Improve errors when file checks differ.

diff --git a/test/test.cc b/test/test.cc
index 4a1dbf4962419b1a2fb44e24a76108ec125fc158..4c0b8bf8e4c5876b36074dda62afe236a29b52e4 100644 (file)
--- a/test/test.cc
+++ b/test/test.cc
@@ -30,8 +30,10 @@ using std::cerr;
 using std::cout;
 using std::min;
 using std::max;
+using std::hex;
 using std::ifstream;
 using std::getline;
+using std::stringstream;
 
 boost::filesystem::path private_test;
 
@@ -94,15 +96,21 @@ check_file (boost::filesystem::path ref, boost::filesystem::path check)
        uint8_t* ref_buffer = new uint8_t[buffer_size];
        uint8_t* check_buffer = new uint8_t[buffer_size];
 
-       while (N) {
-               uintmax_t this_time = min (uintmax_t (buffer_size), N);
+       uintmax_t offset = 0;
+       while (offset < N) {
+               uintmax_t this_time = min (uintmax_t (buffer_size), N - offset);
                size_t r = fread (ref_buffer, 1, this_time, ref_file);
                BOOST_CHECK_EQUAL (r, this_time);
                r = fread (check_buffer, 1, this_time, check_file);
                BOOST_CHECK_EQUAL (r, this_time);
 
-               BOOST_CHECK_EQUAL (memcmp (ref_buffer, check_buffer, this_time), 0);
-               N -= this_time;
+               for (uintmax_t i = 0; i < this_time; ++i) {
+                       stringstream s;
+                       s << "Files differ at offset " << (offset + i) << "; reference is " << hex << ((int) ref_buffer[i]) << ", check is " << ((int) check_buffer[i]);
+                       BOOST_CHECK_MESSAGE (ref_buffer[i] == check_buffer[i], s.str ());
+               }
+
+               offset += this_time;
        }
 
        delete[] ref_buffer;