Deprecate and ignore newlinestr

Lib/fontTools/misc/xmlWriter.py

@@ -4,6 +4,7 @@ from fontTools.misc.py23 import byteord, strjoin, tobytes, tostr
 import sys
 import os
 import string
+import warnings
 
 INDENT = "  "
 
@@ -37,10 +38,12 @@ class XMLWriter(object):
 			self.file.write('')
 			self.totype = tostr
 		self.indentwhite = self.totype(indentwhite)
-		if newlinestr is None:
+		if newlinestr != "\n":
-			self.newlinestr = self.totype(os.linesep)
+			warnings.warn(
-		else:
+				'Setting "newlinestr" is deprecated and will be ignored.',
-			self.newlinestr = self.totype(newlinestr)
+				DeprecationWarning,
+			)
+		self.newlinestr = self.totype("\n")
 		self.indentlevel = 0
 		self.stack = []
 		self.needindent = 1

Lib/fontTools/ttLib/tables/_g_l_y_f.py

@@ -159,8 +159,7 @@ class table__g_l_y_f(DefaultTable.DefaultTable):
 						suffix=ext)
 					existingGlyphFiles.add(glyphPath.lower())
 					glyphWriter = xmlWriter.XMLWriter(
-						glyphPath, idlefunc=writer.idlefunc,
+						glyphPath, idlefunc=writer.idlefunc)
-						newlinestr=writer.newlinestr)
 					glyphWriter.begintag("ttFont", ttLibVersion=version)
 					glyphWriter.newline()
 					glyphWriter.begintag("glyf")

Lib/fontTools/ttLib/ttFont.py

@@ -271,8 +271,7 @@ class TTFont(object):
 			tag = tables[i]
 			if splitTables:
 				tablePath = fileNameTemplate % tagToIdentifier(tag)
-				tableWriter = xmlWriter.XMLWriter(tablePath,
+				tableWriter = xmlWriter.XMLWriter(tablePath)
-						newlinestr=writer.newlinestr)
 				tableWriter.begintag("ttFont", ttLibVersion=version)
 				tableWriter.newline()
 				tableWriter.newline()

Tests/misc/xmlWriter_test.py

@@ -115,7 +115,7 @@ class TestXMLWriter(unittest.TestCase):
 			writer.write("world")
 			writer.newline()
 
-			linesep = tobytes(os.linesep) if nls is None else tobytes(nls)
+			linesep = tobytes('\n')
 
 			self.assertEqual(
 				header + linesep + b"hello" + linesep + b"world" + linesep,

Tests/ttLib/tables/_n_a_m_e_test.py

@@ -354,7 +354,7 @@ class NameRecordTest(unittest.TestCase):
 		writer = XMLWriter(BytesIO())
 		name.toXML(writer, ttFont=None)
 		xml = writer.file.getvalue().decode("utf_8").strip()
-		return xml.split(writer.newlinestr.decode("utf_8"))[1:]
+		return xml.split("\n")[1:]
 
 	def test_toXML_utf16be(self):
 		name = makeName("Foo Bold", 111, 0, 2, 7)