Properly unpack dependencies into the staging area in build-single.

This requires build-single to take a dependency context tuple when
building chunks of a stratum. This context tuple is the surrounding
stratum which is used to construct the dependency graph in the worker
and then do a breadth-first search to collect all dependencies that need
to be added to the staging area.

Implementing this required a few hash/eq changes in Blob, Morphology
and Treeish as well as a few adjustments in the corresponding unit
tests.

1 files changed, 10 insertions, 2 deletions

diff --git a/morphlib/blobs.py b/morphlib/blobs.py
index 11f3e937..4c1190fb 100644
--- a/morphlib/blobs.py
+++ b/morphlib/blobs.py
@@ -35,10 +35,12 @@ class Blob(object):
         self.dependents = []
 
     def add_parent(self, parent):
-        self.parents.append(parent)
+        if not parent in self.parents:
+            self.parents.append(parent)
 
     def remove_parent(self, parent):
-        self.parents.remove(parent)
+        if parent in self.parents:
+            self.parents.remove(parent)
 
     def add_dependency(self, other):
         self.dependencies.append(other)
@@ -58,6 +60,12 @@ class Blob(object):
         else:
             return { self.morph.name: ['.'] }
 
+    def __eq__(self, other):
+        return self.morph == other.morph
+
+    def __hash__(self):
+        return hash(self.morph)
+
     def __str__(self): # pragma: no cover
         return str(self.morph)