Sync with v2.16.1

* maint:
  Git 2.16.1
  t5601-clone: test case-conflicting files on case-insensitive filesystem
  repository: pre-initialize hash algo pointer

Documentation/RelNotes/2.16.1.txt

@@ -0,0 +1,11 @@
+Git v2.16.1 Release Notes
+=========================
+
+Fixes since v2.16
+-----------------
+
+ * "git clone" segfaulted when cloning a project that happens to
+   track two paths that differ only in case on a case insensitive
+   filesystem.
+
+Does not contain any other documentation updates or code clean-ups.

repository.c

@@ -5,7 +5,7 @@
 
 /* The main repository */
 static struct repository the_repo = {
-	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &the_index, NULL, 0, 0
+	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &the_index, &hash_algos[GIT_HASH_SHA1], 0, 0
 };
 struct repository *the_repository = &the_repo;
 

t/t5601-clone.sh

@@ -611,4 +611,21 @@ test_expect_success 'GIT_TRACE_PACKFILE produces a usable pack' '
 	git -C replay.git index-pack -v --stdin <tmp.pack
 '
 
+hex2oct () {
+	perl -ne 'printf "\\%03o", hex for /../g'
+}
+
+test_expect_success 'clone on case-insensitive fs' '
+	git init icasefs &&
+	(
+		cd icasefs
+		o=$(git hash-object -w --stdin </dev/null | hex2oct) &&
+		t=$(printf "100644 X\0${o}100644 x\0${o}" |
+			git hash-object -w -t tree --stdin) &&
+		c=$(git commit-tree -m bogus $t) &&
+		git update-ref refs/heads/bogus $c &&
+		git clone -b bogus . bogus
+	)
+'
+
 test_done