Issue #1159051: GzipFile now raises EOFError when reading a corrupted file

with truncated header or footer.
Added tests for reading truncated gzip, bzip2, and lzma files.

1 files changed, 14 insertions, 0 deletions

diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 912fac1..df7e18c 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -577,6 +577,20 @@ class BZ2FileTest(BaseTest):
                 bz2f.seek(-150, 1)
                 self.assertEqual(bz2f.read(), self.TEXT[500-150:])
 
+    def test_read_truncated(self):
+        # Drop the eos_magic field (6 bytes) and CRC (4 bytes).
+        truncated = self.DATA[:-10]
+        with BZ2File(BytesIO(truncated)) as f:
+            self.assertRaises(EOFError, f.read)
+        with BZ2File(BytesIO(truncated)) as f:
+            self.assertEqual(f.read(len(self.TEXT)), self.TEXT)
+            self.assertRaises(EOFError, f.read, 1)
+        # Incomplete 4-byte file header, and block header of at least 146 bits.
+        for i in range(22):
+            with BZ2File(BytesIO(truncated[:i])) as f:
+                self.assertRaises(EOFError, f.read, 1)
+
+
 class BZ2CompressorTest(BaseTest):
     def testCompress(self):
         bz2c = BZ2Compressor()