+static size_t
+split_long_name (const char *name, size_t length)
+{
+ size_t i;
+
+ if (length > PREFIX_FIELD_SIZE)
+ length = PREFIX_FIELD_SIZE+2;
+ for (i = length - 1; i > 0; i--)
+ if (ISSLASH (name[i]))
+ break;
+ return i;
+}
+
+static union block *
+write_ustar_long_name (const char *name)
+{
+ size_t length = strlen (name);
+ size_t i;
+ union block *header;
+
+ if (length > PREFIX_FIELD_SIZE + NAME_FIELD_SIZE + 1)
+ {
+ WARN ((0, 0, _("%s: file name is too long (max %d); not dumped"),
+ quotearg_colon (name),
+ PREFIX_FIELD_SIZE + NAME_FIELD_SIZE + 1));
+ return NULL;
+ }
+
+ i = split_long_name (name, length);
+ if (i == 0)
+ {
+ WARN ((0, 0,
+ _("%s: file name is too long (cannot be split); not dumped"),
+ quotearg_colon (name),
+ PREFIX_FIELD_SIZE + NAME_FIELD_SIZE + 1));
+ return NULL;
+ }
+
+ header = find_next_block ();
+ memset (header->buffer, 0, sizeof (header->buffer));
+ memcpy (header->header.prefix, name, i);
+ memcpy (header->header.name, name + i + 1, length - i);
+
+ return header;
+}
+