Check bottom and invariants

This code adds some checks that the bottom is actually always the
parent of top.

It also checks that the top is the same as what the patch ref points
to.

This is only to ensure that the next patches are correct.

Signed-off-by: David Kågedal <davidk@lysator.liu.se>
Signed-off-by: Karl Hasselström <kha@treskal.com>

diff --git a/stgit/stack.py b/stgit/stack.py
index f1f75e49802ef0181597349e2aadb20d9cf03f8a..f54bec4453f1bd7e2cc1f503f64499f2973019e8 100644 (file)
--- a/stgit/stack.py
+++ b/stgit/stack.py
@@ -208,9 +208,15 @@ class Patch(StgitObject):
             self.__update_top_ref(top)
 
     def get_old_bottom(self):
-        return self._get_field('bottom.old')
+        old_bottom = self._get_field('bottom.old')
+        old_top = self.get_old_top()
+        assert old_bottom == git.get_commit(old_top).get_parent()
+        return old_bottom
 
     def get_bottom(self):
+        bottom = self._get_field('bottom')
+        top = self.get_top()
+        assert bottom == git.get_commit(top).get_parent()
         return self._get_field('bottom')
 
     def set_bottom(self, value, backup = False):
@@ -223,7 +229,13 @@ class Patch(StgitObject):
         return self._get_field('top.old')
 
     def get_top(self):
-        return self._get_field('top')
+        top = self._get_field('top')
+        try:
+            ref = git.rev_parse(self.__top_ref)
+        except:
+            ref = None
+        assert not ref or top == ref
+        return top
 
     def set_top(self, value, backup = False):
         if backup:
@@ -231,6 +243,7 @@ class Patch(StgitObject):
             self._set_field('top.old', curr)
         self._set_field('top', value)
         self.__update_top_ref(value)
+        self.get_bottom() # check the assert
 
     def restore_old_boundaries(self):
         bottom = self._get_field('bottom.old')