[XALANJ-2438] [PATCH] XSLTC ignores XPath predicates in xsl:key elements

• Type: Bug
• Status: Open
• Priority: Blocker
• Resolution: Unresolved
• Affects Version/s: The Latest Development Code
• Fix Version/s: The Latest Development Code
• Component/s: XSLTC
• Environment: Linux and Windows XP with Sun JRE 1.5.0_14, 1.5.0_15, 1.6.0_04 and 1.6.0_05
• Xalan info: PatchAvailable
• Assignee: Unassigned
• Reporter: Helge Schulz
• Created: 16/Mar/08 17:52
• Updated: 09/Oct/13 17:02

Description

The Xalan XSLT compiler (XSLTC) ignores XPath predicates in xsl:key
elements since the class 'org.apache.xalan.xsltc.compiler.Stylesheet'
was rearranged in august 2003 to reorder the compilation of top level
XSLT elements (including keys) to respect dependencies between global
XSLT variables and keys. Method 'compileTopLevel' was changed to emit
code also for key elements and not emit code calling the method generated
by 'compileBuildKeys'. For this reason the byte code for each key element
is generated twice: First time into generated method 'buildKeys' from
'compileBuildKeys' and second time into generated method 'topLevel'
from 'compileTopLevel'. Method 'buildKeys' is still necessary, because
it is called by the XSLT 'document' function, if additional input
documents are loaded later.

Unfortunately the translate method of some XPath elements expected to
be called only once and they remove sub elements while their first execution.
So all XPath predicates get lost in class 'org.apache.xalan.xsltc.compiler.FilterExpr'
and 'org.apache.xalan.xsltc.compiler.Step' by a remove operation on
the '_predicates' container while the execution from 'compileBuildKeys'.
So 'compileTopLevel' generates wrong code for all key elements containing
predicates in their XPath expressions.

The attached patch changes the 'FilterExpr' and 'Step' class to use an
index variable to determine the current predicate and to not remove them.
This patch was tested with the current Subversion version of Xalan
(last change of Xalan tree in revision 584164) and with Sun JDK 1.5.0_14,
1.5.0_15, 1.6.0_04 and 1.6.0_05.

This bug exists also in Sun JRE 1.6 (1.6.0 up to 1.6.0_05) and JRE 1.5
(since 1.5.0_12 up to 1.5.0_15) in classes
'com.sun.org.apache.xalan.internal.xsltc.compiler.FilterExpr' and
'com.sun.org.apache.xalan.internal.xsltc.compiler.Step'. The attached
test JAR file contains also patches for these versions and fixes in form
of JAR files to be installed into '../jre/lib/endorsed' directories of
Sun JRE installations. The last Sun JRE version with correct handling
of xls:key elements is 1.5.0_11.

Please add the attached test files to the Xalan test suite. I have
released them under Apache license version 2.0.

Helge Schulz - OpenSHORE.org