From 5382e0fc1f5c30532b5b2b322601c9d4a8d4f982 Mon Sep 17 00:00:00 2001
From: Neels Hofmeyr <nhofmeyr@sysmocom.de>
Date: Sun, 26 Mar 2017 23:39:44 +0200
Subject: [PATCH] bitcomp test: fix: also verify bits after decoded data

Before this, the expected data had seemingly random bits set after the end of
the expected decoding result. Make the test expect these extra bits as zero,
matching with the buffer initialization to zero.

In result_matches(), compare the full length of bytes instead of masking the
bits after the end of the decoded data (which caused us to not catch the wrong
expectation until now).

This fixes the underlying issues found in
http://lists.osmocom.org/pipermail/osmocom-net-gprs/2017-March/000876.html
  [osmo-pcu 0.2.896-0a8f] testsuite: 4 failed
  from: Arnaud ZANETTI
  on: Fri Mar 24 09:53:53 UTC 2017

Change-Id: I2501208e2f8b4f709efbcadbd1057c086472c9e6
---
 tests/bitcomp/BitcompTest.cpp | 17 +++--------------
 tests/bitcomp/BitcompTest.err |  4 ++--
 2 files changed, 5 insertions(+), 16 deletions(-)

diff --git a/tests/bitcomp/BitcompTest.cpp b/tests/bitcomp/BitcompTest.cpp
index f35d6bec..c5fde2ea 100644
--- a/tests/bitcomp/BitcompTest.cpp
+++ b/tests/bitcomp/BitcompTest.cpp
@@ -38,7 +38,7 @@ struct test_data {
 			.ucmp_data = {
 			0xff, 0xff, 0xff, 0xf8, 0x00, 0x00, 0x01, 0xff, 0xff,
 			0xff, 0xf8, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xfe,
-			0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xdb
+			0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xc0
 			},
 			.ucmp_len = 194, .verify = 1
 		},
@@ -49,7 +49,7 @@ struct test_data {
 			.ucmp_data = {
 			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x00,
 			0x00, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xf8,
-			0x00, 0x00, 0x00, 0x00, 0x03
+			0x00, 0x00, 0x00, 0x00, 0x00
 			},
 			.ucmp_len = 182, .verify = 1
 		},
@@ -127,18 +127,7 @@ bool result_matches(const bitvec &bits, const uint8_t *exp_data, unsigned int ex
 {
 	if (bits.cur_bit != exp_len)
 		return false;
-	size_t n = (exp_len / 8);
-	int rem = (exp_len % 8);
-
-	if (memcmp(exp_data, bits.data, n) == 0) {
-		if (rem == 0)
-			return true;
-		if ((bits.data[n] & MASK(rem)) == ((*(exp_data + n)) & MASK(rem)))
-			return true;
-		else
-			return false;
-	} else
-		return false;
+	return (memcmp(exp_data, bits.data, CEIL_DIV_8(exp_len)) == 0);
 }
 
 /*  To test decoding of compressed bitmap by Tree based method
diff --git a/tests/bitcomp/BitcompTest.err b/tests/bitcomp/BitcompTest.err
index f769daa4..1d6fb002 100644
--- a/tests/bitcomp/BitcompTest.err
+++ b/tests/bitcomp/BitcompTest.err
@@ -11,7 +11,7 @@ Run_length = 31
 Run_length = 19
 Run_length = 32
 
-expected data = ff ff ff f8 00 00 01 ff ff ff f8 00 00 00 ff ff ff fe 00 00 3f ff ff ff db 
+expected data = ff ff ff f8 00 00 01 ff ff ff f8 00 00 00 ff ff ff fe 00 00 3f ff ff ff c0 
 expected len = 194
 decoded data = ff ff ff f8 00 00 01 ff ff ff f8 00 00 00 ff ff ff fe 00 00 3f ff ff ff c0 
 decoded len = 194
@@ -25,7 +25,7 @@ Run_length = 40
 Run_length = 51
 Run_length = 41
 
-expected data = ff ff ff ff ff ff c0 00 00 00 00 3f ff ff ff ff ff f8 00 00 00 00 03 
+expected data = ff ff ff ff ff ff c0 00 00 00 00 3f ff ff ff ff ff f8 00 00 00 00 00 
 expected len = 182
 decoded data = ff ff ff ff ff ff c0 00 00 00 00 3f ff ff ff ff ff f8 00 00 00 00 00 
 decoded len = 182