salvaged: properly deal with salvaged file during copy tracing

When salvaged files are encountered, the removal have been reverted and we
should keep the rename information from the other side.

The conditional was starting to be quite hairy, so we spell it out in multiple
elif case for readability.

This fixes the associated test cases introduced a while back. The changeset centric copy tracing is now (known) bug free.

Differential Revision: https://phab.mercurial-scm.org/D9130

mercurial/copies.py

@@ -371,11 +371,15 b' def _merge_copies_dict(minor, major, isa'
                 continue
             # content from "major" wins, unless it is older
             # than the branch point or there is a merge
-            if (
-                new_tt == other_tt
-                or not isancestor(new_tt, other_tt)
-                or dest in changes.merged
-            ):
+            if new_tt == other_tt:
+                minor[dest] = value
+            elif value[1] is None and dest in changes.salvaged:
+                pass
+            elif other[1] is None and dest in changes.salvaged:
+                minor[dest] = value
+            elif not isancestor(new_tt, other_tt):
+                minor[dest] = value
+            elif dest in changes.merged:
                 minor[dest] = value
 
 

tests/test-copies-chain-merge.t

@@ -892,15 +892,15 b' copy tracing chain.'
   o  0 i-0 initial commit: a b h
   
 
-BROKEN: 'a' should be the the source of 'd' in the changeset centric algorithm too
+'a' is the copy source of 'd'
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCGm-0")'
   A d
-    a (filelog !)
+    a (no-compatibility !)
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGCm-0")'
   A d
-    a (filelog !)
+    a (no-compatibility !)
   R a
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCGm-0")'
   A d
@@ -955,17 +955,17 b' copy tracing chain.'
   o  0 i-0 initial commit: a b h
   
 
-BROKEN: 'a' should be the the source of 'd' in the changeset centric algorithm too
+'a' is the the copy source of 'd'
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCB-revert-m-0")'
   M b
   A d
-    a (filelog !)
+    a (no-compatibility !)
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBC-revert-m-0")'
   M b
   A d
-    a (filelog !)
+    a (no-compatibility !)
   R a
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCB-revert-m-0")'
   M b