[libxml2] add function xmlTextReaderRelaxNGValidateCtxt()

[Daniel Veillard <veillard src gnome org>]

commit 1579499025b7c614d82eba0cc6aa9cc2a788f128
Author: Noam Postavsky <npostavs users sourceforge net>
Date:   Mon Mar 19 16:08:16 2012 +0800

    add function xmlTextReaderRelaxNGValidateCtxt()
    
    Since there is xmlTextReaderSchemaValidateCtxt() it seems like there
    should be an equivalent RelaxNG function. The attached patch adds it.
    The code is essentially the same as Schema implementation, but I'm
    uncertain as to how to add things to the documentation and test suite:
    there seems to be a lot of auto-generation going on.

 include/libxml/xmlreader.h |    5 ++
 xmlreader.c                |  162 +++++++++++++++++++++++++++++++-------------
 2 files changed, 121 insertions(+), 46 deletions(-)
---
diff --git a/include/libxml/xmlreader.h b/include/libxml/xmlreader.h
index 6964482..f24e9bb 100644
--- a/include/libxml/xmlreader.h
+++ b/include/libxml/xmlreader.h
@@ -285,6 +285,11 @@ XMLPUBFUN int XMLCALL
 		    xmlTextReaderRelaxNGValidate(xmlTextReaderPtr reader,
 						 const char *rng);
 XMLPUBFUN int XMLCALL
+		    xmlTextReaderRelaxNGValidateCtxt(xmlTextReaderPtr reader,
+						 xmlRelaxNGValidCtxtPtr ctxt,
+						 int options);
+
+XMLPUBFUN int XMLCALL
 		    xmlTextReaderRelaxNGSetSchema(xmlTextReaderPtr reader,
 						 xmlRelaxNGPtr schema);
 XMLPUBFUN int XMLCALL
diff --git a/xmlreader.c b/xmlreader.c
index 97c71ab..864abf0 100644
--- a/xmlreader.c
+++ b/xmlreader.c
@@ -152,6 +152,7 @@ struct _xmlTextReader {
     /* Handling of RelaxNG validation */
     xmlRelaxNGPtr          rngSchemas;	/* The Relax NG schemas */
     xmlRelaxNGValidCtxtPtr rngValidCtxt;/* The Relax NG validation context */
+    int                    rngPreserveCtxt; /* 1 if the context was provided by the user */
     int                    rngValidErrors;/* The number of errors detected */
     xmlNodePtr             rngFullNode;	/* the node if RNG not progressive */
     /* Handling of Schemas validation */
@@ -2187,7 +2188,8 @@ xmlFreeTextReader(xmlTextReaderPtr reader) {
 	reader->rngSchemas = NULL;
     }
     if (reader->rngValidCtxt != NULL) {
-	xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
+	if (! reader->rngPreserveCtxt)
+	    xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
 	reader->rngValidCtxt = NULL;
     }
     if (reader->xsdPlug != NULL) {
@@ -4095,9 +4097,11 @@ xmlTextReaderRelaxNGSetSchema(xmlTextReaderPtr reader, xmlRelaxNGPtr schema) {
 	    reader->rngSchemas = NULL;
 	}
         if (reader->rngValidCtxt != NULL) {
-	    xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
+	    if (! reader->rngPreserveCtxt)
+		xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
 	    reader->rngValidCtxt = NULL;
         }
+	reader->rngPreserveCtxt = 0;
 	return(0);
     }
     if (reader->mode != XML_TEXTREADER_MODE_INITIAL)
@@ -4107,9 +4111,11 @@ xmlTextReaderRelaxNGSetSchema(xmlTextReaderPtr reader, xmlRelaxNGPtr schema) {
 	reader->rngSchemas = NULL;
     }
     if (reader->rngValidCtxt != NULL) {
-	xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
+	if (! reader->rngPreserveCtxt)
+	    xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
 	reader->rngValidCtxt = NULL;
     }
+    reader->rngPreserveCtxt = 0;
     reader->rngValidCtxt = xmlRelaxNGNewValidCtxt(schema);
     if (reader->rngValidCtxt == NULL)
         return(-1);
@@ -4214,67 +4220,91 @@ xmlTextReaderSetSchema(xmlTextReaderPtr reader, xmlSchemaPtr schema) {
 }
 
