Documentation fixes
Fixes bug 347465, bug 599433, bug 624550, bug 698253.
diff --git a/xmlreader.c b/xmlreader.c
index f285790..34c4c6b 100644
--- a/xmlreader.c
+++ b/xmlreader.c
@@ -3982,7 +3982,7 @@
* pattern. The caller must also use xmlTextReaderCurrentDoc() to
* keep an handle on the resulting document once parsing has finished
*
- * Returns a positive number in case of success and -1 in case of error
+ * Returns a non-negative number in case of success and -1 in case of error
*/
int
xmlTextReaderPreservePattern(xmlTextReaderPtr reader, const xmlChar *pattern,