Fix multipart resolution + test nits

Author: andreaschat-db

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/DataSourceV2Utils.scala

@@ -142,7 +142,7 @@ private[sql] object DataSourceV2Utils extends Logging {
         DataSource.lookupDataSourceV2(nameParts.head, conf).flatMap {
           case sco: SupportsCatalogOptions =>
             val optionsWithPath = getOptionsWithPaths(
-              CaseInsensitiveMap(Map.empty), nameParts.tail.mkString("."))
+              CaseInsensitiveMap(Map.empty), nameParts.tail: _*)
             val dsOptions = buildDsOptions(sco, conf, optionsWithPath)
             Some(extractCatalogAndIdentifier(sco, dsOptions))
           case _ => None

sql/core/src/test/scala/org/apache/spark/sql/connector/PathBasedTableSuite.scala

@@ -48,9 +48,7 @@ class PathBasedTableSuite extends QueryTest with SharedSparkSession {
   }
 
   override def afterEach(): Unit = {
-    // SharedSparkSession reuses one SparkSession across tests. `reset()` drops registered
-    // non-session catalogs (including pathformat_cat), so the next test starts with a
-    // fresh InMemoryTableCatalog instance.
+    // Start each test starts with a fresh InMemoryTableCatalog instance.
     spark.sessionState.catalogManager.reset()
     spark.conf.unset(s"spark.sql.catalog.${FakePathBasedSource.CATALOG_NAME}")
     super.afterEach()
@@ -113,7 +111,7 @@ class PathBasedTableSuite extends QueryTest with SharedSparkSession {
     }
   }
 
-  test("regression: v1 file format direct query still resolves") {
+  test("v1 file format direct query still resolves") {
     withTempDir { dir =>
       val path = new java.io.File(dir, "p.parquet").getCanonicalPath
       Seq((1, "a"), (2, "b")).toDF("id", "data").write.parquet(path)
@@ -145,8 +143,7 @@ class PathBasedTableSuite extends QueryTest with SharedSparkSession {
   test("catalog precedence: same-named catalog wins over SCO data source") {
     // Register a catalog under the same name as the SCO data source short name. SQL
     // resolution should route to the catalog; the SCO resolver is consulted only when
-    // no catalog claims the head, matching v1 file-format precedence (ResolveSQLOnFile)
-    // and Delta's ResolveDeltaPathTable extension.
+    // no catalog claims the head.
     withSQLConf("spark.sql.catalog.pathformat" -> classOf[InMemoryTableCatalog].getName) {
       sql(s"CREATE TABLE $tablePath (id INT, data STRING)")
       sql(s"INSERT INTO $tablePath VALUES (1, 'a')")

sql/core/src/test/scala/org/apache/spark/sql/connector/PathBasedTableTransactionSuite.scala

@@ -106,8 +106,7 @@ class PathBasedTableTransactionSuite extends RowLevelOperationSuiteBase {
     assert(txn.currentState === Committed)
     assert(txn.isClosed)
     // The transaction must have gone through the SCO seam to pathformat_cat, not the
-    // (also-transactional) session catalog. Without these checks the assertions above
-    // would silently pass when the session catalog absorbs the write.
+    // (also-transactional) session catalog.
     assert(pathformatCat.lastTransaction eq txn)
     assert(catalog.lastTransaction == null)
     checkAnswer(spark.table(tablePathWithFormat), Row(1, "a") :: Row(2, "b") :: Nil)