 /**
- * xmlTextReaderRelaxNGValidate:
+ * xmlTextReaderRelaxNGValidateInternal:
  * @reader:  the xmlTextReaderPtr used
  * @rng:  the path to a RelaxNG schema or NULL
+ * @ctxt: the RelaxNG schema validation context or NULL
+ * @options: options (not yet used)
  *
  * Use RelaxNG to validate the document as it is processed.
  * Activation is only possible before the first Read().
- * if @rng is NULL, then RelaxNG validation is deactivated.
+ * If both @rng and @ctxt are NULL, then RelaxNG validation is deactivated.
  *
  * Returns 0 in case the RelaxNG validation could be (de)activated and
- *         -1 in case of error.
+ *	   -1 in case of error.
  */
-int
-xmlTextReaderRelaxNGValidate(xmlTextReaderPtr reader, const char *rng) {
-    xmlRelaxNGParserCtxtPtr ctxt;
-
+static int
+xmlTextReaderRelaxNGValidateInternal(xmlTextReaderPtr reader,
+				     const char *rng,
+				     xmlRelaxNGValidCtxtPtr ctxt,
+				     int options ATTRIBUTE_UNUSED)
+{
     if (reader == NULL)
-        return(-1);
+	return(-1);
 
-    if (rng == NULL) {
-        if (reader->rngValidCtxt != NULL) {
+    if ((rng != NULL) && (ctxt != NULL))
+	return (-1);
+
+    if (((rng != NULL) || (ctxt != NULL)) &&
+	((reader->mode != XML_TEXTREADER_MODE_INITIAL) ||
+	 (reader->ctxt == NULL)))
+	return(-1);
+
+    /* Cleanup previous validation stuff. */
+    if (reader->rngValidCtxt != NULL) {
+	if ( !reader->rngPreserveCtxt)
 	    xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
-	    reader->rngValidCtxt = NULL;
-        }
-        if (reader->rngSchemas != NULL) {
-	    xmlRelaxNGFree(reader->rngSchemas);
-	    reader->rngSchemas = NULL;
-	}
-	return(0);
+	reader->rngValidCtxt = NULL;
     }
-    if (reader->mode != XML_TEXTREADER_MODE_INITIAL)
-	return(-1);
+    reader->rngPreserveCtxt = 0;
     if (reader->rngSchemas != NULL) {
 	xmlRelaxNGFree(reader->rngSchemas);
 	reader->rngSchemas = NULL;
     }
-    if (reader->rngValidCtxt != NULL) {
-	xmlRelaxNGFreeValidCtxt(reader->rngValidCtxt);
-	reader->rngValidCtxt = NULL;
-    }
-    ctxt = xmlRelaxNGNewParserCtxt(rng);
-    if (reader->errorFunc != NULL) {
-	xmlRelaxNGSetParserErrors(ctxt,
-			 xmlTextReaderValidityErrorRelay,
-			 xmlTextReaderValidityWarningRelay,
-			 reader);
-    }
-    if (reader->sErrorFunc != NULL) {
-	xmlRelaxNGSetValidStructuredErrors(reader->rngValidCtxt,
-			xmlTextReaderValidityStructuredRelay,
-			reader);
+
+    if ((rng == NULL) && (ctxt == NULL)) {
+	/* We just want to deactivate the validation, so get out. */
+	return(0);
     }
-    reader->rngSchemas = xmlRelaxNGParse(ctxt);
-    xmlRelaxNGFreeParserCtxt(ctxt);
-    if (reader->rngSchemas == NULL)
-        return(-1);
-    reader->rngValidCtxt = xmlRelaxNGNewValidCtxt(reader->rngSchemas);
-    if (reader->rngValidCtxt == NULL) {
-	xmlRelaxNGFree(reader->rngSchemas);
