diff --git a/tests/test-push-warn b/tests/test-push-warn
--- a/tests/test-push-warn
+++ b/tests/test-push-warn
@@ -264,4 +264,40 @@ hg out inner --template "{rev}: {branche
 hg push inner
 cd ..
 
+echo % check prepush with new branch head and new child of former branch head
+echo % but child is on different branch
+hg init p
+cd p
+hg branch A
+echo a0 >a
+hg ci -Ama0
+echo a1 >a
+hg ci -ma1
+hg up null
+hg branch B
+echo b0 >b
+hg ci -Amb0
+echo b1 >b
+hg ci -mb1
+
+hg clone . inner
+
+hg up A
+hg branch -f B
+echo a3 >a
+hg ci -ma3
+hg up 3
+hg branch -f A
+echo b3 >b
+hg ci -mb3
+
+echo %% glog of local
+hg glog --template "{rev}: {branches} {desc}\n"
+echo %% glog of remote
+hg glog -R inner --template "{rev}: {branches} {desc}\n"
+echo %% outgoing
+hg out inner --template "{rev}: {branches} {desc}\n"
+hg push inner
+cd ..
+
 exit 0
diff --git a/tests/test-push-warn.out b/tests/test-push-warn.out
--- a/tests/test-push-warn.out
+++ b/tests/test-push-warn.out
@@ -258,3 +258,48 @@ adding changesets
 adding manifests
 adding file changes
 added 1 changesets with 1 changes to 1 files
+% check prepush with new branch head and new child of former branch head
+% but child is on different branch
+marked working directory as branch A
+adding a
+0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+marked working directory as branch B
+adding b
+created new head
+updating to branch B
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+marked working directory as branch B
+1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+marked working directory as branch A
+%% glog of local
+@  5: A b3
+|
+| o  4: B a3
+| |
+o |  3: B b1
+| |
+o |  2: B b0
+ /
+o  1: A a1
+|
+o  0: A a0
+
+%% glog of remote
+@  3: B b1
+|
+o  2: B b0
+
+o  1: A a1
+|
+o  0: A a0
+
+%% outgoing
+comparing with inner
+searching for changes
+4: B a3
+5: A b3
+pushing to inner
+searching for changes
+abort: push creates new remote heads on branch 'A'!
+(did you forget to merge? use push -f to force)