Pull didn't fail on history disconnect

set +o pipefail caused git to merge two branches without a common
history instead of failing.

Author: admorgan

lib/git-subrepo

@@ -1787,9 +1787,7 @@ git:get-head-branch-commit() {
 git:commit-in-rev-list() {
   local commit=$1
   local list_head=$2
-  set +o pipefail
   git rev-list "$list_head" | grep -q "^$commit"
-  set -o pipefail
 }
 
 git:make-ref() {

test/pull.t

@@ -88,12 +88,11 @@ gitrepo=$OWNER/foo/bar/.gitrepo
   git subrepo pull bar || touch pull_failed
 ) &> /dev/null || die
 
-# XXX
-# # We check that the control file was created
-# {
-#   test-exists \
-#     "$OWNER/foo/pull_failed"
-# }
+# We check that the control file was created
+{
+  test-exists \
+    "$OWNER/foo/pull_failed"
+}
 
 done_testing # 9