make_bittorrent_peer_connection() used to construct a struct uri on
the stack. This was hacky but worked nicely because the struct uri
was not really accessed after make_connection() returned. However,
since commit a83ff1f565, the struct uri
is also needed when the connection is being closed. Valgrind shows:
Invalid read of size 2
at 0x8100764: get_blacklist_entry (blacklist.c:33)
by 0x8100985: del_blacklist_entry (blacklist.c:64)
by 0x80DA579: complete_connect_socket (socket.c:448)
by 0x80DA84A: connected (socket.c:513)
by 0x80D0DDF: select_loop (select.c:297)
by 0x80D00C6: main (main.c:353)
Address 0xBEC3BFAE is just below the stack ptr. To suppress, use: --workaround-gcc296-bugs=yes
To fix this, allocate the struct uri on the heap instead, by
constructing a string and giving that to get_uri(). This string
cannot use the "bittorrent" URI scheme because parse_uri() does not
recognize the host and port fields in that. (The "bittorrent" scheme
has protocol_backend.free_syntax = 1 in order to support strings like
"bittorrent:http://beta.legaltorrents.com/get/159-noisome-beasts".)
Instead, define a new "bittorrent-peer" URI scheme for this purpose.
If the user attempts to use this URI scheme, its handler aborts the
connection with an error; but when make_bittorrent_peer_connection()
uses a bittorrent-peer URI, the handler is not called.
This change also lets get_uri() set the ipv6 flag if peer_info->ip is
an IPv6 address literal.
Reported by Witold Filipczyk.
Add a boolean protocol flag which says whether "//" in the path
part of an URI can be safely substituted with "/". Be conservative
and enable it only for file://, ftp:// and nntp[s]://. Other
can be turned on later, if needed.
Generalizes the fix from 58b3b1e752.
