Fix KotlinVersionsTest, use SAX parser instead of DOM

compiler/tests/org/jetbrains/kotlin/util/KotlinVersionsTest.kt

@@ -24,10 +24,11 @@ import org.jetbrains.kotlin.config.LanguageVersion
 import org.jetbrains.kotlin.test.testFramework.KtUsefulTestCase
 import org.jetbrains.kotlin.utils.addIfNotNull
 import org.junit.Assert
-import org.w3c.dom.Element
+import org.xml.sax.Attributes
+import org.xml.sax.helpers.DefaultHandler
 import java.io.File
 import java.util.*
-import javax.xml.parsers.DocumentBuilderFactory
+import javax.xml.parsers.SAXParserFactory
 
 class KotlinVersionsTest : KtUsefulTestCase() {
     fun testVersionsAreConsistent() {
@@ -72,13 +73,13 @@ class KotlinVersionsTest : KtUsefulTestCase() {
         )
 
         versions.add(
-                loadValueFromPomXml("libraries/pom.xml", listOf("properties", "kotlin.language.version"))
+                loadValueFromPomXml("libraries/pom.xml", listOf("project", "properties", "kotlin.language.version"))
                         ?.toVersion("kotlin.language.version in pom.xml")
                 ?: error("No kotlin.language.version in libraries/pom.xml")
         )
 
         versions.add(
-                loadValueFromPomXml("libraries/pom.xml", listOf("version"))
+                loadValueFromPomXml("libraries/pom.xml", listOf("project", "version"))
                         ?.toVersion("version in pom.xml")
                 ?: error("No version in libraries/pom.xml")
         )
@@ -102,8 +103,8 @@ class KotlinVersionsTest : KtUsefulTestCase() {
 
         FileUtil.processFilesRecursively(File("libraries"), Processor { file ->
             if (file.name == "pom.xml") {
-                if (loadValueFromPomXml(file.path, listOf("parent", "artifactId")) == "kotlin-project") {
+                if (loadValueFromPomXml(file.path, listOf("project", "parent", "artifactId")) == "kotlin-project") {
-                    val version = loadValueFromPomXml(file.path, listOf("version"))
+                    val version = loadValueFromPomXml(file.path, listOf("project", "parent", "version"))
                                   ?: error("No version found in pom.xml at $file")
                     poms.add(Pom(file.path, version))
                 }
@@ -127,12 +128,29 @@ class KotlinVersionsTest : KtUsefulTestCase() {
     private fun loadValueFromPomXml(filePath: String, query: List<String>): String? {
         assert(filePath.endsWith("pom.xml")) { filePath }
 
-        val docBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder()
+        var result: String? = null
-        val input = docBuilder.parse(File(filePath).inputStream())
 
-        return query.fold(input.documentElement) { element, tagName ->
+        SAXParserFactory.newInstance().newSAXParser().parse(File(filePath), object : DefaultHandler() {
-            element?.getElementsByTagName(tagName)?.item(0) as? Element
+            val currentPath = mutableListOf<String>()
-        }?.textContent
+
+            override fun startElement(uri: String, localName: String, qName: String, attributes: Attributes) {
+                currentPath.add(qName)
+            }
+
+            override fun endElement(uri: String, localName: String, qName: String) {
+                assert(currentPath.lastOrNull() == qName) { "Invalid XML at $filePath: mismatched tag '$qName'" }
+                currentPath.removeAt(currentPath.lastIndex)
+            }
+
+            override fun characters(ch: CharArray, start: Int, length: Int) {
+                if (currentPath == query) {
+                    assert(result == null) { "More than one value found for $query in $filePath" }
+                    result = String(ch, start, length).trim()
+                }
+            }
+        })
+
+        return result
     }
 
     private fun Collection<Any>.areEqual(): Boolean = all(first()::equals)