -1 && str_idx == lim->subexp_from)
+		  return -1;
+
+		if (cpos == 0 /* && str_idx == lim->lim->subexp_to */)
+		  return 0;
 	    }
-	  if (type == OP_OPEN_SUBEXP && subexp_idx == dfa->nodes[node].opr.idx
-	      && str_idx == lim->subexp_from)
-	    {
-	      pos = -1;
 	      break;
 	    }
-	  if (type == OP_CLOSE_SUBEXP && subexp_idx == dfa->nodes[node].opr.idx
-	      && str_idx == lim->subexp_to)
+	  
+	case OP_OPEN_SUBEXP:
+	  if (str_idx == lim->subexp_from && subexp_idx == dfa->nodes[node].opr.idx)
+	    return -1;
+	  break;
+	  
+	case OP_CLOSE_SUBEXP:
+	  if (str_idx == lim->subexp_to && subexp_idx == dfa->nodes[node].opr.idx)
+	    return 0;
+	  break;
+
+	default:
 	    break;
 	}
-      if (node_idx == eclosures->nelem && str_idx == lim->subexp_to)
-	pos = 1;
     }
-  return pos;
+
+  if (str_idx == lim->subexp_to)
+    return 1;
+  else
+    return 0;
 }
 
 /* Check the limitations of sub expressions LIMITS, and remove the nodes