MorphSet: keep old ref as unpetrify-ref

This makes petrify much simpler, since adding unpetrify-ref is handled
by MorphSet.

This has the side-effect of adding unpetrify-ref when editing, but this
information is also useful for this use-case.

The edit tests now have different diffs and commits, so those have been
updated.

Also, the old merge code currently warns that now there appears to be
petrified changes, since it detects if a branch is petrified by the
presence of the unpetrify-ref field, even though the ref is not a SHA1.

The old code does not handle undoing an edit the new way, so I did not
feel it was worth attempting to comprehend it to fix this bug, which
will be later fixed by the introduction of the new merge code.

3 files changed, 17 insertions, 10 deletions

diff --git a/tests.branching/edit-updates-stratum-build-depends.stdout b/tests.branching/edit-updates-stratum-build-depends.stdout
index 00b303bd..1c6eb8e3 100644
--- a/tests.branching/edit-updates-stratum-build-depends.stdout
+++ b/tests.branching/edit-updates-stratum-build-depends.stdout
@@ -1,46 +1,50 @@
 diff --git a/hello-stratum.morph b/hello-stratum.morph
-index 73ed482..3731d63 100644
+index 73ed482..475fe0f 100644
 --- a/hello-stratum.morph
 +++ b/hello-stratum.morph
-@@ -2,7 +2,7 @@ chunks:
+@@ -2,7 +2,8 @@ chunks:
  - build-depends: []
    build-mode: test
    name: hello
 -  ref: master
 +  ref: newbranch
    repo: test:hello
++  unpetrify-ref: master
  kind: stratum
  name: hello-stratum
 diff --git a/hello-system.morph b/hello-system.morph
-index 721473c..94c1837 100644
+index 721473c..1537f53 100644
 --- a/hello-system.morph
 +++ b/hello-system.morph
-@@ -3,9 +3,8 @@ kind: system
+@@ -3,9 +3,9 @@ kind: system
  name: hello-system
  strata:
  - morph: hello-stratum
 -  ref: master
 +  ref: newbranch
    repo: test:morphs
++  unpetrify-ref: master
  - morph: xyzzy-stratum
    ref: master
    repo: test:morphs
 -system-kind: rootfs-tarball
 diff --git a/xyzzy-stratum.morph b/xyzzy-stratum.morph
-index e302037..97f7208 100644
+index e302037..bcf5b57 100644
 --- a/xyzzy-stratum.morph
 +++ b/xyzzy-stratum.morph
-@@ -1,11 +1,11 @@
+@@ -1,11 +1,13 @@
  build-depends:
  - morph: hello-stratum
 -  ref: master
 +  ref: newbranch
    repo: test:morphs
++  unpetrify-ref: master
  chunks:
  - build-depends: []
    name: hello
 -  ref: master
 +  ref: newbranch
    repo: test:hello
++  unpetrify-ref: master
  kind: stratum
  name: xyzzy-stratum
diff --git a/tests.branching/edit-updates-stratum.stdout b/tests.branching/edit-updates-stratum.stdout
index e84dbe09..32eb820d 100644
--- a/tests.branching/edit-updates-stratum.stdout
+++ b/tests.branching/edit-updates-stratum.stdout
@@ -1,21 +1,22 @@
 diff --git a/hello-stratum.morph b/hello-stratum.morph
-index 73ed482..3731d63 100644
+index 73ed482..475fe0f 100644
 --- a/hello-stratum.morph
 +++ b/hello-stratum.morph
-@@ -2,7 +2,7 @@ chunks:
+@@ -2,7 +2,8 @@ chunks:
  - build-depends: []
    build-mode: test
    name: hello
 -  ref: master
 +  ref: newbranch
    repo: test:hello
++  unpetrify-ref: master
  kind: stratum
  name: hello-stratum
 diff --git a/hello-system.morph b/hello-system.morph
-index b0fed3b..801a955 100644
+index b0fed3b..199c924 100644
 --- a/hello-system.morph
 +++ b/hello-system.morph
-@@ -3,6 +3,5 @@ kind: system
+@@ -3,6 +3,6 @@ kind: system
  name: hello-system
  strata:
  - morph: hello-stratum
@@ -23,3 +24,4 @@ index b0fed3b..801a955 100644
 +  ref: newbranch
    repo: test:morphs
 -system-kind: rootfs-tarball
++  unpetrify-ref: master
diff --git a/tests.branching/workflow.stdout b/tests.branching/workflow.stdout
new file mode 100644
index 00000000..65985486
--- /dev/null
+++ b/tests.branching/workflow.stdout
@@ -0,0 +1 @@
+WARNING: chunk "hello-system.hello-stratum.hello" is now petrified