Preserve empty CSV header positions

src/main/java/com/j256/simplecsv/processor/CsvProcessor.java

@@ -973,7 +973,8 @@ private String[] processHeader(String line, ParseError parseError, int lineNumbe
 							+ localParseError + "): " + lineInfo.line, lineInfo.linePos);
 				}
 			}
-			if (sb.length() > 0) {
+			if (!atEnd || (lineInfo.line.length() > 0
+					&& lineInfo.line.charAt(lineInfo.line.length() - 1) == columnSeparator)) {
 				headerColumns.add(sb.toString());
 			}
 			if (atEnd) {

src/test/java/com/j256/simplecsv/processor/EmptyHeaderTest.java

@@ -0,0 +1,54 @@
+package com.j256.simplecsv.processor;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+import java.io.BufferedReader;
+import java.io.StringReader;
+
+import org.junit.Test;
+import com.j256.simplecsv.common.CsvColumn;
+
+public class EmptyHeaderTest {
+    @Test
+    public void emptyHeaderPreservesColumnPositions() throws Exception {
+        CsvProcessor<Row> processor = new CsvProcessor<Row>(Row.class).withIgnoreUnknownColumns(true);
+        BufferedReader input = new BufferedReader(new StringReader("first,,second\nA,ignored,B\n"));
+        assertArrayEquals(new String[] {"first", "", "second"}, processor.readHeader(input, null));
+        Row row = processor.readRow(input, null);
+        assertEquals("A", row.first);
+        assertEquals("B", row.second);
+    }
+
+    @Test
+    public void quotedEmptyHeaderPreservesColumnPositions() throws Exception {
+        CsvProcessor<Row> processor = new CsvProcessor<Row>(Row.class).withIgnoreUnknownColumns(true);
+        BufferedReader input = new BufferedReader(new StringReader("first,\"\",second\nA,ignored,B\n"));
+        processor.readHeader(input, null);
+        assertEquals("B", processor.readRow(input, null).second);
+    }
+
+    @Test
+    public void leadingAndTrailingEmptyHeadersAreRetained() throws Exception {
+        CsvProcessor<Row> processor = new CsvProcessor<Row>(Row.class).withIgnoreUnknownColumns(true);
+        BufferedReader input = new BufferedReader(new StringReader(",first,second,\nignored,A,B,ignored\n"));
+        assertArrayEquals(new String[] {"", "first", "second", ""}, processor.readHeader(input, null));
+        Row row = processor.readRow(input, null);
+        assertEquals("A", row.first);
+        assertEquals("B", row.second);
+    }
+
+    @Test
+    public void ordinaryHeaderDoesNotGainAnExtraColumn() throws Exception {
+        CsvProcessor<Row> processor = new CsvProcessor<Row>(Row.class);
+        assertArrayEquals(new String[] {"first", "second"}, processor.readHeader(
+                new BufferedReader(new StringReader("first,second\n")), null));
+    }
+
+    public static class Row {
+        @CsvColumn
+        public String first;
+        @CsvColumn
+        public String second;
+    }
+}