Fixes ansible#5679: lineinfile ignores newline in line argument

library/files/lineinfile

@@ -348,7 +348,11 @@ def main():
         if ins_bef is None and ins_aft is None:
             ins_aft = 'EOF'
 
-        present(module, dest, params['regexp'], params['line'],
+        # Replace the newline character with an actual newline. Don't replace
+		# escaped \\n, hence sub and not str.replace.
+        line = re.sub(r'\n', os.linesep, params['line'])
+
+        present(module, dest, params['regexp'], line,
                 ins_aft, ins_bef, create, backup, backrefs)
     else:
         if params['regexp'] is None and params.get('line', None) is None:

test/TestRunner.py

@@ -512,6 +512,23 @@ def test_lineinfile(self):
         result = self._run(*testcase)
         assert result['failed']
 
+        # insert multiline at the end of the file
+        testline1 = '#12: The \\n character replaced with'
+        testline2 = 'an actual newline.'
+        testcase = ('lineinfile', [
+                    "dest=%s" % sample,
+                    "regexp='^#12: '",
+                    "line='%s\n%s'" % (testline1, testline2)
+                    ])
+        result = self._run(*testcase)
+        assert result['changed']
+        assert result['msg'] == 'line added'
+        artifact = [x.strip() for x in open(sample)]
+        assert artifact[-2] == testline1
+        assert artifact[-1] == testline2
+        assert artifact.count(testline1) == 1
+        assert artifact.count(testline2) == 1
+
         # cleanup
         os.unlink(sample)