Fix line offset for 'invalid escape sequence'

Author: asottile

CONTRIBUTING.rst

@@ -62,7 +62,7 @@ All the tests should pass for all available interpreters, with the summary of::
 
     congratulations :)
 
-At this point you can create a pull request back to the official pycodestyles
+At this point you can create a pull request back to the official pycodestyle
 repository for review! For more information on how to make a pull request,
 GitHub has an excellent `guide`_.
 

pycodestyle.py

@@ -1522,6 +1522,7 @@ def python_3000_invalid_escape_sequence(logical_line, tokens):
 
     for token_type, text, start, end, line in tokens:
         if token_type == tokenize.STRING:
+            orig_start = start
             quote = text[-3:] if text[-3:] in ('"""', "'''") else text[-1]
             # Extract string modifiers (e.g. u or r)
             quote_pos = text.index(quote)
@@ -1535,7 +1536,7 @@ def python_3000_invalid_escape_sequence(logical_line, tokens):
                     pos += 1
                     if string[pos] not in valid:
                         yield (
-                            line.lstrip().find(text),
+                            orig_start,
                             "W605 invalid escape sequence '\\%s'" %
                             string[pos],
                         )

testsuite/W60.py

@@ -19,6 +19,10 @@
 regex = '''
 \.png$
 '''
+#: W605:2:5
+f(
+    '\_'
+)
 #: Okay
 regex = r'\.png$'
 regex = '\\.png$'