tree: Fix handling of empty strings in xmlNodeParseContent

We shouldn't create an empty text node to match the old behavior.

Fixes #759.

Author: nwellnhof

testparser.c

@@ -12,6 +12,21 @@
 
 #include <string.h>
 
+static int
+testNewDocNode(void) {
+    xmlNodePtr node;
+    int err = 0;
+
+    node = xmlNewDocNode(NULL, NULL, BAD_CAST "c", BAD_CAST "");
+    if (node->children != NULL) {
+        fprintf(stderr, "empty node has children\n");
+        err = 1;
+    }
+    xmlFreeNode(node);
+
+    return err;
+}
+
 static int
 testStandaloneWithEncoding(void) {
     xmlDocPtr doc;
@@ -521,6 +536,7 @@ int
 main(void) {
     int err = 0;
 
+    err |= testNewDocNode();
     err |= testStandaloneWithEncoding();
     err |= testUnsupportedEncoding();
     err |= testNodeGetContent();

tree.c

@@ -1213,7 +1213,7 @@ xmlNodeParseContentInternal(const xmlDoc *doc, xmlNodePtr parent,
     else
         remaining = len;
 
-    if (value == NULL)
+    if ((value == NULL) || (value[0] == 0))
         goto done;
 
     cur = value;