Merge lp:~jelmer/brz/supports-merge-modified into lp:brz

[Jelmer Vernooij]

Add a WorkingTree.supports_merge_modified() method.

Add a WorkingTree.supports_merge_modified() method.

This indicates whether calls to WorkingTree.set_merge_modified() will
raise UnsupportedOperation. This allows e.g. merge to avoid calculating
merge modified hashes if the tree doesn't support them.

[Martin Packman (gz)]

Thanks.

review: Approve

=== modified file 'breezy/merge.py'
--- breezy/merge.py	2018-03-02 01:33:39 +0000
+++ breezy/merge.py	2018-03-19 01:11:01 +0000
@@ -1065,6 +1065,8 @@
         return result
 
     def write_modified(self, results):
+        if not self.working_tree.supports_merge_modified():
+            return
         modified_hashes = {}
         for path in results.modified_paths:
             wt_relpath = self.working_tree.relpath(path)
@@ -1075,10 +1077,7 @@
             if hash is None:
                 continue
             modified_hashes[file_id] = hash
-        try:
-            self.working_tree.set_merge_modified(modified_hashes)
-        except errors.UnsupportedOperation:
-            pass  # Well, whatever.
+        self.working_tree.set_merge_modified(modified_hashes)
 
     @staticmethod
     def parent(entry, file_id):
 
=== modified file 'breezy/tests/per_workingtree/test_workingtree.py'
--- breezy/tests/per_workingtree/test_workingtree.py	2018-03-04 02:57:55 +0000
+++ breezy/tests/per_workingtree/test_workingtree.py	2018-03-19 01:11:01 +0000
@@ -711,17 +711,17 @@
         with tree.lock_write():
             tree.add(['somefile'])
             d = {tree.path2id('somefile'): osutils.sha_string('hello')}
-            try:
+            if tree.supports_merge_modified():
                 tree.set_merge_modified(d)
-            except errors.UnsupportedOperation:
+                mm = tree.merge_modified()
+                self.assertEqual(mm, d)
+            else:
+                self.assertRaises(
+                    errors.UnsupportedOperation,
+                    tree.set_merge_modified, d)
                 mm = tree.merge_modified()
                 self.assertEqual(mm, {})
-                supports_merge_modified = False
-            else:
-                mm = tree.merge_modified()
-                self.assertEqual(mm, d)
-                supports_merge_modified = True
-        if supports_merge_modified:
+        if tree.supports_merge_modified():
             mm = tree.merge_modified()
             self.assertEqual(mm, d)
         else:
 
=== modified file 'breezy/transform.py'
--- breezy/transform.py	2018-03-02 00:50:50 +0000
+++ breezy/transform.py	2018-03-19 01:11:01 +0000
@@ -2859,10 +2859,8 @@
             trace.warning(unicode(conflict))
         pp.next_phase()
         tt.apply()
-        try:
+        if working_tree.supports_merge_modified():
             working_tree.set_merge_modified(merge_modified)
-        except errors.UnsupportedOperation:
-            pass  # well, whatever.
     finally:
         target_tree.unlock()
         tt.finalize()
 
=== modified file 'breezy/workingtree.py'
--- breezy/workingtree.py	2018-03-04 19:11:21 +0000
+++ breezy/workingtree.py	2018-03-19 01:11:01 +0000
@@ -151,6 +151,11 @@
         """See `Tree.has_versioned_directories`."""
         return self._format.supports_versioned_directories
 
+    def supports_merge_modified(self):
+        """Indicate whether this workingtree supports storing merge_modified.
+        """
+        return self._format.supports_merge_modified
+
     def _supports_executable(self):
         if sys.platform == 'win32':
             return False
@@ -1411,6 +1416,9 @@
 
     supports_versioned_directories = None
 
+    supports_merge_modified = True
+    """If this format supports storing merge modified hashes."""
+
     supports_setting_file_ids = True
     """If this format allows setting the file id."""