gunzip was incorrectly reporting a failed crc and length (discovered by
Chang, Shu-Hao).  The bitbuffer needs to be unwound after decompression,
as it was eating into the crc/size field.
diff --git a/libbb/unzip.c b/libbb/unzip.c
index bb32891..69cc819 100644
--- a/libbb/unzip.c
+++ b/libbb/unzip.c
@@ -875,6 +875,14 @@
 		}
 	} while (!e);
 
+	/* Undo too much lookahead. The next read will be byte aligned so we
+	 * can discard unused bits in the last meaningful byte.
+	 */
+	while (bk >= 8) {
+		bk -= 8;
+		ungetc((bb << bk), in_file);
+	}
+
 	/* flush out window */
 	flush_window();