--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libzip/lib/zip_file_set_comment.c	Wed Feb 24 21:19:28 2016 +0100
@@ -0,0 +1,103 @@
+/*
+  zip_file_set_comment.c -- set comment for file in archive
+  Copyright (C) 2006-2014 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 <stdlib.h>
+
+#include "zipint.h"
+
+
+ZIP_EXTERN int
+zip_file_set_comment(zip_t *za, zip_uint64_t idx,
+		     const char *comment, zip_uint16_t len, zip_flags_t flags)
+{
+    zip_entry_t *e;
+    zip_string_t *cstr;
+    int changed;
+
+    if (_zip_get_dirent(za, idx, 0, NULL) == NULL)
+	return -1;
+
+    if (ZIP_IS_RDONLY(za)) {
+	zip_error_set(&za->error, ZIP_ER_RDONLY, 0);
+	return -1;
+    }
+
+    if (len > 0 && comment == NULL) {
+	zip_error_set(&za->error, ZIP_ER_INVAL, 0);
+	return -1;
+    }
+
+    if (len > 0) {
+	if ((cstr=_zip_string_new((const zip_uint8_t *)comment, len, flags, &za->error)) == NULL)
+	    return -1;
+	if ((flags & ZIP_FL_ENCODING_ALL) == ZIP_FL_ENC_GUESS && _zip_guess_encoding(cstr, ZIP_ENCODING_UNKNOWN) == ZIP_ENCODING_UTF8_GUESSED)
+	    cstr->encoding = ZIP_ENCODING_UTF8_KNOWN;
+    }
+    else
+	cstr = NULL;
+
+    e = za->entry+idx;
+
+    if (e->changes) {
+	_zip_string_free(e->changes->comment);
+	e->changes->comment = NULL;
+	e->changes->changed &= ~ZIP_DIRENT_COMMENT;
+    }
+
+    if (e->orig && e->orig->comment)
+	changed = !_zip_string_equal(e->orig->comment, cstr);
+    else
+	changed = (cstr != NULL);
+	
+    if (changed) {
+        if (e->changes == NULL) {
+            if ((e->changes=_zip_dirent_clone(e->orig)) == NULL) {
+                zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
+		_zip_string_free(cstr);
+                return -1;
+            }
+        }
+        e->changes->comment = cstr;
+        e->changes->changed |= ZIP_DIRENT_COMMENT;
+    }
+    else {
+	_zip_string_free(cstr);
+	if (e->changes && e->changes->changed == 0) {
+	    _zip_dirent_free(e->changes);
+	    e->changes = NULL;
+	}
+    }
+
+    return 0;
+}