Stabilize formatting of invalid WHERE clauses.

CHANGELOG

@@ -24,6 +24,7 @@ Bug Fixes
 * Fix splitting when using DECLARE ... HANDLER (issue581).
 * Fix splitting of statements using CASE ... WHEN (issue580).
 * Improve formatting of type casts in parentheses.
+* Stabilize formatting of invalid SQL statements.
 
 
 Release 0.3.1 (Feb 29, 2020)

sqlparse/filters/reindent.py

@@ -102,7 +102,10 @@ class ReindentFilter:
 
     def _process_where(self, tlist):
         tidx, token = tlist.token_next_by(m=(T.Keyword, 'WHERE'))
+        if not token:
+            return
         # issue121, errors in statement fixed??
+        print(tidx, token, tlist)
         tlist.insert_before(tidx, self.nl())
 
         with indent(self):

tests/test_regressions.py

@@ -405,3 +405,9 @@ def test_as_in_parentheses_indents():
     # did raise NoneType has no attribute is_group in _process_parentheses
     formatted = sqlparse.format('(as foo)', reindent=True)
     assert formatted == '(as foo)'
+
+
+def test_format_invalid_where_clause():
+    # did raise ValueError
+    formatted = sqlparse.format('where, foo', reindent=True)
+    assert formatted == 'where, foo'