Merge branch 'jk/no-null-sha1-in-cache-tree'

Code to update the cache-tree has been tightened so that we won't
accidentally write out any 0{40} entry in the tree object.

* jk/no-null-sha1-in-cache-tree:
  cache-tree: reject entries with null sha1

2 files changed, 28 insertions, 0 deletions

diff --git a/t/t1601-index-bogus.sh b/t/t1601-index-bogus.sh
new file mode 100755
index 0000000000..73cc9323cd
--- /dev/null
+++ b/t/t1601-index-bogus.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+test_description='test handling of bogus index entries'
+. ./test-lib.sh
+
+test_expect_success 'create tree with null sha1' '
+	tree=$(printf "160000 commit $_z40\\tbroken\\n" | git mktree)
+'
+
+test_expect_success 'read-tree refuses to read null sha1' '
+	test_must_fail git read-tree $tree
+'
+
+test_expect_success 'GIT_ALLOW_NULL_SHA1 overrides refusal' '
+	GIT_ALLOW_NULL_SHA1=1 git read-tree $tree
+'
+
+test_expect_success 'git write-tree refuses to write null sha1' '
+	test_must_fail git write-tree
+'
+
+test_done
diff --git a/t/t7009-filter-branch-null-sha1.sh b/t/t7009-filter-branch-null-sha1.sh
index c27f90f285..a8d9ec4987 100755
--- a/t/t7009-filter-branch-null-sha1.sh
+++ b/t/t7009-filter-branch-null-sha1.sh
@@ -31,6 +31,12 @@ test_expect_success 'setup: bring HEAD and index in sync' '
 	git commit -a -m "back to normal"
 '
 
+test_expect_success 'noop filter-branch complains' '
+	test_must_fail git filter-branch \
+		--force --prune-empty \
+		--index-filter "true"
+'
+
 test_expect_success 'filter commands are still checked' '
 	test_must_fail git filter-branch \
 		--force --prune-empty \