XPath: Fix optimization bug with //name[last()]

The actual condition for the optimization is invariance from context list
-- this includes both position() and last().

Instead of splitting the posinv concept just include last() into
non-posinv expressions - this requires sorting for boolean predicates that
depend on last() and do not depend on position(). These cases should be
very rare.

git-svn-id: https://pugixml.googlecode.com/svn/trunk@1060 99668b35-9821-0410-8761-19e4c4f06640
This commit is contained in:
Arseny Kapoulkine 2014-10-15 06:05:49 +00:00
parent 87d4f03187
commit 883031fb45
2 changed files with 7 additions and 0 deletions

View File

@ -9621,6 +9621,7 @@ PUGI__NS_BEGIN
switch (_type)
{
case ast_func_position:
case ast_func_last:
return false;
case ast_string_constant:

View File

@ -531,6 +531,12 @@ TEST_XML(xpath_paths_descendant_optimize, "<node><para><para/><para/><para><para
CHECK_XPATH_NODESET(doc, STR("/descendant-or-self::node()[3]/child::para")) % 4 % 5 % 6;
}
TEST_XML(xpath_paths_descendant_optimize_last, "<node><para><para/><para/><para><para/></para></para><para/></node>")
{
CHECK_XPATH_NODESET(doc, STR("//para[last()]")) % 6 % 7 % 8;
CHECK_XPATH_NODESET(doc, STR("//para[last() = 1]")) % 7;
}
TEST_XML(xpath_paths_precision, "<node><para/><para/><para/><para/><para/></node>")
{
CHECK_XPATH_NODESET(doc, STR("//para[1]")) % 3;