Merge branch 'np/pack'

* np/pack:
  t5300: improve SHA1 collision test
  pack-objects: don't include missing preferred base objects
  sha1write: don't copy full sized buffers

Conflicts:
	t/t5300-pack-object.sh

diff --cc builtin-pack-objects.c
Simple merge

diff --cc t/t5300-pack-object.sh
index 3a0ef8759c9d7a55b95c56ca38cd3c37ac2432fa,8a8b0f1abae5ceeba99eef36a330b6839794145c..b335c6b42de59b9632ff29693c2d7c75dae9794a
--- 1/t/t5300-pack-object.sh
--- 2/t/t5300-pack-object.sh
+++ b/t/t5300-pack-object.sh
@@@ -272,7 -272,8 +272,8 @@@ test_expect_success 
  
  test_expect_success \
      'make sure index-pack detects the SHA1 collision' \
-     'test_must_fail git index-pack -o bad.idx test-3.pack'
 -    'test_must_fail git-index-pack -o bad.idx test-3.pack 2>msg &&
++    'test_must_fail git index-pack -o bad.idx test-3.pack 2>msg &&
+      grep "SHA1 COLLISION FOUND" msg'
  
  test_expect_success \
      'honor pack.packSizeLimit' \