Report E131 instead of E121 / E126 for unaligned hanging indent

4 files changed, 26 insertions, 9 deletions

diff --git a/CHANGES.txt b/CHANGES.txt
index 82124be..963234d 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -25,6 +25,10 @@ Changes:
   for hanging indent" instead of indentation not being a
   multiple of 4.
 
+* Report E131 instead of E121 / E126 if the hanging indent is not
+  consistent within the same continuation block.  It helps when
+  error E121 or E126 is in the ``ignore`` list.
+
 * Report E126 instead of E121 when the continuation line is hanging
   with extra indentation, even if indentation is not a multiple of 4.
 
diff --git a/docs/intro.rst b/docs/intro.rst
index d88b792..0f1c077 100644
--- a/docs/intro.rst
+++ b/docs/intro.rst
@@ -212,6 +212,8 @@ This is the current list of error and warning codes:
 +----------+----------------------------------------------------------------------+
 | E129 (^) | visually indented line with same indent as next logical line         |
 +----------+----------------------------------------------------------------------+
+| E131 (^) | continuation line unaligned for hanging indent                       |
++----------+----------------------------------------------------------------------+
 | E133 (*) | closing bracket is missing indentation                               |
 +----------+----------------------------------------------------------------------+
 +----------+----------------------------------------------------------------------+
diff --git a/pep8.py b/pep8.py
index 91e3cca..e834f78 100755
--- a/pep8.py
+++ b/pep8.py
@@ -416,6 +416,7 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
     E127: a = (24,\n      42)
     E128: a = (24,\n    42)
     E129: if (a or\n    b):\n    pass
+    E131: a = (\n    42\n 24)
     """
     first_row = tokens[0][2][0]
     nrows = 1 + tokens[-1][2][0] - first_row
@@ -436,6 +437,8 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
     rel_indent = [0] * nrows
     # for each depth, collect a list of opening rows
     open_rows = [[0]]
+    # for each depth, memorize the hanging indentation
+    hangs = [None]
     # visual indents
     indent_chances = {}
     last_indent = tokens[0][2]
@@ -470,6 +473,8 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
                 hanging_indent = hang in valid_hangs
                 if hanging_indent:
                     break
+            if hangs[depth]:
+                hanging_indent = (hang == hangs[depth])
             # is there any chance of visual indent?
             visual_indent = (not close_bracket and hang > 0 and
                              indent_chances.get(start[1]))
@@ -493,10 +498,10 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
                 if close_bracket and not hang_closing:
                     yield (start, "E123 closing bracket does not match "
                            "indentation of opening bracket's line")
+                hangs[depth] = hang
             elif visual_indent is True:
                 # visual indent is verified
-                if not indent[depth]:
-                    indent[depth] = start[1]
+                indent[depth] = start[1]
             elif visual_indent in (text, str):
                 # ignore token lined up with matching one from a previous line
                 pass
@@ -506,10 +511,14 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
                     error = "E122", "missing indentation or outdented"
                 elif indent[depth]:
                     error = "E127", "over-indented for visual indent"
-                elif hang > 4:
-                    error = "E126", "over-indented for hanging indent"
+                elif not close_bracket and hangs[depth]:
+                    error = "E131", "unaligned for hanging indent"
                 else:
-                    error = "E121", "under-indented for hanging indent"
+                    hangs[depth] = hang
+                    if hang > 4:
+                        error = "E126", "over-indented for hanging indent"
+                    else:
+                        error = "E121", "under-indented for hanging indent"
                 yield start, "%s continuation line %s" % error
 
         # look for visual indenting
@@ -534,6 +543,7 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
             if text in '([{':
                 depth += 1
                 indent.append(0)
+                hangs.append(None)
                 if len(open_rows) == depth:
                     open_rows.append([])
                 open_rows[depth].append(row)
@@ -544,6 +554,7 @@ def continued_indentation(logical_line, tokens, indent_level, hang_closing,
             elif text in ')]}' and depth > 0:
                 # parent indents should not be more than this one
                 prev_indent = indent.pop() or last_indent[1]
+                hangs.pop()
                 for d in range(depth):
                     if indent[d] > prev_indent:
                         indent[d] = 0
diff --git a/testsuite/E12.py b/testsuite/E12.py
index ed12232..ac42886 100644
--- a/testsuite/E12.py
+++ b/testsuite/E12.py
@@ -58,11 +58,11 @@ rv.update(dict.fromkeys((
     'reasonComment_de', 'reasonComment_it'),
           '?'),
           "foo")
-#: E126 E126
+#: E126
 abricot = 3 + \
           4 + \
           5 + 6
-#: E126
+#: E131
 print "hello", (
 
     "there",
@@ -208,7 +208,7 @@ my_list = [
     1, 2, 3,
     4, 5, 6,
         ]
-#: E126 E126
+#: E126
 abris = 3 + \
         4 + \
         5 + 6
@@ -242,7 +242,7 @@ if (
     ) or
         y == 4):
     pass
-#: E126
+#: E131
 troublesome_hash = {
     "hash": "value",
     "long": "the quick brown fox jumps over the lazy dog before doing a "