Merge lp:~jelmer/brz/lossless-fetch-optional into lp:brz

[Jelmer Vernooij]

Allow InterBranch formats to raise NoRoundtrippingSupport to indicate
that they can't do lossless conversion between two branches.

Allow InterBranch formats to raise NoRoundtrippingSupport to indicate
that they can't do lossless conversion between two branches.

[Martin Packman (gz)]

Makes sense, thanks.

review: Approve

=== modified file 'breezy/tests/per_branch/test_branch.py'
--- breezy/tests/per_branch/test_branch.py	2018-03-04 02:57:55 +0000
+++ breezy/tests/per_branch/test_branch.py	2018-03-05 21:47:34 +0000
@@ -424,7 +424,12 @@
         branch_a = tree_a.branch
         checkout_b = branch_a.create_checkout('b')
         self.assertEqual('null:', checkout_b.last_revision())
-        rev1 = checkout_b.commit('rev1')
+        try:
+            rev1 = checkout_b.commit('rev1')
+        except errors.NoRoundtrippingSupport:
+            raise tests.TestNotApplicable(
+                    'roundtripping between %r and %r not supported' %
+                    (checkout_b.branch, checkout_b.branch.get_master_branch()))
         self.assertEqual(rev1, branch_a.last_revision())
         self.assertNotEqual(checkout_b.branch.base, branch_a.base)
 
 
=== modified file 'breezy/tests/per_interbranch/test_copy_content_into.py'
--- breezy/tests/per_interbranch/test_copy_content_into.py	2017-05-21 18:10:28 +0000
+++ breezy/tests/per_interbranch/test_copy_content_into.py	2018-03-05 21:47:34 +0000
@@ -17,6 +17,8 @@
 """Tests for breezy.branch.InterBranch.copy_content_into."""
 
 from breezy import branch
+from breezy.errors import NoRoundtrippingSupport
+from breezy.tests import TestNotApplicable
 from breezy.tests.per_interbranch import (
     StubMatchingInter,
     StubWithFormat,
@@ -30,7 +32,12 @@
         self.tree1 = self.make_from_branch_and_tree('tree1')
         rev1 = self.tree1.commit('one')
         branch2 = self.make_to_branch('tree2')
-        branch2.repository.fetch(self.tree1.branch.repository)
+        try:
+            branch2.repository.fetch(self.tree1.branch.repository)
+        except NoRoundtrippingSupport:
+            raise TestNotApplicable(
+                'lossless cross-vcs fetch from %r to %r unsupported' %
+                (self.tree1.branch, branch2))
         self.tree1.branch.copy_content_into(branch2, revision_id=rev1)
 
     def test_inter_is_used(self):
 
=== modified file 'breezy/tests/per_interbranch/test_fetch.py'
--- breezy/tests/per_interbranch/test_fetch.py	2018-02-27 14:36:14 +0000
+++ breezy/tests/per_interbranch/test_fetch.py	2018-03-05 21:47:34 +0000
@@ -16,7 +16,7 @@
 
 """Tests for InterBranch.fetch."""
 
-from breezy.errors import FetchLimitUnsupported
+from breezy.errors import FetchLimitUnsupported, NoRoundtrippingSupport
 from breezy.revision import NULL_REVISION
 from breezy.tests import TestNotApplicable
 from breezy.tests.per_interbranch import (
@@ -35,7 +35,12 @@
         rev1 = wt.commit('lala!', allow_pointless=False)
 
         b2 = self.make_to_branch('b2')
-        b2.fetch(b1)
+        try:
+            b2.fetch(b1)
+        except NoRoundtrippingSupport:
+            raise TestNotApplicable(
+                'lossless cross-vcs fetch %r to %r not supported' %
+                (b1, b2))
 
         # fetch does not update the last revision
         self.assertEqual(NULL_REVISION, b2.last_revision())
@@ -61,6 +66,10 @@
             b2.fetch(b1, limit=1)
         except FetchLimitUnsupported:
             raise TestNotApplicable('interbranch does not support fetch limits')
+        except NoRoundtrippingSupport:
+            raise TestNotApplicable(
+                'lossless cross-vcs fetch %r to %r not supported' %
+                (b1, b2))
 
         # fetch does not update the last revision
         self.assertEqual(NULL_REVISION, b2.last_revision())
@@ -81,6 +90,10 @@
             b2.fetch(b1, limit=1)
         except FetchLimitUnsupported:
             raise TestNotApplicable('interbranch does not support fetch limits')
+        except NoRoundtrippingSupport:
+            raise TestNotApplicable(
+                'lossless cross-vcs fetch %r to %r not supported' %
+                (b1, b2))
 
         self.assertEqual(
             {rev1},