Allow to get end-of-line characters for a RawText

Bug: 370320
Change-Id: I18adc63596f4657516ccc6d704a561924c79d445
Signed-off-by: Kevin Sawicki <kevin@github.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/RawTextTest.java

@@ -46,6 +46,7 @@ package org.eclipse.jgit.diff;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import java.io.ByteArrayOutputStream;
@@ -189,6 +190,46 @@ public class RawTextTest {
 		assertEquals(new Edit(0, 1, 0, 2), e);
 	}
 
+	@Test
+	public void testLineDelimiter() throws Exception {
+		RawText rt = new RawText(Constants.encodeASCII("foo\n"));
+		assertEquals("\n", rt.getLineDelimiter());
+		assertFalse(rt.isMissingNewlineAtEnd());
+		rt = new RawText(Constants.encodeASCII("foo\r\n"));
+		assertEquals("\r\n", rt.getLineDelimiter());
+		assertFalse(rt.isMissingNewlineAtEnd());
+
+		rt = new RawText(Constants.encodeASCII("foo\nbar"));
+		assertEquals("\n", rt.getLineDelimiter());
+		assertTrue(rt.isMissingNewlineAtEnd());
+		rt = new RawText(Constants.encodeASCII("foo\r\nbar"));
+		assertEquals("\r\n", rt.getLineDelimiter());
+		assertTrue(rt.isMissingNewlineAtEnd());
+
+		rt = new RawText(Constants.encodeASCII("foo\nbar\r\n"));
+		assertEquals("\n", rt.getLineDelimiter());
+		assertFalse(rt.isMissingNewlineAtEnd());
+		rt = new RawText(Constants.encodeASCII("foo\r\nbar\n"));
+		assertEquals("\r\n", rt.getLineDelimiter());
+		assertFalse(rt.isMissingNewlineAtEnd());
+
+		rt = new RawText(Constants.encodeASCII("foo"));
+		assertNull(rt.getLineDelimiter());
+		assertTrue(rt.isMissingNewlineAtEnd());
+
+		rt = new RawText(Constants.encodeASCII(""));
+		assertNull(rt.getLineDelimiter());
+		assertTrue(rt.isMissingNewlineAtEnd());
+
+		rt = new RawText(Constants.encodeASCII("\n"));
+		assertEquals("\n", rt.getLineDelimiter());
+		assertFalse(rt.isMissingNewlineAtEnd());
+
+		rt = new RawText(Constants.encodeASCII("\r\n"));
+		assertEquals("\r\n", rt.getLineDelimiter());
+		assertFalse(rt.isMissingNewlineAtEnd());
+	}
+
 	private static RawText t(String text) {
 		StringBuilder r = new StringBuilder();
 		for (int i = 0; i < text.length(); i++) {

org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java

@@ -276,4 +276,21 @@ public class RawText extends Sequence {
 
 		return false;
 	}
+
+	/**
+	 * Get the line delimiter for the first line.
+	 *
+	 * @return the line delimiter or <code>null</code>
+	 */
+	public String getLineDelimiter() {
+		if (size() == 0)
+			return null;
+		int e = getEnd(0);
+		if (content[e - 1] != '\n')
+			return null;
+		if (content.length > 1 && content[e - 2] == '\r')
+			return "\r\n";
+		else
+			return "\n";
+	}
 }