The XPATH implementation was not handling correctly the XPATH
production #19
(http://www.w3.org/TR/1999/REC-xpath-19991116/#node-sets),
namely
PathExpr ::= | FilterExpr '/' RelativeLocationPath
| FilterExpr '//' RelativeLocationPath
It was lacking context for the RelativeLocationPath and it was just
ignoring the second slash instead of treating it as a different axis
specifier.
Fixed the above two problems and added a test case.
Problem: a byte behind the end of input string was read
in case of a broken XML not having a quote or doublequote
character closing a string value.
Fix: changing condition not to read behind the end of input string
@ mysql-test/r/xml.result
@ mysql-test/t/xml.test
Adding tests
@ strings/xml.c
When checking if the closing quote/doublequote was found,
using p->cur[0] us unsafe, as p->cur can point to the byte after the value.
Comparing p->cur to p->beg instead.
Problem: the scanner function tested for strings "<
