Add test for partial decompression

tests/decompress_chunk.rs

@@ -0,0 +1,42 @@
+#[test]
+fn deflate_decoder_partial() {
+    let input = vec![
+        210, 82, 8, 12, 245, 15, 113, 12, 242, 247, 15, 81, 240, 244, 115, 242, 143, 80, 80, 10,
+        45, 78, 45, 82, 40, 44, 205, 47, 73, 84, 226, 229, 210, 130, 200, 163, 136, 42, 104, 4,
+        135, 248, 7, 57, 186, 187, 42, 152, 155, 41, 24, 27, 152, 27, 25, 24, 104, 242, 114, 57,
+        26, 24, 24, 24, 42, 248, 123, 43, 184, 167, 150, 128, 213, 21, 229, 231, 151, 40, 36, 231,
+        231, 22, 228, 164, 150, 164, 166, 40, 104, 24, 232, 129, 20, 104, 43, 128, 104, 3, 133,
+        226, 212, 228, 98, 77, 61, 94, 46, 0, 0, 0, 0, 255, 255,
+    ];
+    let expected_output = b"* QUOTAROOT INBOX \"User quota\"\r\n* QUOTA \"User quota\" (STORAGE 76 307200)\r\nA0001 OK Getquotaroot completed (0.001 + 0.000 secs).\r\n";
+
+    // Create very small output buffer.
+    let mut output_buf = [0; 8];
+    let mut output: Vec<u8> = Vec::new();
+
+    let zlib_header = false;
+    let mut decompress = flate2::Decompress::new(zlib_header);
+
+    let flush_decompress = flate2::FlushDecompress::None;
+    loop {
+        let prev_out = decompress.total_out();
+        let status = decompress
+            .decompress(
+                &input[decompress.total_in() as usize..],
+                &mut output_buf,
+                flush_decompress,
+            )
+            .unwrap();
+        let output_len = decompress.total_out() - prev_out;
+        output.extend_from_slice(&output_buf[..output_len as usize]);
+
+        // IMAP stream never ends.
+        assert_ne!(status, flate2::Status::StreamEnd);
+
+        if status == flate2::Status::BufError && output_len == 0 {
+            break;
+        }
+    }
+
+    assert_eq!(output.as_slice(), expected_output);
+}