xmlValidatePopElement() can return invalid value (-1)

Covered by:  test/VC/ElementValid5

This only affects XML Reader API with LIBXML_REGEXP_ENABLED and
LIBXML_VALID_ENABLED turned on.

* result/VC/ElementValid5.rdr:
- Update result to add missing error message.

* python/tests/reader2.py:
* result/VC/ElementValid6.rdr:
* result/VC/ElementValid7.rdr:
* result/valid/781333.xml.err.rdr:
- Update result to fix grammar issue.

* valid.c:
(xmlValidatePopElement):
- Check return value of xmlRegExecPushString() to handle -1, and
  assign 'ret = 0;' to return 0 from xmlValidatePopElement().
  This change affects xmlTextReaderValidatePop() from
  xmlreader.c.
- Fix grammar of error message by changing 'child' to
  'children'.

6 files changed, 10 insertions, 6 deletions

diff --git a/python/tests/reader2.py b/python/tests/reader2.py
index 802d848d..9d3b7065 100755
--- a/python/tests/reader2.py
+++ b/python/tests/reader2.py
@@ -41,7 +41,7 @@ value
 """{0}/781333.xml:4: element a: validity error : Element a content does not follow the DTD, expecting ( ..., got 
 <a/>
     ^
-{0}/781333.xml:5: element a: validity error : Element a content does not follow the DTD, Expecting more child
+{0}/781333.xml:5: element a: validity error : Element a content does not follow the DTD, Expecting more children
 
 ^
 """.format(dir_prefix),
diff --git a/result/VC/ElementValid5.rdr b/result/VC/ElementValid5.rdr
index 899d7591..91eef9c6 100644
--- a/result/VC/ElementValid5.rdr
+++ b/result/VC/ElementValid5.rdr
@@ -4,3 +4,6 @@
 ./test/VC/ElementValid5:8: element doc: validity error : Element doc content does not follow the DTD, Misplaced b
 
 ^
+./test/VC/ElementValid5:8: element doc: validity error : Element doc content does not follow the DTD, Expecting more children
+
+^
diff --git a/result/VC/ElementValid6.rdr b/result/VC/ElementValid6.rdr
index aeafd6be..3b51d1a1 100644
--- a/result/VC/ElementValid6.rdr
+++ b/result/VC/ElementValid6.rdr
@@ -1,6 +1,6 @@
 ./test/VC/ElementValid6:7: element doc: validity error : Element doc content does not follow the DTD, expecting (a , b? , c+)?, got (a b)
 <doc><a/><b>lacks c</b></doc>
                              ^
-./test/VC/ElementValid6:8: element doc: validity error : Element doc content does not follow the DTD, Expecting more child
+./test/VC/ElementValid6:8: element doc: validity error : Element doc content does not follow the DTD, Expecting more children
 
 ^
diff --git a/result/VC/ElementValid7.rdr b/result/VC/ElementValid7.rdr
index f001fd21..ecafd1db 100644
--- a/result/VC/ElementValid7.rdr
+++ b/result/VC/ElementValid7.rdr
@@ -1,6 +1,6 @@
 ./test/VC/ElementValid7:7: element doc: validity error : Element doc content does not follow the DTD, expecting ((a | b)* , c+ , a , b? , c , a?), got (a b a c c a)
 <doc><a/><b/><a/><c/><c/><a/></doc>
                                    ^
-./test/VC/ElementValid7:8: element doc: validity error : Element doc content does not follow the DTD, Expecting more child
+./test/VC/ElementValid7:8: element doc: validity error : Element doc content does not follow the DTD, Expecting more children
 
 ^
diff --git a/result/valid/781333.xml.err.rdr b/result/valid/781333.xml.err.rdr
index 5ff56992..dd9df08f 100644
--- a/result/valid/781333.xml.err.rdr
+++ b/result/valid/781333.xml.err.rdr
@@ -1,6 +1,6 @@
 ./test/valid/781333.xml:4: element a: validity error : Element a content does not follow the DTD, expecting ( ..., got 
 <a/>
     ^
-./test/valid/781333.xml:5: element a: validity error : Element a content does not follow the DTD, Expecting more child
+./test/valid/781333.xml:5: element a: validity error : Element a content does not follow the DTD, Expecting more children
 
 ^
diff --git a/valid.c b/valid.c
index 773f125e..479fa628 100644
--- a/valid.c
+++ b/valid.c
@@ -5999,11 +5999,12 @@ xmlValidatePopElement(xmlValidCtxtPtr ctxt, xmlDocPtr doc ATTRIBUTE_UNUSED,
 	    if (elemDecl->etype == XML_ELEMENT_TYPE_ELEMENT) {
 		if (state->exec != NULL) {
 		    ret = xmlRegExecPushString(state->exec, NULL, NULL);
-		    if (ret == 0) {
+		    if (ret <= 0) {
 			xmlErrValidNode(ctxt, state->node,
 			                XML_DTD_CONTENT_MODEL,
-	   "Element %s content does not follow the DTD, Expecting more child\n",
+	   "Element %s content does not follow the DTD, Expecting more children\n",
 			       state->node->name, NULL,NULL);
+			ret = 0;
 		    } else {
 			/*
 			 * previous validation errors should not generate