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authorUlrich Drepper <drepper@redhat.com>2005-02-22 05:07:20 +0000
committerUlrich Drepper <drepper@redhat.com>2005-02-22 05:07:20 +0000
commit744eb12b7b0aa4ea0543e8dfd21b49bb5309bf93 (patch)
tree1070955160a5ef90fe2144ded572b6147e91501f /posix/regcomp.c
parente13e33e279e193191e06811cb7ae3518d7acad1a (diff)
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* posix/regcomp.c (lower_subexp): Do not optimize empty
	subexpressions even with REG_NOSUB.
	* posix/rxspencer/tests: Add a previously failing testcase.
Diffstat (limited to 'posix/regcomp.c')
-rw-r--r--posix/regcomp.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/posix/regcomp.c b/posix/regcomp.c
index 1a5f7952c3..a7112cffdd 100644
--- a/posix/regcomp.c
+++ b/posix/regcomp.c
@@ -1321,6 +1321,11 @@ lower_subexp (err, preg, node)
   bin_tree_t *op, *cls, *tree1, *tree;
 
   if (preg->no_sub
+      /* We do not optimize empty subexpressions, because otherwise we may
+	 have bad CONCAT nodes with NULL children.  This is obviously not
+	 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))))
     return node->left;