Fix for ScriptUtils failure when '--' occurs inside a multi-line comment on the same line as '*/' (#22392)

* Test for multi-line comment block where the comment end delimiter occurs on a line starting with the single-line comment prefix
* ScriptUtils successfully parses a SQL script containing a multi-line comment block where the comment-end delimiter occurs on a line starting with the single-line comment prefix.

spring-jdbc/src/test/java/org/springframework/jdbc/datasource/init/ScriptUtilsUnitTests.java

@@ -162,6 +162,20 @@ public class ScriptUtilsUnitTests {
 		assertEquals("statement 2 not split correctly", statement2, statements.get(1));
 	}
 
+	@Test
+	public void readAndSplitScriptContainingMultiLineNestedComments() throws Exception {
+		String script = readScript("test-data-with-multi-line-nested-comments.sql");
+		List<String> statements = new ArrayList<>();
+		splitSqlScript(script, ';', statements);
+
+		String statement1 = "INSERT INTO users(first_name, last_name) VALUES('Juergen', 'Hoeller')";
+		String statement2 = "INSERT INTO users(first_name, last_name) VALUES( 'Sam' , 'Brannen' )";
+
+		assertEquals("wrong number of statements", 2, statements.size());
+		assertEquals("statement 1 not split correctly", statement1, statements.get(0));
+		assertEquals("statement 2 not split correctly", statement2, statements.get(1));
+	}
+
 	@Test
 	public void containsDelimiters() {
 		assertFalse(containsSqlScriptDelimiters("select 1\n select ';'", ";"));

spring-jdbc/src/test/resources/org/springframework/jdbc/datasource/init/test-data-with-multi-line-nested-comments.sql

@@ -0,0 +1,23 @@
+/* This is a multi line comment
+ * The next comment line has no text
+
+ * The next comment line starts with a space.
+ *  x, y, z...
+ */
+
+INSERT INTO users(first_name, last_name) VALUES('Juergen', 'Hoeller');
+-- This is also a comment.
+/*-------------------------------------------
+-- A fancy multi-line comments that puts
+-- single line comments inside of a multi-line
+-- comment block.
+Moreover, the block commend end delimiter
+appears on a line that can potentially also
+be a single-line comment if we weren't
+already inside a multi-line comment run.
+-------------------------------------------*/
+ INSERT INTO
+users(first_name, last_name)    -- This is a single line comment containing the block-end-comment sequence here */ but it's still a single-line comment
+VALUES( 'Sam'     -- first_name
+      , 'Brannen' -- last_name
+);--