-	reader->rngSchemas = NULL;
-        return(-1);
+
+
+    if (rng != NULL) {
+	xmlRelaxNGParserCtxtPtr pctxt;
+	/* Parse the schema and create validation environment. */
+
+	pctxt = xmlRelaxNGNewParserCtxt(rng);
+	if (reader->errorFunc != NULL) {
+	    xmlRelaxNGSetParserErrors(pctxt,
+		xmlTextReaderValidityErrorRelay,
+		xmlTextReaderValidityWarningRelay,
+		reader);
+	}
+	if (reader->sErrorFunc != NULL) {
+	    xmlRelaxNGSetValidStructuredErrors(reader->rngValidCtxt,
+		xmlTextReaderValidityStructuredRelay,
+		reader);
+	}
+	reader->rngSchemas = xmlRelaxNGParse(pctxt);
+	xmlRelaxNGFreeParserCtxt(pctxt);
+	if (reader->rngSchemas == NULL)
+	    return(-1);
+	reader->rngValidCtxt = xmlRelaxNGNewValidCtxt(reader->rngSchemas);
+	if (reader->rngValidCtxt == NULL) {
+	    xmlRelaxNGFree(reader->rngSchemas);
+	    reader->rngSchemas = NULL;
+	    return(-1);
+	}
+    } else {
+	/* Use the given validation context. */
+	reader->rngValidCtxt = ctxt;
+	reader->rngPreserveCtxt = 1;
     }
+    /*
+    * Redirect the validation context's error channels to use
+    * the reader channels.
+    * TODO: In case the user provides the validation context we
+    *	could make this redirection optional.
+    */
     if (reader->errorFunc != NULL) {
 	xmlRelaxNGSetValidErrors(reader->rngValidCtxt,
 			 xmlTextReaderValidityErrorRelay,
@@ -4447,6 +4477,46 @@ xmlTextReaderSchemaValidate(xmlTextReaderPtr reader, const char *xsd)
 {
     return(xmlTextReaderSchemaValidateInternal(reader, xsd, NULL, 0));
 }
+
+/**
+ * xmlTextReaderRelaxNGValidateCtxt:
+ * @reader:  the xmlTextReaderPtr used
+ * @ctxt: the RelaxNG schema validation context or NULL
+ * @options: options (not used yet)
+ *
+ * Use RelaxNG schema context to validate the document as it is processed.
+ * Activation is only possible before the first Read().
+ * If @ctxt is NULL, then RelaxNG schema validation is deactivated.
+ *
+ * Returns 0 in case the schemas validation could be (de)activated and
+ *         -1 in case of error.
+ */
+int
+xmlTextReaderRelaxNGValidateCtxt(xmlTextReaderPtr reader,
+				 xmlRelaxNGValidCtxtPtr ctxt,
+				 int options)
+{
+    return(xmlTextReaderRelaxNGValidateInternal(reader, NULL, ctxt, options));
+}
+
+/**
+ * xmlTextReaderRelaxNGValidate:
+ * @reader:  the xmlTextReaderPtr used
+ * @rng:  the path to a RelaxNG schema or NULL
+ *
+ * Use RelaxNG schema to validate the document as it is processed.
+ * Activation is only possible before the first Read().
+ * If @rng is NULL, then RelaxNG schema validation is deactivated.
+ *
+ * Returns 0 in case the schemas validation could be (de)activated and
+ *         -1 in case of error.
+ */
+int
+xmlTextReaderRelaxNGValidate(xmlTextReaderPtr reader, const char *rng)
+{
+    return(xmlTextReaderRelaxNGValidateInternal(reader, rng, NULL, 0));
+}
+
 #endif
 
 /**