LibCompress: Move XZ header validation into the read function

The constructor is now only concerned with creating the required
streams, which means that it no longer fails for XZ streams with
invalid headers. Instead, everything is parsed and validated during the
first read, preparing us for files with multiple streams.

1 files changed, 6 insertions, 4 deletions

diff --git a/Tests/LibCompress/TestXz.cpp b/Tests/LibCompress/TestXz.cpp
index 8bb6af4f01..ec8dc31f1f 100644
--- a/Tests/LibCompress/TestXz.cpp
+++ b/Tests/LibCompress/TestXz.cpp
@@ -118,8 +118,9 @@ TEST_CASE(xz_utils_bad_0_header_magic)
     };
 
     auto stream = MUST(try_make<FixedMemoryStream>(compressed));
-    auto decompressor_or_error = Compress::XzDecompressor::create(move(stream));
-    EXPECT(decompressor_or_error.is_error());
+    auto decompressor = MUST(Compress::XzDecompressor::create(move(stream)));
+    auto buffer_or_error = decompressor->read_until_eof(PAGE_SIZE);
+    EXPECT(buffer_or_error.is_error());
 }
 
 TEST_CASE(xz_utils_bad_0_nonempty_index)
@@ -695,8 +696,9 @@ TEST_CASE(xz_utils_bad_1_stream_flags_2)
     };
 
     auto stream = MUST(try_make<FixedMemoryStream>(compressed));
-    auto decompressor_or_error = Compress::XzDecompressor::create(move(stream));
-    EXPECT(decompressor_or_error.is_error());
+    auto decompressor = MUST(Compress::XzDecompressor::create(move(stream)));
+    auto buffer_or_error = decompressor->read_until_eof(PAGE_SIZE);
+    EXPECT(buffer_or_error.is_error());
 }
 
 TEST_CASE(xz_utils_bad_1_stream_flags_3)