BrotliDecompressionSource: don't bail out too early

If we've consumed the entire input, that doesn't actually mean we're
done decompressing - there might be more output left. This worked (?)
in most cases because the input and output sizes are pretty comparable,
but sometimes they're not and then things get very funny.

Change-Id: I73435a654a911b8ce25119f713b80706c5783c1b

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/unit/libutil/compression.cc b/tests/unit/libutil/compression.cc
index 0542e7d33..3b40db0cd 100644
--- a/tests/unit/libutil/compression.cc
+++ b/tests/unit/libutil/compression.cc
@@ -66,6 +66,16 @@ namespace nix {
         ASSERT_THROW(decompress(method, str), CompressionError);
     }
 
+    TEST(decompress, veryLongBrotli) {
+        auto method = "br";
+        auto str = std::string(65536, 'a');
+        auto o = decompress(method, compress(method, str));
+
+        // This is just to not print 64k of "a" for most failures
+        ASSERT_EQ(o.length(), str.length());
+        ASSERT_EQ(o, str);
+    }
+
     /* ----------------------------------------------------------------------------
      * compression sinks
      * --------------------------------------------------------------------------*/