expand comment marker test to contrast printed comment with quoted value

Author: rootvector2

src/test/java/org/apache/commons/csv/CSVPrinterTest.java

@@ -1835,15 +1835,24 @@ void testQuoteCommentMarkerFirstChar() throws IOException {
         final StringWriter sw = new StringWriter();
         final String col1 = ";comment-like";
         try (CSVPrinter printer = new CSVPrinter(sw, format)) {
+            // A real comment is written with the marker, unquoted.
+            printer.printComment("a real comment");
+            // A value starting with the marker is quoted, so it does not read back as a comment.
             printer.printRecord(col1, "b");
+            // The marker past the first character does not start a comment, so only the leading-marker value is quoted.
+            printer.printRecord("a;b", ";c");
         }
-        assertEquals("\";comment-like\",b" + RECORD_SEPARATOR, sw.toString());
-        // A value starting with the comment marker must read back as data, not a dropped comment line.
+        assertEquals("; a real comment" + RECORD_SEPARATOR +
+                "\";comment-like\",b" + RECORD_SEPARATOR +
+                "a;b,\";c\"" + RECORD_SEPARATOR, sw.toString());
+        // The comment is dropped on read; both data records survive intact.
         try (CSVParser parser = CSVParser.parse(sw.toString(), format)) {
             final List<CSVRecord> records = parser.getRecords();
-            assertEquals(1, records.size());
+            assertEquals(2, records.size());
             assertEquals(col1, records.get(0).get(0));
             assertEquals("b", records.get(0).get(1));
+            assertEquals("a;b", records.get(1).get(0));
+            assertEquals(";c", records.get(1).get(1));
         }
     }