Fix bugs in lzma_index_read() and lzma_index_cat().

lzma_index_read() didn't skip over Stream Padding
if it was the first record in the Index.

lzma_index_cat() didn't combine small Indexes correctly.

The test suite was updated to check for these bugs.

These bugs didn't affect the xz command line tool or
most users of liblzma in any way.

1 files changed, 25 insertions, 3 deletions

diff --git a/tests/test_index.c b/tests/test_index.c
index 5ce2c524..b98b6c16 100644
--- a/tests/test_index.c
+++ b/tests/test_index.c
@@ -14,6 +14,9 @@
 
 #define MEMLIMIT (LZMA_VLI_C(1) << 20)
 
+#define SMALL_COUNT 3
+#define BIG_COUNT 5555
+
 
 static lzma_index *
 create_empty(void)
@@ -46,9 +49,8 @@ create_big(void)
 	lzma_vli uncompressed_size = 0;
 
 	// Add pseudo-random sizes (but always the same size values).
-	const size_t count = 5555;
 	uint32_t n = 11;
-	for (size_t j = 0; j < count; ++j) {
+	for (size_t j = 0; j < BIG_COUNT; ++j) {
 		n = 7019 * n + 7607;
 		const uint32_t t = n * 3011;
 		expect(lzma_index_append(i, NULL, t, n) == LZMA_OK);
@@ -56,7 +58,7 @@ create_big(void)
 		uncompressed_size += n;
 	}
 
-	expect(lzma_index_count(i) == count);
+	expect(lzma_index_count(i) == BIG_COUNT);
 	expect(lzma_index_total_size(i) == total_size);
 	expect(lzma_index_uncompressed_size(i) == uncompressed_size);
 	expect(lzma_index_total_size(i) + lzma_index_size(i)
@@ -166,6 +168,7 @@ test_code(lzma_index *i)
 	// Decode
 	lzma_index *d;
 	expect(lzma_index_decoder(&strm, &d, MEMLIMIT) == LZMA_OK);
+	expect(d == NULL);
 	succeed(decoder_loop(&strm, buf, index_size));
 
 	expect(lzma_index_equal(i, d));
@@ -231,6 +234,7 @@ static void
 test_cat(void)
 {
 	lzma_index *a, *b, *c;
+	lzma_index_record r;
 
 	// Empty Indexes
 	a = create_empty();
@@ -240,6 +244,7 @@ test_cat(void)
 	expect(lzma_index_stream_size(a) == 2 * LZMA_STREAM_HEADER_SIZE + 8);
 	expect(lzma_index_file_size(a)
 			== 2 * (2 * LZMA_STREAM_HEADER_SIZE + 8));
+	expect(lzma_index_read(a, &r));
 
 	b = create_empty();
 	expect(lzma_index_cat(a, b, NULL, 0) == LZMA_OK);
@@ -262,6 +267,9 @@ test_cat(void)
 	expect(lzma_index_file_size(a)
 			== 5 * (2 * LZMA_STREAM_HEADER_SIZE + 8) + 4 + 8);
 
+	expect(lzma_index_read(a, &r));
+	lzma_index_rewind(a);
+	expect(lzma_index_read(a, &r));
 	lzma_index_end(a, NULL);
 
 	// Small Indexes
@@ -279,8 +287,19 @@ test_cat(void)
 	expect(lzma_index_cat(a, b, NULL, 12) == LZMA_OK);
 	expect(lzma_index_file_size(a) == stream_size * 4 + 4 + 8 + 12);
 
+	expect(lzma_index_count(a) == SMALL_COUNT * 4);
+	for (int i = SMALL_COUNT * 4; i >= 0; --i)
+		expect(!lzma_index_read(a, &r) ^ (i == 0));
+
 	lzma_index_end(a, NULL);
 
+	// Mix of empty and small
+	a = create_empty();
+	b = create_small();
+	expect(lzma_index_cat(a, b, NULL, 4) == LZMA_OK);
+	for (int i = SMALL_COUNT; i >= 0; --i)
+		expect(!lzma_index_read(a, &r) ^ (i == 0));
+
 	// Big Indexes
 	a = create_big();
 	stream_size = lzma_index_stream_size(a);
@@ -296,6 +315,9 @@ test_cat(void)
 	expect(lzma_index_cat(a, b, NULL, 12) == LZMA_OK);
 	expect(lzma_index_file_size(a) == stream_size * 4 + 4 + 8 + 12);
 
+	for (int i = BIG_COUNT * 4; i >= 0; --i)
+		expect(!lzma_index_read(a, &r) ^ (i == 0));
+
 	lzma_index_end(a, NULL);
 }