[libxml2] Fix an error with regexp on nullable counted char transition

[Daniel Veillard <veillard src gnome org>]

commit 34b350048d1ee97c4f42dd6729a77b3f36753b3a
Author: Daniel Veillard <veillard redhat com>
Date:   Mon May 9 09:28:38 2016 +0800

    Fix an error with regexp on nullable counted char transition
    
    This is the first of the two issues raised by Pete Cordell
    in https://mail.gnome.org/archives/xml/2016-April/msg00030.html

 xmlregexp.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)
---
diff --git a/xmlregexp.c b/xmlregexp.c
index 4e65f6b..727fef4 100644
--- a/xmlregexp.c
+++ b/xmlregexp.c
@@ -1544,6 +1544,7 @@ static int
 xmlFAGenerateTransitions(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr from,
                         xmlRegStatePtr to, xmlRegAtomPtr atom) {
     xmlRegStatePtr end;
+    int nullable = 0;
 
     if (atom == NULL) {
        ERROR("genrate transition: atom == NULL");
@@ -1730,6 +1731,13 @@ xmlFAGenerateTransitions(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr from,
     if (xmlRegAtomPush(ctxt, atom) < 0) {
        return(-1);
     }
+    if ((atom->quant == XML_REGEXP_QUANT_RANGE) &&
+        (atom->min == 0) && (atom->max > 0)) {
+       nullable = 1;
+       atom->min = 1;
+        if (atom->max == 1)
+           atom->quant = XML_REGEXP_QUANT_OPT;
+    }
     xmlRegStateAddTrans(ctxt, from, atom, to, -1, -1);
     ctxt->state = end;
     switch (atom->quant) {
@@ -1747,11 +1755,8 @@ xmlFAGenerateTransitions(xmlRegParserCtxtPtr ctxt, xmlRegStatePtr from,
            xmlRegStateAddTrans(ctxt, to, atom, to, -1, -1);
            break;
        case XML_REGEXP_QUANT_RANGE:
-#if DV_test
-           if (atom->min == 0) {
+           if (nullable)
                xmlFAGenerateEpsilonTransition(ctxt, from, to);
-           }
-#endif
            break;
        default:
            break;