applied patch from Youri Golovanov fixing bug #316338 and adding a couple

* xmlregexp.c: applied patch from Youri Golovanov fixing bug
  #316338 and adding a couple of optimizations in the regexp
  compilation engine.
* test/regexp/bug316338 result/regexp/bug316338: added regression
  tests based on the examples provided in the bug report.
Daniel

1 files changed, 34 insertions, 18 deletions

diff --git a/xmlregexp.c b/xmlregexp.c
index 8d7ee97f..58f480da 100644
--- a/xmlregexp.c
+++ b/xmlregexp.c
@@ -1479,7 +1479,13 @@ xmlFAGenerateTransitions(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr from,
 	switch (atom->quant) {
 	    case XML_REGEXP_QUANT_OPT:
 		atom->quant = XML_REGEXP_QUANT_ONCE;
-		xmlFAGenerateEpsilonTransition(ctxt, atom->start, atom->stop);
+		/*
+		 * transition done to the state after end of atom.
+		 *      1. set transition from atom start to new state
+		 *      2. set transition from atom end to this state. 
+		 */
+		xmlFAGenerateEpsilonTransition(ctxt, atom->start, 0);
+		xmlFAGenerateEpsilonTransition(ctxt, atom->stop, ctxt->state);
 		break;
 	    case XML_REGEXP_QUANT_MULT:
 		atom->quant = XML_REGEXP_QUANT_ONCE;
@@ -1522,8 +1528,6 @@ xmlFAGenerateTransitions(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr from,
 		atom->min = 0;
 		atom->max = 0;
 		atom->quant = XML_REGEXP_QUANT_ONCE;
-		xmlFAGenerateCountedEpsilonTransition(ctxt, atom->stop,
-			                              atom->start, counter);
 		if (to != NULL) {
 		    newstate = to;
 		} else {
@@ -1533,6 +1537,13 @@ xmlFAGenerateTransitions(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr from,
 		ctxt->state = newstate;
 		xmlFAGenerateCountedTransition(ctxt, atom->stop,
 			                       newstate, counter);
+                
+                /*
+		 * first check count and if OK jump forward; 
+                 * if checking fail increment count and jump back
+		 */
+		xmlFAGenerateCountedEpsilonTransition(ctxt, atom->stop,
+			                              atom->start, counter);
 	    }
 	    default:
 		break;
@@ -4299,6 +4310,15 @@ xmlRegExecPushChar(xmlRegExecCtxtPtr exec, int UCS) {
 		if (exec->state->nbTrans > exec->transno + 1) {
 		    xmlFARegExecSave(exec);
 		}
+		/*
+		 * restart count for expressions like this ((abc){2})*
+		 */
+		if (trans->count >= 0) {
+#ifdef DEBUG_REGEXP_EXEC
+		    printf("Reset count %d\n", trans->count);
+#endif
+		    exec->counts[trans->count] = 0;
+		}
 		if (trans->counter >= 0) {
 #ifdef DEBUG_REGEXP_EXEC
 		    printf("Increasing count %d\n", trans->counter);
@@ -5112,19 +5132,23 @@ xmlFAParsePiece(xmlRegParserCtxtPtr ctxt) {
 /**
  * xmlFAParseBranch:
  * @ctxt:  a regexp parser context
+ * @to: optional target to the end of the branch
+ *
+ * @to is used to optimize by removing duplicate path in automata
+ * in expressions like (a|b)(c|d)
  *
  * [2]   branch   ::=   piece*
- 8
  */
 static int
-xmlFAParseBranch(xmlRegParserCtxtPtr ctxt) {
+xmlFAParseBranch(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr to) {
     xmlRegStatePtr previous;
     int ret;
 
     previous = ctxt->state;
     ret = xmlFAParsePiece(ctxt);
     if (ret != 0) {
-	if (xmlFAGenerateTransitions(ctxt, previous, NULL, ctxt->atom) < 0)
+	if (xmlFAGenerateTransitions(ctxt, previous, 
+	        (CUR=='|' || CUR==')') ? to : NULL, ctxt->atom) < 0)
 	    return(-1);
 	previous = ctxt->state;
 	ctxt->atom = NULL;
@@ -5132,8 +5156,8 @@ xmlFAParseBranch(xmlRegParserCtxtPtr ctxt) {
     while ((ret != 0) && (ctxt->error == 0)) {
 	ret = xmlFAParsePiece(ctxt);
 	if (ret != 0) {
-	    if (xmlFAGenerateTransitions(ctxt, previous, NULL,
-					 ctxt->atom) < 0)
+	    if (xmlFAGenerateTransitions(ctxt, previous, 
+	            (CUR=='|' || CUR==')') ? to : NULL, ctxt->atom) < 0)
 		    return(-1);
 	    previous = ctxt->state;
 	    ctxt->atom = NULL;
@@ -5156,7 +5180,7 @@ xmlFAParseRegExp(xmlRegParserCtxtPtr ctxt, int top) {
     /* if not top start should have been generated by an epsilon trans */
     start = ctxt->state;
     ctxt->end = NULL;
-    xmlFAParseBranch(ctxt);
+    xmlFAParseBranch(ctxt, NULL);
     if (top) {
 #ifdef DEBUG_REGEXP_GRAPH
 	printf("State %d is final\n", ctxt->state->no);
@@ -5172,15 +5196,7 @@ xmlFAParseRegExp(xmlRegParserCtxtPtr ctxt, int top) {
 	NEXT;
 	ctxt->state = start;
 	ctxt->end = NULL;
-	xmlFAParseBranch(ctxt);
-	if (top) {
-	    ctxt->state->type = XML_REGEXP_FINAL_STATE;
-#ifdef DEBUG_REGEXP_GRAPH
-	    printf("State %d is final\n", ctxt->state->no);
-#endif
-	} else {
-	    xmlFAGenerateEpsilonTransition(ctxt, ctxt->state, end);
-	}
+	xmlFAParseBranch(ctxt, end);
     }
     if (!top) {
 	ctxt->state = end;