Docs: Fix a bug in xz_pipe_decomp.c example program.

doc/examples/xz_pipe_decomp.c

diff --git a/doc/examples/xz_pipe_decomp.c b/doc/examples/xz_pipe_decomp.c
index d4b204d..fb5ad89 100644
--- a/doc/examples/xz_pipe_decomp.c
+++ b/doc/examples/xz_pipe_decomp.c
@@ -1,7 +1,7 @@
 /*
  * xz_pipe_decomp.c
  * A simple example of pipe-only xz decompressor implementation.
- * version: 2010-07-12 - by Daniel Mealha Cabrita
+ * version: 2012-06-14 - by Daniel Mealha Cabrita
  * Not copyrighted -- provided to the public domain.
  *
  * Compiling:
@@ -101,6 +101,14 @@
 		} while (strm.avail_out == 0);
 	}
 
+	/* Bug fix (2012-06-14): If no errors were detected, check
+	   that the last lzma_code() call returned LZMA_STREAM_END.
+	   If not, the file is probably truncated. */
+	if ((ret == RET_OK) && (ret_xz != LZMA_STREAM_END)) {
+		fprintf (stderr, "Input truncated or corrupt\n");
+		ret = RET_ERROR_DECOMPRESSION;
+	}
+
 	lzma_end (&strm);
 	return ret;
 }