diff --git a/mercurial/copies.py b/mercurial/copies.py
--- a/mercurial/copies.py
+++ b/mercurial/copies.py
@@ -810,10 +810,11 @@
         # of the function is much faster (and is required for carrying copy
         # metadata across the rebase anyway).
         exclude = pathcopies(repo[fromrev], repo[skiprev])
+    pctx = wctx.p1()
     for dst, src in pycompat.iteritems(pathcopies(repo[fromrev], repo[rev])):
         if dst in exclude:
             continue
-        if dst in wctx:
+        if dst in wctx and dst not in pctx:
             wctx[dst].markcopied(src)
 
 
diff --git a/tests/test-graft.t b/tests/test-graft.t
--- a/tests/test-graft.t
+++ b/tests/test-graft.t
@@ -500,7 +500,7 @@
 Graft with --log
 
   $ hg up -Cq 1
-  $ hg graft 3 --log -u foo
+  $ hg graft 3 --log -u foo --config ui.allowemptycommit=yes
   grafting 3:4c60f11aa304 "3"
   warning: can't find ancestor for 'c' copied from 'b'!
   $ hg log --template '{rev}:{node|short} {parents} {desc}\n' -r tip
@@ -752,7 +752,7 @@
   summary:     2
   
 ... grafts of grafts unfortunately can't
-  $ hg graft -q 13 --debug
+  $ hg graft -q 13 --debug --config ui.allowemptycommit=yes
   scanning for duplicate grafts
   grafting 13:7a4785234d87 "2"
     all copies found (* = to merge, ! = divergent, % = renamed and deleted):
@@ -762,10 +762,7 @@
    branchmerge: True, force: True, partial: False
    ancestor: b592ea63bb0c, local: 7e61b508e709+, remote: 7a4785234d87
   starting 4 threads for background file closing (?)
-  committing files:
-  b
-  warning: can't find ancestor for 'b' copied from 'a'!
-  reusing manifest from p1 (listed files actually unchanged)
+  reusing manifest from p1 (no file change)
   committing changelog
   updating the branch cache
   $ hg log -r 'destination(13)'
@@ -808,30 +805,27 @@
 
 graft works on complex revset
 
-  $ hg graft 'origin(13) or destination(origin(13))'
+  $ hg graft 'origin(13) or destination(origin(13))' \
+  > --config ui.allowemptycommit=yes
   skipping ancestor revision 21:7e61b508e709
   skipping ancestor revision 22:3a4e92d81b97
   skipping revision 2:5c095ad7e90f (already grafted to 22:3a4e92d81b97)
   grafting 7:ef0ef43d49e7 "2"
-  warning: can't find ancestor for 'b' copied from 'a'!
   grafting 13:7a4785234d87 "2"
-  warning: can't find ancestor for 'b' copied from 'a'!
   grafting 19:9627f653b421 "2"
   merging b
-  warning: can't find ancestor for 'b' copied from 'a'!
 
 graft with --force (still doesn't graft merges)
 
-  $ hg graft 19 0 6
+  $ hg graft 19 0 6 --config ui.allowemptycommit=yes
   skipping ungraftable merge revision 6
   skipping ancestor revision 0:68795b066622
   skipping already grafted revision 19:9627f653b421 (22:3a4e92d81b97 also has origin 2:5c095ad7e90f)
   [255]
-  $ hg graft 19 0 6 --force
+  $ hg graft 19 0 6 --force --config ui.allowemptycommit=yes
   skipping ungraftable merge revision 6
   grafting 19:9627f653b421 "2"
   merging b
-  warning: can't find ancestor for 'b' copied from 'a'!
   grafting 0:68795b066622 "0"
 
 graft --force after backout
@@ -1046,11 +1040,11 @@
 two renames actually converge to the same name (thus no actual divergence).
 
   $ hg up -q 'desc("A0")'
-  $ HGEDITOR="echo C1 >" hg graft -r 'desc("C0")' --edit
+  $ HGEDITOR="echo C1 >" hg graft -r 'desc("C0")' --edit \
+  > --config ui.allowemptycommit=yes
   grafting 2:f58c7e2b28fa "C0"
   merging f1a and f1b to f1a
   merging f5a
-  warning: can't find ancestor for 'f5a' copied from 'f5b'!
   $ hg status --change .
   M f1a
   M f5a
@@ -1064,7 +1058,8 @@
 
 Test the cases A.0 (f4x) and A.6 (f3x)
 
-  $ HGEDITOR="echo D1 >" hg graft -r 'desc("D0")' --edit
+  $ HGEDITOR="echo D1 >" hg graft -r 'desc("D0")' --edit \
+  > --config ui.allowemptycommit=yes
   grafting 3:b69f5839d2d9 "D0"
   note: possible conflict - f3b was renamed multiple times to:
    f3a
@@ -1150,7 +1145,8 @@
 
 Test the cases A.1 (f4x) and A.7 (f3x).
 
-  $ HGEDITOR="echo D2 >" hg graft -r 'desc("D0")' --edit
+  $ HGEDITOR="echo D2 >" hg graft -r 'desc("D0")' --edit \
+  > --config ui.allowemptycommit=yes
   grafting 3:b69f5839d2d9 "D0"
   note: possible conflict - f3b was renamed multiple times to:
    f3d
@@ -1165,7 +1161,8 @@
 
   $ hg up -q "desc("C0")"
 BROKEN: Shouldn't get the warning about missing ancestor
-  $ HGEDITOR="echo E1 >" hg graft -r 'desc("E0")' --edit
+  $ HGEDITOR="echo E1 >" hg graft -r 'desc("E0")' --edit \
+  > --config ui.allowemptycommit=yes
   grafting 6:6bd1736cab86 "E0"
   note: possible conflict - f1a was renamed multiple times to:
    f1b
@@ -1184,7 +1181,8 @@
 
   $ hg up -q "desc("C0")"
 BROKEN: Shouldn't get the warning about missing ancestor
-  $ HGEDITOR="echo F1 >" hg graft -r 'desc("F0")' --edit
+  $ HGEDITOR="echo F1 >" hg graft -r 'desc("F0")' --edit \
+  > --config ui.allowemptycommit=yes
   grafting 7:d376ab0d7fda "F0"
   warning: can't find ancestor for 'f1f' copied from 'f1a'!
 BROKEN: f1f should be marked a copy from f1b
@@ -1200,7 +1198,8 @@
 BROKEN: We should get a merge conflict from the 3-way merge between f1b in C0
 (content "c1c") and f1g in G0 (content "c1g") with f1a in A0 as base (content
 "c1a")
-  $ HGEDITOR="echo G1 >" hg graft -r 'desc("G0")' --edit
+  $ HGEDITOR="echo G1 >" hg graft -r 'desc("G0")' --edit \
+  > --config ui.allowemptycommit=yes
   grafting 8:ba67f08fb15a "G0"
   warning: can't find ancestor for 'f1g' copied from 'f1a'!
 
diff --git a/tests/test-issue1175.t b/tests/test-issue1175.t
--- a/tests/test-issue1175.t
+++ b/tests/test-issue1175.t
@@ -82,7 +82,6 @@
   continue: hg graft --continue
   $ hg graft --continue
   grafting 1:5974126fad84 "b1"
-  warning: can't find ancestor for 'b' copied from 'a'!
   $ hg log -f b -T 'changeset:   {rev}:{node|short}\nsummary:     {desc}\n\n'
   changeset:   3:376d30ccffc0
   summary:     b1