Issue #582: disallow tabs before inline comments

Author: spaceone

pycodestyle.py

@@ -1092,9 +1092,11 @@ def whitespace_before_comment(logical_line, tokens):
     prev_end = (0, 0)
     for token_type, text, start, end, line in tokens:
         if token_type == tokenize.COMMENT:
-            inline_comment = line[:start[1]].strip()
+            inline_comment = line[:start[1]].strip(' ')
             if inline_comment:
-                if prev_end[0] == start[0] and start[1] < prev_end[1] + 2:
+                contains_tab = '\t' in line[prev_end[1]: prev_end[1] + 2]
+                nottwo = prev_end[0] == start[0] and start[1] < prev_end[1] + 2
+                if contains_tab or nottwo:
                     yield (prev_end,
                            "E261 at least two spaces before inline comment")
             symbol, sp, comment = text.partition(' ')

testsuite/E26.py

@@ -1,8 +1,16 @@
 #: E261:1:5
 pass # an inline comment
+#: E261:1:5
+pass 	# an inline comment
+#: E261:1:5
+pass	 # an inline comment
+#: E261:1:5
+pass		# an inline comment
 #: E262:1:12
 x = x + 1  #Increment x
 #: E262:1:12
+x = x + 1  #	Increment x
+#: E262:1:12
 x = x + 1  #  Increment x
 #: E262:1:12
 x = y + 1  #:  Increment x