Merge pull request #1183 from exponea/1138-fix-unintended-lstrip-behavior-change

Fix unintended lstrip_blocks behavior

Author: davidism

CHANGES.rst

@@ -25,6 +25,8 @@ Unreleased
  :pr:`1178`
 - The special ``namespace()`` assignment object in templates works in
  async environments. :issue:`1180`
+- Fix whitespace being removed before tags in the middle of lines when
+ ``lstrip_blocks`` is enabled. :issue:`1138`
 
 
 Version 2.11.1

src/jinja2/lexer.py

@@ -682,6 +682,7 @@ def tokeniter(self, source, name, filename=None, state=None):
  balancing_stack = []
  lstrip_unless_re = self.lstrip_unless_re
  newlines_stripped = 0
+ line_starting = True
 
  while 1:
  # tokenizer loop
@@ -731,11 +732,11 @@ def tokeniter(self, source, name, filename=None, state=None):
  ):
  # The start of text between the last newline and the tag.
  l_pos = text.rfind("\n") + 1
-
- # If there's only whitespace between the newline and the
- # tag, strip it.
- if not lstrip_unless_re.search(text, l_pos):
- groups = (text[:l_pos],) + groups[1:]
+ if l_pos > 0 or line_starting:
+  # If there's only whitespace between the newline and the
+  # tag, strip it.
+  if not lstrip_unless_re.search(text, l_pos):
+  groups = (text[:l_pos],) + groups[1:]
 
  for idx, token in enumerate(tokens):
  # failure group
@@ -794,6 +795,8 @@ def tokeniter(self, source, name, filename=None, state=None):
  yield lineno, tokens, data
  lineno += data.count("\n")
 
+ line_starting = m.group()[-1:] == "\n"
+
  # fetch new position into new variable so that we can check
  # if there is a internal parsing error which would result
  # in an infinite loop

tests/test_lexnparse.py

@@ -729,6 +729,98 @@ def test_lstrip_angle_bracket_compact(self, env):
  )
  assert tmpl.render(seq=range(5)) == "".join("%s\n" % x for x in range(5))
 
+ def test_lstrip_blocks_outside_with_new_line(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=False)
+ tmpl = env.from_string(
+ " {% if kvs %}(\n"
+ " {% for k, v in kvs %}{{ k }}={{ v }} {% endfor %}\n"
+ " ){% endif %}"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == "(\na=1 b=2 \n )"
+
+ def test_lstrip_trim_blocks_outside_with_new_line(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=True)
+ tmpl = env.from_string(
+ " {% if kvs %}(\n"
+ " {% for k, v in kvs %}{{ k }}={{ v }} {% endfor %}\n"
+ " ){% endif %}"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == "(\na=1 b=2 )"
+
+ def test_lstrip_blocks_inside_with_new_line(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=False)
+ tmpl = env.from_string(
+ " ({% if kvs %}\n"
+ " {% for k, v in kvs %}{{ k }}={{ v }} {% endfor %}\n"
+ " {% endif %})"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == " (\na=1 b=2 \n)"
+
+ def test_lstrip_trim_blocks_inside_with_new_line(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=True)
+ tmpl = env.from_string(
+ " ({% if kvs %}\n"
+ " {% for k, v in kvs %}{{ k }}={{ v }} {% endfor %}\n"
+ " {% endif %})"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == " (a=1 b=2 )"
+
+ def test_lstrip_blocks_without_new_line(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=False)
+ tmpl = env.from_string(
+ " {% if kvs %}"
+ " {% for k, v in kvs %}{{ k }}={{ v }} {% endfor %}"
+ " {% endif %}"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == " a=1 b=2 "
+
+ def test_lstrip_trim_blocks_without_new_line(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=True)
+ tmpl = env.from_string(
+ " {% if kvs %}"
+ " {% for k, v in kvs %}{{ k }}={{ v }} {% endfor %}"
+ " {% endif %}"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == " a=1 b=2 "
+
+ def test_lstrip_blocks_consume_after_without_new_line(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=False)
+ tmpl = env.from_string(
+ " {% if kvs -%}"
+ " {% for k, v in kvs %}{{ k }}={{ v }} {% endfor -%}"
+ " {% endif -%}"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == "a=1 b=2 "
+
+ def test_lstrip_trim_blocks_consume_before_without_new_line(self):
+ env = Environment(lstrip_blocks=False, trim_blocks=False)
+ tmpl = env.from_string(
+ " {%- if kvs %}"
+ " {%- for k, v in kvs %}{{ k }}={{ v }} {% endfor -%}"
+ " {%- endif %}"
+ )
+ out = tmpl.render(kvs=[("a", 1), ("b", 2)])
+ assert out == "a=1 b=2 "
+
+ def test_lstrip_trim_blocks_comment(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=True)
+ tmpl = env.from_string(" {# 1 space #}\n {# 2 spaces #} {# 4 spaces #}")
+ out = tmpl.render()
+ assert out == " " * 4
+
+ def test_lstrip_trim_blocks_raw(self):
+ env = Environment(lstrip_blocks=True, trim_blocks=True)
+ tmpl = env.from_string("{{x}}\n{%- raw %} {% endraw -%}\n{{ y }}")
+ out = tmpl.render(x=1, y=2)
+ assert out == "1 2"
+
  def test_php_syntax_with_manual(self, env):
  env = Environment(
  "<?", "?>", "<?=", "?>", "<!--", "-->", lstrip_blocks=True, trim_blocks=True