compression/tests: calm the static analysts (CID: numerous)

None of our test vectors are 18446744073709551615 bytes long, which
means we can know an `expected_length == returned_length` check will
catch the case where the compression function returns -1 for error. We
know that, but Coverity doesn't.

It's the same thing over and over again, in two different patterns:

>>>     CID 1517301:  Memory - corruptions  (OVERRUN)
>>>     Calling "memcmp" with "original.data" and "original.length" is
suspicious because of the very large index, 18446744073709551615. The index
may be due to a negative parameter being interpreted as unsigned.
393     	if (original.length != decomp_written ||
394     	    memcmp(decompressed.data,
395     		   original.data,
396     		   original.length) != 0) {
397     		debug_message("\033[1;31mgot %zd, expected %zu\033[0m\n",
398     			      decomp_written,

*** CID 1517299:  Memory - corruptions  (OVERRUN)
/lib/compression/tests/test_lzxpress_plain.c: 296 in
test_lzxpress_plain_decompress_more_compressed_files()
290     		debug_start_timer();
291     		written = lzxpress_decompress(p.compressed.data,
292     					      p.compressed.length,
293     					      dest,
294     					      p.decompressed.length);
295     		debug_end_timer("decompress", p.decompressed.length);
>>>     CID 1517299:  Memory - corruptions  (OVERRUN)
>>>     Calling "memcmp" with "p.decompressed.data" and
"p.decompressed.length" is suspicious because of the very large index,
18446744073709551615. The index may be due to a negative parameter being
interpreted as unsigned.
296     		if (written == p.decompressed.length &&
297     		    memcmp(dest, p.decompressed.data, p.decompressed.length)
== 0) {
298     			debug_message("\033[1;32mdecompressed %s!

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Jeremy Allison <jra@samba.org>

2 files changed, 21 insertions, 5 deletions

diff --git a/lib/compression/tests/test_lzx_huffman.c b/lib/compression/tests/test_lzx_huffman.c
index 3a055183f7b..647a01fa3c0 100644
--- a/lib/compression/tests/test_lzx_huffman.c
+++ b/lib/compression/tests/test_lzx_huffman.c
@@ -344,6 +344,7 @@ static void test_lzxpress_huffman_decompress(void **state)
 						      p.compressed.length,
 						      dest,
 						      p.decompressed.length);
+		assert_int_not_equal(written, -1);
 		assert_int_equal(written, p.decompressed.length);
 
 		assert_memory_equal(dest, p.decompressed.data, p.decompressed.length);
@@ -368,6 +369,7 @@ static void test_lzxpress_huffman_compress(void **state)
 							   p.decompressed.length,
 							   &dest);
 
+		assert_int_not_equal(written, -1);
 		assert_int_equal(written, p.compressed.length);
 		assert_memory_equal(dest, p.compressed.data, p.compressed.length);
 		talloc_free(dest);
@@ -444,7 +446,8 @@ static void test_lzxpress_huffman_decompress_files(void **state)
 						      dest,
 						      p.decompressed.length);
 		debug_end_timer("decompress", p.decompressed.length);
-		if (written == p.decompressed.length &&
+		if (written != -1 &&
+		    written == p.decompressed.length &&
 		    memcmp(dest, p.decompressed.data, p.decompressed.length) == 0) {
 			debug_message("\033[1;32mdecompressed %s!\033[0m\n", p.name);
 			score++;
diff --git a/lib/compression/tests/test_lzxpress_plain.c b/lib/compression/tests/test_lzxpress_plain.c
index 17e5a26207b..1264f48530b 100644
--- a/lib/compression/tests/test_lzxpress_plain.c
+++ b/lib/compression/tests/test_lzxpress_plain.c
@@ -294,7 +294,8 @@ static void test_lzxpress_plain_decompress_more_compressed_files(void **state)
 					      dest,
 					      p.decompressed.length);
 		debug_end_timer("decompress", p.decompressed.length);
-		if (written == p.decompressed.length &&
+		if (written != -1 &&
+		    written == p.decompressed.length &&
 		    memcmp(dest, p.decompressed.data, p.decompressed.length) == 0) {
 			debug_message("\033[1;32mdecompressed %s!\033[0m\n", p.name);
 			score++;
@@ -790,7 +791,7 @@ static void test_msft_data1(void **state)
 				   strlen(fixed_data),
 				   out,
 				   talloc_get_size(out));
-
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, sizeof(fixed_out));
 	assert_memory_equal(out, fixed_out, c_size);
 	out2  = talloc_size(tmp_ctx, strlen(fixed_data));
@@ -798,7 +799,7 @@ static void test_msft_data1(void **state)
 				     sizeof(fixed_out),
 				     out2,
 				     talloc_get_size(out2));
-
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, strlen(fixed_data));
 	assert_memory_equal(out2, fixed_data, c_size);
 
