[eclipse#902] Do not split line endings in edits

Adds unit test to validate change.

fixes eclipse#902

org.eclipse.lsp4e.test/src/org/eclipse/lsp4e/test/edit/LSPEclipseUtilsTest.java

@@ -308,6 +308,26 @@ public void testTextEditInsertSameOffset() throws Exception {
 		LSPEclipseUtils.applyEdits(document, Arrays.asList(edits));
 		Assert.assertEquals(" throws Exception", document.get());
 	}
+
+	@Test
+	public void testTextEditSplittedLineEndings() throws Exception {
+		IProject project = null;
+		IEditorPart editor = null;
+		project = TestUtils.createProject(getClass().getSimpleName() + System.currentTimeMillis());
+		IFile file = TestUtils.createUniqueTestFile(project, "line1\r\nline2\r\nline3\r\n");
+		editor = TestUtils.openEditor(file);
+		ITextViewer viewer = LSPEclipseUtils.getTextViewer(editor);
+		// GIVEN a TextEdit which splits the '\r\n' line ending in the third line:
+		TextEdit[] edits = new TextEdit[] { new TextEdit(new Range(new Position(0, 0), new Position(2, 6)), "line3\r\nline2\r\nline1\r") };
+		IDocument document = viewer.getDocument();
+		int linesBeforeApplyEdits = document.getNumberOfLines();
+		// WHEN the TextEdit gets applied to the document:
+		LSPEclipseUtils.applyEdits(document, Arrays.asList(edits));
+		// THEN line1 has been swapped with line 3:
+		Assert.assertEquals("line3\r\nline2\r\nline1\r\n", document.get());
+		// AND the number of lines is still the same, because we have not appended a line:
+		Assert.assertEquals(linesBeforeApplyEdits, document.getNumberOfLines());
+	}
 
 	@Test
 	public void testURICreationUnix() {