wireproto: correctly escape batched args and responses (issue4739) This issue appears to be as old as wireproto batching itself: I can reproduce the failure as far back as 08ef6b5f3715 trivially by rebasing the test changes in this patch, which was back in the 1.9 era. I didn't test before that change, because prior to that the testfile has a different name and I'm lazy. Note that the test thought it was checking this case, but it actually wasn't: it put a literal ; in the arg and response for its greet command, but the mangle/unmangle step defined in the test meant that instead of "Fo, =;o" going over the wire, "Gp-!><p" went instead, which doesn't contain any special characters (those being [.=;]) and thus not exercising the escaping. The test has been updated to use pre-unmangled special characters, so the request is now "Fo+<:o", which mangles to "Gp,=;p". I have confirmed that the test fails without the adjustment to the escaping rules in wireproto.py. No existing clients of RPC batching were depending on the old behavior in any way. The only *actual* users of batchable RPCs in core were: 1) largefiles, wherein it batches up many statlfile calls. It sends hexlified hashes over the wire and gets a 0, 1, or 2 back as a response. No risk of special characters. 2) setdiscovery, which was using heads() and known(), both of which communicate via hexlified nodes. Again, no risk of special characters. Since the escaping functionality has been completely broken since it was introduced, we know that it has no users. As such, we can change the escaping mechanism without having to worry about backwards compatibility issues. For the curious, this was detected by chance: it happens that the lz4-compressed text of a test file for remotefilelog compressed to something containing a ;, which then caused the failure when I moved remotefilelog to using batching for file content fetching.

DOCUMENT_ROOT="/var/www/hg"; export DOCUMENT_ROOT
GATEWAY_INTERFACE="CGI/1.1"; export GATEWAY_INTERFACE
HTTP_ACCEPT="text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"; export HTTP_ACCEPT
HTTP_ACCEPT_CHARSET="ISO-8859-1,utf-8;q=0.7,*;q=0.7"; export HTTP_ACCEPT_CHARSET
HTTP_ACCEPT_ENCODING="gzip,deflate"; export HTTP_ACCEPT_ENCODING
HTTP_ACCEPT_LANGUAGE="en-us,en;q=0.5"; export HTTP_ACCEPT_LANGUAGE
HTTP_CACHE_CONTROL="max-age=0"; export HTTP_CACHE_CONTROL
HTTP_CONNECTION="keep-alive"; export HTTP_CONNECTION
HTTP_HOST="hg.omnifarious.org"; export HTTP_HOST
HTTP_KEEP_ALIVE="300"; export HTTP_KEEP_ALIVE
HTTP_USER_AGENT="Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.0.4) Gecko/20060608 Ubuntu/dapper-security Firefox/1.5.0.4"; export HTTP_USER_AGENT
PATH_INFO="/"; export PATH_INFO
PATH_TRANSLATED="/var/www/hg/index.html"; export PATH_TRANSLATED
QUERY_STRING=""; export QUERY_STRING
REMOTE_ADDR="127.0.0.2"; export REMOTE_ADDR
REMOTE_PORT="44703"; export REMOTE_PORT
REQUEST_METHOD="GET"; export REQUEST_METHOD
REQUEST_URI="/test/"; export REQUEST_URI
SCRIPT_FILENAME="/home/hopper/hg_public/test.cgi"; export SCRIPT_FILENAME
SCRIPT_NAME="/test"; export SCRIPT_NAME
SCRIPT_URI="http://hg.omnifarious.org/test/"; export SCRIPT_URI
SCRIPT_URL="/test/"; export SCRIPT_URL
SERVER_ADDR="127.0.0.1"; export SERVER_ADDR
SERVER_ADMIN="eric@localhost"; export SERVER_ADMIN
SERVER_NAME="hg.omnifarious.org"; export SERVER_NAME
SERVER_PORT="80"; export SERVER_PORT
SERVER_PROTOCOL="HTTP/1.1"; export SERVER_PROTOCOL
SERVER_SIGNATURE="<address>Apache/2.0.53 (Fedora) Server at hg.omnifarious.org Port 80</address>"; export SERVER_SIGNATURE
SERVER_SOFTWARE="Apache/2.0.53 (Fedora)"; export SERVER_SOFTWARE