1 files changed, 52 insertions, 0 deletions
diff --git a/src/Common/libzip/zip_source_accept_empty.c b/src/Common/libzip/zip_source_accept_empty.c
new file mode 100644
index 00000000..e6d51516
--- /dev/null
+++ b/src/Common/libzip/zip_source_accept_empty.c
@@ -0,0 +1,52 @@
+/*
+  zip_source_accept_empty.c -- if empty source is a valid archive
+  Copyright (C) 2019 Dieter Baron and Thomas Klausner
+
+  This file is part of libzip, a library to manipulate ZIP archives.
+  The authors can be contacted at <libzip@nih.at>
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in
+     the documentation and/or other materials provided with the
+     distribution.
+  3. The names of the authors may not be used to endorse or promote
+     products derived from this software without specific prior
+     written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
+  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include "zipint.h"
+
+
+bool
+zip_source_accept_empty(zip_source_t *src) {
+    int ret;
+
+    if ((zip_source_supports(src) & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_ACCEPT_EMPTY)) == 0) {
+	if (ZIP_SOURCE_IS_LAYERED(src)) {
+	    return zip_source_accept_empty(src->src);
+	}
+	return true;
+    }
+
+    ret = (int)_zip_source_call(src, NULL, 0, ZIP_SOURCE_ACCEPT_EMPTY);
+
+    return ret != 0;
+}