Merge remote-tracking branch 'wking/keep-trailing-newline'

5 files changed, 42 insertions, 6 deletions

diff --git a/jinja2/defaults.py b/jinja2/defaults.py
index 3201271..8216450 100644
--- a/jinja2/defaults.py
+++ b/jinja2/defaults.py
@@ -23,6 +23,7 @@ LINE_STATEMENT_PREFIX = None
 LINE_COMMENT_PREFIX = None
 TRIM_BLOCKS = False
 NEWLINE_SEQUENCE = '\n'
+KEEP_TRAILING_NEWLINE = False
 
 
 # default filters, tests and namespace
diff --git a/jinja2/environment.py b/jinja2/environment.py
index 58573a2..23d00aa 100644
--- a/jinja2/environment.py
+++ b/jinja2/environment.py
@@ -15,7 +15,8 @@ from jinja2.defaults import BLOCK_START_STRING, \
      BLOCK_END_STRING, VARIABLE_START_STRING, VARIABLE_END_STRING, \
      COMMENT_START_STRING, COMMENT_END_STRING, LINE_STATEMENT_PREFIX, \
      LINE_COMMENT_PREFIX, TRIM_BLOCKS, NEWLINE_SEQUENCE, \
-     DEFAULT_FILTERS, DEFAULT_TESTS, DEFAULT_NAMESPACE
+     DEFAULT_FILTERS, DEFAULT_TESTS, DEFAULT_NAMESPACE, \
+     KEEP_TRAILING_NEWLINE
 from jinja2.lexer import get_lexer, TokenStream
 from jinja2.parser import Parser
 from jinja2.optimizer import optimize
@@ -147,6 +148,13 @@ class Environment(object):
             useful default for Linux and OS X systems as well as web
             applications.
 
+        `keep_trailing_newline`
+            Preserve the trailing newline when rendering templates.
+            The default is ``False``, which causes a single newline,
+            if present, to be stripped from the end of the template.
+
+            .. versionadded:: 2.7
+
         `extensions`
             List of Jinja extensions to use.  This can either be import paths
             as strings or extension classes.  For more information have a
@@ -232,6 +240,7 @@ class Environment(object):
                  line_comment_prefix=LINE_COMMENT_PREFIX,
                  trim_blocks=TRIM_BLOCKS,
                  newline_sequence=NEWLINE_SEQUENCE,
+                 keep_trailing_newline=KEEP_TRAILING_NEWLINE,
                  extensions=(),
                  optimized=True,
                  undefined=Undefined,
@@ -263,6 +272,7 @@ class Environment(object):
         self.line_comment_prefix = line_comment_prefix
         self.trim_blocks = trim_blocks
         self.newline_sequence = newline_sequence
+        self.keep_trailing_newline = keep_trailing_newline
 
         # runtime information
         self.undefined = undefined
@@ -828,6 +838,7 @@ class Template(object):
                 line_comment_prefix=LINE_COMMENT_PREFIX,
                 trim_blocks=TRIM_BLOCKS,
                 newline_sequence=NEWLINE_SEQUENCE,
+                keep_trailing_newline=KEEP_TRAILING_NEWLINE,
                 extensions=(),
                 optimized=True,
                 undefined=Undefined,
@@ -837,8 +848,8 @@ class Template(object):
             block_start_string, block_end_string, variable_start_string,
             variable_end_string, comment_start_string, comment_end_string,
             line_statement_prefix, line_comment_prefix, trim_blocks,
-            newline_sequence, frozenset(extensions), optimized, undefined,
-            finalize, autoescape, None, 0, False, None)
+            newline_sequence, keep_trailing_newline, frozenset(extensions),
+            optimized, undefined, finalize, autoescape, None, 0, False, None)
         return env.from_string(source, template_class=cls)
 
     @classmethod
diff --git a/jinja2/ext.py b/jinja2/ext.py
index 495e643..651ee98 100644
--- a/jinja2/ext.py
+++ b/jinja2/ext.py
@@ -589,7 +589,9 @@ def babel_extract(fileobj, keywords, comment_tags, options):
         options.get('line_statement_prefix') or LINE_STATEMENT_PREFIX,
         options.get('line_comment_prefix') or LINE_COMMENT_PREFIX,
         getbool(options, 'trim_blocks', TRIM_BLOCKS),
-        NEWLINE_SEQUENCE, frozenset(extensions),
+        NEWLINE_SEQUENCE,
+        getbool(options, 'keep_trailing_newline', KEEP_TRAILING_NEWLINE),
+        frozenset(extensions),
         cache_size=0,
         auto_reload=False
     )
diff --git a/jinja2/lexer.py b/jinja2/lexer.py
index bd2e861..5594e0a 100644
--- a/jinja2/lexer.py
+++ b/jinja2/lexer.py
@@ -391,7 +391,8 @@ def get_lexer(environment):
            environment.line_statement_prefix,
            environment.line_comment_prefix,
            environment.trim_blocks,
-           environment.newline_sequence)
+           environment.newline_sequence,
+           environment.keep_trailing_newline)
     lexer = _lexer_cache.get(key)
     if lexer is None:
         lexer = Lexer(environment)
@@ -434,6 +435,7 @@ class Lexer(object):
         block_suffix_re = environment.trim_blocks and '\\n?' or ''
 
         self.newline_sequence = environment.newline_sequence
+        self.keep_trailing_newline = environment.keep_trailing_newline
 
         # global lexing rules
         self.rules = {
@@ -557,7 +559,14 @@ class Lexer(object):
         """This method tokenizes the text and returns the tokens in a
         generator.  Use this method if you just want to tokenize a template.
         """
-        source = '\n'.join(six.text_type(source).splitlines())
+        source = six.text_type(source)
+        lines = source.splitlines()
+        if self.keep_trailing_newline and source:
+            for newline in ('\r\n', '\r', '\n'):
+                if source.endswith(newline):
+                    lines.append('')
+                    break
+        source = '\n'.join(lines)
         pos = 0
         lineno = 1
         stack = ['root']
diff --git a/jinja2/testsuite/lexnparse.py b/jinja2/testsuite/lexnparse.py
index f05f601..7022e23 100644
--- a/jinja2/testsuite/lexnparse.py
+++ b/jinja2/testsuite/lexnparse.py
@@ -108,6 +108,19 @@ class LexerTestCase(JinjaTestCase):
             result = tmpl.render()
             assert result.replace(seq, 'X') == '1X2X3X4'
 
+    def test_trailing_newline(self):
+        for keep in [True, False]:
+            env = Environment(keep_trailing_newline=keep)
+            for template,expected in [
+                    ('', {}),
+                    ('no\nnewline', {}),
+                    ('with\nnewline\n', {False: 'with\nnewline'}),
+                    ('with\nseveral\n\n\n', {False: 'with\nseveral\n\n'}),
+                    ]:
+                tmpl = env.from_string(template)
+                expect = expected.get(keep, template)
+                result = tmpl.render()
+                assert result == expect, (keep, template, result, expect)
 
 class ParserTestCase(JinjaTestCase):