Remove non-matching parent elements in XSL

[BudBug]

• I need to remove all \[code\]Component\[/code\] elements and their corresponding \[code\]ComponentRef\[/code\] elements, where the \[code\]Component\[/code\] child element \[code\]File\[/code\] attribute \[code\]Source\[/code\] is NOT a \[code\]dll\[/code\] file?
• I have the evaluation function for the \[code\]Source\[/code\] string value i.e. \[code\]{substring(wix:File/@Source, string-length(wix:File/@Source) - 2)}='dll'\[/code\] returns true for \[code\]Source\[/code\] values that contain \[code\]dll\[/code\]
• But I don't know how to use the function to remove the last two \[code\]Component\[/code\] elements (with their children) as well as the corresponding last two \[code\]ComponentRef\[/code\] elements (mapped by \[code\]Id\[/code\] attribute)?

Source XML\[code\]<?xml version="1.0" encoding="utf-8"?><Wix xmlns="http://schemas.microsoft.com/wix/2006/wi"> <Fragment> <DirectoryRef Id="TARGETFOLDER"> <Component Id="cmpA733DB49D89AC9CEA2EDFAAEE51992E7" Guid="{F3412A8F-5718-45AB-9E6F-7B802BCC0EED}"> <File Source="$(var.WixSlave.TargetDir)\protobuf-net.dll" Id="fil910D6DB28382BAB5A9DF0ACBD5095ADE" KeyPath="yes" /> </Component> <Component Id="cmpF1D751B9621E283AD7BDAA8BC6997338" Guid="{20C09DBB-C8D6-43CF-A9D6-C823850F86F6}"> <File Source="$(var.WixSlave.TargetDir)\client.wyc" Id="fil7454A527FA7C3918A537EB96235C9F5F" KeyPath="yes" /> </Component> <Component Id="cmp8CDA926DD93F7CEFBF8FFF444D5828F4" Guid="{2243D9D8-C172-4FFE-AEBE-43659294E55D}"> <File Source="$(var.WixSlave.TargetDir)\protobuf-net.pdb" Id="fil3EA19C07C51C4E31D37065B3A8620713" KeyPath="yes" /> </Component> </DirectoryRef> </Fragment> <Fragment> <ComponentGroup Id="Dlls"> <ComponentRef Id="cmpA733DB49D89AC9CEA2EDFAAEE51992E7" /> <ComponentRef Id="cmpF1D751B9621E283AD7BDAA8BC6997338" /> <ComponentRef Id="cmp8CDA926DD93F7CEFBF8FFF444D5828F4" /> </ComponentGroup> </Fragment></Wix>\[/code\]Dysfunctional XSLT Stub\[code\]<?xml version="1.0" encoding="UTF-8"?><xsl:stylesheet version="1.0" xmlns="http://schemas.microsoft.com/wix/2006/wi" xmlns:wix="http://schemas.microsoft.com/wix/2006/wi" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:template match="node()|@*"> <xsl:copy> <xsl:apply-templates select="node()|@*"/> </xsl:copy> </xsl:template> <xsl:template match="wix:File[{substring(wix:File/@Source, string-length(wix:File/@Source) - 2)}!='dll']"/></xsl:stylesheet>\[/code\]

• This XSLT does not work in many ways, firstly the second \[code\]match\[/code\] complains, and I'm not sure what is wrong with the expression..
• Even if that worked, how would you always retain \[code\]DirectoryRef\[/code\] while removing the mismatching \[code\]Component\[/code\] and child \[code\]File\[/code\] elements?
• Removing the corresponding \[code\]ComponentRef\[/code\] elements is missing altogether?

Desired XML Output\[code\]<?xml version="1.0" encoding="utf-8"?><Wix xmlns="http://schemas.microsoft.com/wix/2006/wi"> <Fragment> <DirectoryRef Id="TARGETFOLDER"> <Component Id="cmpA733DB49D89AC9CEA2EDFAAEE51992E7" Guid="{F3412A8F-5718-45AB-9E6F-7B802BCC0EED}"> <File Source="$(var.WixSlave.TargetDir)\protobuf-net.dll" Id="fil910D6DB28382BAB5A9DF0ACBD5095ADE" KeyPath="yes" /> </Component> </DirectoryRef> </Fragment> <Fragment> <ComponentGroup Id="Dlls"> <ComponentRef Id="cmpA733DB49D89AC9CEA2EDFAAEE51992E7" /> </ComponentGroup> </Fragment></Wix>\[/code\]