Reposition before recursion in fixes to avoid internal error

plugins/sqlfluff-templater-dbt/test/templater_test.py

@@ -295,15 +295,21 @@ def test__dbt_templated_models_do_not_raise_lint_error(
     assert len(violations) == 0
 
 
+def _clean_path(glob_expression):
+    """Clear out files matching the provided glob expression."""
+    for fsp in glob.glob(glob_expression):
+        os.remove(fsp)
+
+
 @pytest.mark.parametrize(
     "path", ["models/my_new_project/issue_1608.sql", "snapshots/issue_1771.sql"]
 )
 def test__dbt_templated_models_fix_does_not_corrupt_file(
     project_dir, path  # noqa: F811
 ):
-    """Test fix for issue 1608. Previously "sqlfluff fix" corrupted the file."""
-    for fsp in glob.glob(os.path.join(project_dir, "snapshots", "*FIXED.sql")):
-        os.remove(fsp)
+    """Test issues where previously "sqlfluff fix" corrupted the file."""
+    test_glob = os.path.join(project_dir, os.path.dirname(path), "*FIXED.sql")
+    _clean_path(test_glob)
     lntr = Linter(config=FluffConfig(configs=DBT_FLUFF_CONFIG))
     lnt = lntr.lint_path(os.path.join(project_dir, path), fix=True)
     try:
@@ -314,8 +320,7 @@ def test__dbt_templated_models_fix_does_not_corrupt_file(
             fixed_buff = f.read()
         assert fixed_buff == comp_buff
     finally:
-        for fsp in glob.glob(os.path.join(project_dir, "snapshots", "*FIXED.sql")):
-            os.remove(fsp)
+        _clean_path(test_glob)
 
 
 def test__templater_dbt_templating_absolute_path(

src/sqlfluff/core/parser/segments/base.py

@@ -1275,6 +1275,16 @@ def apply_fixes(
                 # Invalidate any caches
                 self.invalidate_caches()
 
+            # If any fixes applied, do an intermediate reposition. When applying
+            # fixes to children and then trying to reposition them, that recursion
+            # may rely on the parent having already populated positions for any
+            # of the fixes applied there first. This ensures those segments have
+            # working positions to work with.
+            if fixes_applied:
+                seg_buffer = list(
+                    self._position_segments(tuple(seg_buffer), parent_pos=r.pos_marker)
+                )
+
             # Then recurse (i.e. deal with the children) (Requeueing)
             seg_queue = seg_buffer
             seg_buffer = []

test/fixtures/rules/std_rule_cases/L032.yml

@@ -47,3 +47,12 @@ select_using_fail:
         SELECT margin
         FROM B_TABLE
     ) USING (SOME_COLUMN)
+
+test_fail_parent_child_positioning:
+  # Check for issue from https://github.com/sqlfluff/sqlfluff/issues/3656
+  fail_str: |
+    select * from c1 join c2 using (ID)
+    join (select * from c3 join c4 using (ID)) as c5 on c1.ID = c5.ID
+  fix_str: |
+    select * from c1 join c2 ON c1.ID = c2.ID
+    join (select * from c3 join c4 ON c3.ID = c4.ID) as c5 on c1.ID = c5.ID