morph edit: Recursively edit strata

Previously the code would edit strata that dependended on the stratum
being edited, but would ignore the dependency chain beyond that. In
fact, we need to edit all strata in the dependency chain to avoid
having two different versions of a stratum in the same build.

This splits the modification into two steps: changing the stratum that
points to the chunk, and recursively changing references to any strata
that have been altered.

1 files changed, 66 insertions, 33 deletions

diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py
index 14dc9782..71082445 100644
--- a/morphlib/plugins/branch_and_merge_plugin.py
+++ b/morphlib/plugins/branch_and_merge_plugin.py
@@ -671,51 +671,84 @@ class BranchAndMergePlugin(cliapp.Plugin):
         # Test that the specified stratum exists in the system
         self.get_edit_info(system_name, system_morphology, stratum_name)
 
-        for stratum_spec in system_morphology['strata']:
+        all_strata = system_morphology['strata']
+        stratum_refs_to_correct = set()
+
+        # Petrify the chunk
+        for stratum_spec in (s for s in all_strata
+                             if s['morph'] == stratum_name):
             stratum_repo_dir = self.make_available(
                 stratum_spec, branch, branch_dir, root_repo, root_repo_dir)
             stratum_morphology = self.load_morphology(
                 stratum_repo_dir, stratum_spec['morph'])
-            changed = False
 
-            if stratum_spec['morph'] == stratum_name:
-                if chunk_name is not None:
-                    # Change the stratum's ref to the chunk
-                    chunk_spec = self.get_edit_info(
-                        stratum_name, stratum_morphology, chunk_name,
-                        collection='chunks')
+            if chunk_name is not None:
+                # Change the stratum's ref to the chunk
+                chunk_spec = self.get_edit_info(
+                    stratum_name, stratum_morphology, chunk_name,
+                    collection='chunks')
 
-                    if 'unpetrify-ref' in chunk_spec:
-                        chunk_spec['ref'] = chunk_spec['unpetrify-ref']
-                        del chunk_spec['unpetrify-ref']
+                if 'unpetrify-ref' in chunk_spec:
+                    chunk_spec['ref'] = chunk_spec['unpetrify-ref']
+                    del chunk_spec['unpetrify-ref']
 
-                    self.make_available(
-                        chunk_spec, branch, branch_dir, root_repo,
-                        root_repo_dir)
+                self.make_available(
+                    chunk_spec, branch, branch_dir, root_repo,
+                    root_repo_dir)
 
-                    if chunk_spec['ref'] != branch:
-                        chunk_spec['ref'] = branch
+                if chunk_spec['ref'] != branch:
+                    chunk_spec['ref'] = branch
 
-                    self.log_change(stratum_spec['repo'],
-                        '"%s" now includes "%s" from "%s"' %
-                        (stratum_name, chunk_name, branch))
-                changed = True
-            else:
-                # Update build-depends in other strata that point to this one
-                if stratum_morphology['build-depends'] is not None:
+                self.log_change(stratum_spec['repo'],
+                    '"%s" now includes "%s" from "%s"' %
+                    (stratum_name, chunk_name, branch))
+            stratum_refs_to_correct.add((stratum_spec['repo'],
+                                         stratum_spec['ref'],
+                                         stratum_spec['morph']))
+            # Correct the System Morphology's reference
+            stratum_spec['ref'] = branch
+            self.save_morphology(stratum_repo_dir, stratum_spec['morph'],
+                                 stratum_morphology)
+            self.log_change(root_repo,
+                '"%s" now includes "%s" from "%s"' %
+                (system_name, stratum_name, branch))
+
+        # Correct all references to altered strata
+        while stratum_refs_to_correct:
+            repo, ref, morph = stratum_refs_to_correct.pop()
+            spec = {"repo": repo, "ref": ref, "morph": morph}
+            for stratum_spec in all_strata:
+                changed = False
+                if repo == root_repo:
+                    stratum_repo_dir = root_repo_dir
+                else:
+                    stratum_repo_dir = self.checkout_repository(
+                        branch_dir, stratum_spec['repo'],
+                        branch, stratum_spec['ref'])
+                stratum_morphology = self.load_morphology(
+                    stratum_repo_dir, stratum_spec['morph'])
+                if ('build-depends' in stratum_morphology
+                    and stratum_morphology['build-depends'] is not None):
                     for bd_spec in stratum_morphology['build-depends']:
-                        if bd_spec['morph'] == stratum_name:
+                        bd_triplet = (bd_spec['repo'],
+                                      bd_spec['ref'],
+                                      bd_spec['morph'])
+                        if (bd_triplet == (repo, ref, morph)):
                             bd_spec['ref'] = branch
                             changed = True
-                            break
-
-            if changed:
-                stratum_spec['ref'] = branch
-                self.save_morphology(stratum_repo_dir, stratum_spec['morph'],
-                                     stratum_morphology)
-                self.log_change(root_repo,
-                    '"%s" now includes "%s" from "%s"' %
-                    (system_name, stratum_name, branch))
+                    if changed:
+                        stratum_refs_to_correct.add((stratum_spec['repo'],
+                                                     stratum_spec['ref'],
+                                                     stratum_spec['morph']))
+                        # Update the System morphology to use
+                        # the modified version of the Stratum
+                        stratum_spec['ref'] = branch
+                        self.save_morphology(stratum_repo_dir,
+                                             stratum_spec['morph'],
+                                             stratum_morphology)
+                        self.log_change(root_repo,
+                            '"%s" now includes "%s" from "%s"' %
+                            (system_name, stratum_name, branch))
 
         self.save_morphology(root_repo_dir, system_name, system_morphology)