b&m: re-implement morph unpetrify

This also undoes the test suite change to keep it using the old petrify.

Petrify and Unpetrify have the same structure:

1. Set up
2. Load all the morphologies
3. Make changes to the morphologies
4. Write back any changes

This suggests some re-use in the form of passing a function callback to
a morphology visitor.

3 files changed, 49 insertions, 3 deletions

diff --git a/morphlib/plugins/branch_and_merge_new_plugin.py b/morphlib/plugins/branch_and_merge_new_plugin.py
index 971c1328..aafc8dcd 100644
--- a/morphlib/plugins/branch_and_merge_new_plugin.py
+++ b/morphlib/plugins/branch_and_merge_new_plugin.py
@@ -46,6 +46,8 @@ class SimpleBranchAndMergePlugin(cliapp.Plugin):
         self.app.add_subcommand(
             'petrify', self.petrify, arg_synopsis='')
         self.app.add_subcommand(
+            'unpetrify', self.unpetrify, arg_synopsis='')
+        self.app.add_subcommand(
             'show-system-branch', self.show_system_branch, arg_synopsis='')
         self.app.add_subcommand(
             'show-branch-root', self.show_branch_root, arg_synopsis='')
@@ -608,7 +610,7 @@ class SimpleBranchAndMergePlugin(cliapp.Plugin):
             self.app.output.flush()
 
     def _load_all_sysbranch_morphologies(self, sb, loader):
-        # Read in all the morphologies in the root repository.
+        '''Read in all the morphologies in the root repository.'''
         self.app.status(msg='Loading in all morphologies')
         morphs = morphlib.morphset.MorphologySet()
         mf = morphlib.morphologyfinder.MorphologyFinder(
@@ -695,3 +697,47 @@ class SimpleBranchAndMergePlugin(cliapp.Plugin):
 
         # Write morphologies back out again.
         self._save_dirty_morphologies(loader, sb, morphs.morphologies)
+
+    def unpetrify(self, args):
+        '''Reverse the process of petrification.
+
+        This undoes the changes `morph petrify` did.
+
+        '''
+
+        if args:
+            raise cliapp.AppException('morph petrify takes no arguments')
+
+        ws = morphlib.workspace.open('.')
+        sb = morphlib.sysbranchdir.open_from_within('.')
+        loader = morphlib.morphloader.MorphologyLoader()
+        lrc, rrc = morphlib.util.new_repo_caches(self.app)
+        update_repos = not self.app.settings['no-git-update']
+        done = set()
+
+        morphs = self._load_all_sysbranch_morphologies(sb, loader)
+
+        # Restore the ref for each stratum and chunk
+        def unpetrify_specs(specs):
+            dirty = False
+            for spec in specs:
+                ref = spec['ref']
+                # Don't attempt to unpetrify refs which aren't petrified
+                if not ('unpetrify-ref' in spec
+                        and morphlib.git.is_valid_sha1(ref)):
+                    continue
+                spec['ref'] = spec.pop('unpetrify-ref')
+                dirty = True
+            return dirty
+
+        for m in morphs.morphologies:
+            dirty = False
+            if m['kind'] == 'system':
+                dirty = dirty or unpetrify_specs(m['strata'])
+            elif m['kind'] == 'stratum':
+                dirty = dirty or unpetrify_specs(m['build-depends'])
+                dirty = dirty or unpetrify_specs(m['chunks'])
+            m.dirty = True
+
+        # Write morphologies back out again.
+        self._save_dirty_morphologies(loader, sb, morphs.morphologies)
diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py
index 4791989b..671071b6 100644
--- a/morphlib/plugins/branch_and_merge_plugin.py
+++ b/morphlib/plugins/branch_and_merge_plugin.py
@@ -62,7 +62,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
 #        self.app.add_subcommand('edit', self.edit,
 #                                arg_synopsis='SYSTEM STRATUM [CHUNK]')
         self.app.add_subcommand('old-petrify', self.petrify)
-        self.app.add_subcommand('unpetrify', self.unpetrify)
+        self.app.add_subcommand('old-unpetrify', self.unpetrify)
         self.app.add_subcommand(
             'tag', self.tag, arg_synopsis='TAG-NAME -- [GIT-COMMIT-ARG...]')
         self.app.add_subcommand('build', self.build,
diff --git a/tests.branching/petrify.script b/tests.branching/petrify.script
index 3134ab66..fed8e965 100755
--- a/tests.branching/petrify.script
+++ b/tests.branching/petrify.script
@@ -32,7 +32,7 @@ git push --quiet origin HEAD
 "$SRCDIR/scripts/test-morph" edit hello-system hello-stratum goodbye
 (cd ../test:goodbye && git push --quiet origin HEAD)
 
-"$SRCDIR/scripts/test-morph" old-petrify
+"$SRCDIR/scripts/test-morph" petrify
 echo "Petrified:"
 cat hello-stratum.morph