@@ -830,7 +831,7 @@ static void test_msft_data2(void **state)
 				   strlen(fixed_data),
 				   out,
 				   talloc_get_size(out));
-
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, sizeof(fixed_out));
 	assert_memory_equal(out, fixed_out, c_size);
 
@@ -840,6 +841,7 @@ static void test_msft_data2(void **state)
 				     out2,
 				     talloc_get_size(out2));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, strlen(fixed_data));
 	assert_memory_equal(out2, fixed_data, c_size);
 
@@ -877,6 +879,7 @@ static void test_lzxpress(void **state)
 				   out,
 				   talloc_get_size(out));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, sizeof(fixed_out));
 	assert_memory_equal(out, fixed_out, c_size);
 
@@ -886,6 +889,7 @@ static void test_lzxpress(void **state)
 				     out2,
 				     talloc_get_size(out2));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, strlen(fixed_data));
 	assert_memory_equal(out2, fixed_data, c_size);
 
@@ -895,6 +899,7 @@ static void test_lzxpress(void **state)
 				     out3,
 				     talloc_get_size(out3));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, strlen(fixed_data));
 	assert_memory_equal(out3, fixed_data, c_size);
 
@@ -927,6 +932,7 @@ static void test_lzxpress2(void **state)
 				   out,
 				   talloc_get_size(out));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, sizeof(fixed_out));
 	assert_memory_equal(out, fixed_out, c_size);
 
@@ -936,6 +942,7 @@ static void test_lzxpress2(void **state)
 				     out2,
 				     talloc_get_size(out2));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, strlen(fixed_data));
 	assert_memory_equal(out2, fixed_data, c_size);
 
@@ -971,6 +978,7 @@ static void test_lzxpress3(void **state)
 				   out,
 				   talloc_get_size(out));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, sizeof(fixed_out));
 	assert_memory_equal(out, fixed_out, c_size);
 
@@ -980,6 +988,7 @@ static void test_lzxpress3(void **state)
 				     out2,
 				     talloc_get_size(out2));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, strlen(fixed_data));
 	assert_memory_equal(out2, fixed_data, c_size);
 
@@ -1015,6 +1024,7 @@ static void test_lzxpress4(void **state)
 				   out,
 				   talloc_get_size(out));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, sizeof(fixed_out));
 	assert_memory_equal(out, fixed_out, c_size);
 
@@ -1024,6 +1034,7 @@ static void test_lzxpress4(void **state)
 				     out2,
 				     talloc_get_size(out2));
 
+	assert_int_not_equal(c_size, -1);
 	assert_int_equal(c_size, strlen(fixed_data));
 	assert_memory_equal(out2, fixed_data, c_size);
 
@@ -1135,6 +1146,7 @@ static void test_lzxpress_round_trip(void **state)
 					data,
 					alloc_size);
 
+		assert_int_not_equal(len, -1);
 		assert_int_equal(len, comp.length);
 
 		assert_memory_equal(comp.data, data, len);
@@ -1144,6 +1156,7 @@ static void test_lzxpress_round_trip(void **state)
 					  data,
 					  alloc_size);
 
+		assert_int_not_equal(len, -1);
 		assert_int_equal(len, uncomp.length);
 
 		assert_memory_equal(uncomp.data, data, len);