Fix IndexError on strange backslash docstring (#506)

* Fix IndexError on strange backslash docstring

* Formatting fixes

Co-authored-by: Sambhav Kothari <[email protected]>

Author: asottile

docs/release_notes.rst

@@ -7,6 +7,10 @@ Release Notes
 Current Development Version
 ---------------------------
 
+Bug Fixes
+
+* Fix ``IndexError`` crash on one-line backslashed docstrings (#506).
+
 
 5.1.0 - August 22nd, 2020
 ---------------------------

src/pydocstyle/checker.py

@@ -284,10 +284,11 @@ def check_indent(self, definition, docstring):
                 indents = [leading_space(l) for l in lines if not is_blank(l)]
                 if set(' \t') == set(''.join(indents) + indent):
                     yield violations.D206()
-                if (len(indents) > 1 and min(indents[:-1]) > indent or
-                        indents[-1] > indent):
+                if (len(indents) > 1 and min(indents[:-1]) > indent) or (
+                    len(indents) > 0 and indents[-1] > indent
+                ):
                     yield violations.D208()
-                if min(indents) < indent:
+                if len(indents) > 0 and min(indents) < indent:
                     yield violations.D207()
 
     @check_for(Definition)

src/tests/test_cases/functions.py

@@ -70,3 +70,8 @@ class inner():
         pass
 
     pass
+
+
+def func_with_weird_backslash():
+    """Test a function with a weird backslash.\
+"""