Swift: Fix key path numbering in upgrade and downgrade scripts

Author: jketema

swift/downgrades/b7006eaacb007a06251596835506185619b86e98/key_path_components.ql

@@ -19,14 +19,19 @@ class ValueDeclOrNone extends @value_decl_or_none {
 }
 
 predicate isKeyPathComponentWithNewKind(KeyPathComponent id) {
-  key_path_components(id, 3, _) or key_path_components(id, 4, _)
+  key_path_components(id, 1, _) or key_path_components(id, 4, _)
 }
 
 query predicate new_key_path_components(KeyPathComponent id, int kind, TypeOrNone component_type) {
   exists(int old_kind |
     key_path_components(id, old_kind, component_type) and
     not isKeyPathComponentWithNewKind(id) and
-    if old_kind < 5 then kind = old_kind else kind = old_kind - 2
+    if old_kind = 0
+    then kind = old_kind
+    else
+      if old_kind = 2 or old_kind = 3
+      then kind = old_kind - 1
+      else kind = old_kind - 2
   )
 }
 

swift/ql/lib/upgrades/987ab0bc0911f8c88449210e21d2ee80ebcb488a/key_path_components.ql

@@ -9,5 +9,10 @@ class TypeOrNone extends @type_or_none {
 from KeyPathComponent id, int kind, int new_kind, TypeOrNone component_type
 where
   key_path_components(id, kind, component_type) and
-  if kind < 3 then new_kind = kind else new_kind = kind + 2
+  if kind = 0
+  then new_kind = kind
+  else
+    if kind = 1 or kind = 2
+    then new_kind = kind + 1
+    else new_kind = kind + 2
 select id, new_kind, component_type