t: add basic tests for our SHA-1 implementation

We have in the past had some unfortunate endianness issues with some
SHA-1 implementations we ship, especially on big-endian machines.  Add
an explicit test using the test helper to catch these issues and point
them out prominently.  This test can also be used as a staging ground
for people testing additional algorithms to verify that their
implementations are working as expected.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0015-hash.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+test_description='test basic hash implementation'
+. ./test-lib.sh
+
+
+test_expect_success 'test basic SHA-1 hash values' '
+	test-tool sha1 </dev/null >actual &&
+	grep da39a3ee5e6b4b0d3255bfef95601890afd80709 actual &&
+	printf "a" | test-tool sha1 >actual &&
+	grep 86f7e437faa5a7fce15d1ddcb9eaeaea377667b8 actual &&
+	printf "abc" | test-tool sha1 >actual &&
+	grep a9993e364706816aba3e25717850c26c9cd0d89d actual &&
+	printf "message digest" | test-tool sha1 >actual &&
+	grep c12252ceda8be8994d5fa0290a47231c1d16aae3 actual &&
+	printf "abcdefghijklmnopqrstuvwxyz" | test-tool sha1 >actual &&
+	grep 32d10c7b8cf96570ca04ce37f2a19d84240d3a89 actual &&
+	perl -e "$| = 1; print q{aaaaaaaaaa} for 1..100000;" | \
+		test-tool sha1 >actual &&
+	grep 34aa973cd4c4daa4f61eeb2bdbad27316534016f actual &&
+	printf "blob 0\0" | test-tool sha1 >actual &&
+	grep e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 actual &&
+	printf "blob 3\0abc" | test-tool sha1 >actual &&
+	grep f2ba8f84ab5c1bce84a7b441cb1959cfc7093b7f actual &&
+	printf "tree 0\0" | test-tool sha1 >actual &&
+	grep 4b825dc642cb6eb9a060e54bf8d69288fbee4904 actual
+'
+
+test_done