Commit Graph

242 Commits

Author SHA1 Message Date
Christopher Faulet
fc9cfe4006 REORG: proto_htx: Move HTX analyzers & co to http_ana.{c,h} files
The old module proto_http does not exist anymore. All code dedicated to the HTTP
analysis is now grouped in the file proto_htx.c. So, to finish the polishing
after removing the legacy HTTP code, proto_htx.{c,h} files have been moved in
http_ana.{c,h} files.

In addition, all HTX analyzers and related functions prefixed with "htx_" have
been renamed to start with "http_" instead.
2019-07-19 09:24:12 +02:00
Christopher Faulet
cc76d5b9a1 MINOR: proto_http: Remove the unused flag HTTP_MSGF_WAIT_CONN
This flag is set but never used. So remove it.
2019-07-19 09:24:12 +02:00
Christopher Faulet
711ed6ae4a MAJOR: http: Remove the HTTP legacy code
First of all, all legacy HTTP analyzers and all functions exclusively used by
them were removed. So the most of the functions in proto_http.{c,h} were
removed. Only functions to deal with the HTTP transaction have been kept. Then,
http_msg and hdr_idx modules were entirely removed. And finally the structure
http_msg was lightened of all its useless information about the legacy HTTP. The
structure hdr_ctx was also removed because unused now, just like unused states
in the enum h1_state. Note that the memory pool "hdr_idx" was removed and
"http_txn" is now smaller.
2019-07-19 09:24:12 +02:00
Christopher Faulet
4cb2828e96 MINOR: proxy: Don't adjust connection mode of HTTP proxies anymore
This was only used for the legacy HTTP mode where the connection mode was
handled by the HTTP analyzers. In HTX, the function http_adjust_conn_mode() does
nothing. The connection mode is handled by the muxes.
2019-07-19 09:18:27 +02:00
Christopher Faulet
28b18c5e21 CLEANUP: proxy: Remove the flag PR_O2_USE_HTX
This flag is now unused. So we can safely remove it.
2019-07-19 09:18:27 +02:00
Christopher Faulet
60d29b37b2 MINOR: proxy: Remove tests on the option 'http-use-htx' during H1 upgrade
To know if an upgrade from TCP to H1 must be performed, we now only need to know
if a non HTX stream is assigned to an HTTP backend. So we don't rely anymore on
the flag PR_O2_USE_HTX to handle such upgrades.
2019-07-19 09:18:27 +02:00
Christopher Faulet
c985f6c5d8 MINOR: connection: Remove the multiplexer protocol PROTO_MODE_HTX
Since the legacy HTTP mode is disabled and no multiplexer relies on it anymore,
there is no reason to have 2 multiplexer protocols for the HTTP. So the protocol
PROTO_MODE_HTX was removed and all HTTP multiplexers use now PROTO_MODE_HTTP.
2019-07-19 09:18:27 +02:00
Christopher Faulet
319303739a MAJOR: http: Deprecate and ignore the option "http-use-htx"
From this commit, the legacy HTTP mode is now definitely disabled. It is the
first commit of a long series to remove the legacy HTTP code. Now, all HTTP
processing is done using the HTX internal representation. Since the version 2.0,
It is the default mode. So now, it is no more possible to disable the HTX to
fallback on the legacy HTTP mode. If you still use "[no] option http-use-htx", a
warning will be emitted during HAProxy startup. Note the passthough multiplexer
is now only usable for TCP proxies.
2019-07-19 09:18:27 +02:00
Olivier Houchard
2ab3dada01 BUG/MEDIUM: connections: Make sure we're unsubscribe before upgrading the mux.
Just calling conn_force_unsubscribe() from conn_upgrade_mux_fe() is not
enough, as there may be multiple XPRT involved. Instead, require that
any user of conn_upgrade_mux_fe() unsubscribe itself before calling it.
This should fix upgrading a TCP connection to HTX when using SSL.

This should be backported to 2.0.
2019-07-03 13:57:30 +02:00
Tim Duesterhus
24915a55da MEDIUM: Remove 'option independant-streams'
It is deprecated with HAProxy 1.5. Time to remove it.
2019-06-17 13:35:54 +02:00
Tim Duesterhus
86e6b6ebf8 MEDIUM: Make '(cli|con|srv)timeout' directive fatal
They were deprecated with HAProxy 1.5. Time to remove them.
2019-06-17 13:35:54 +02:00
Willy Tarreau
9faebe34cd MEDIUM: tools: improve time format error detection
As reported in GH issue #109 and in discourse issue
https://discourse.haproxy.org/t/haproxy-returns-408-or-504-error-when-timeout-client-value-is-every-25d
the time parser doesn't error on overflows nor underflows. This is a
recurring problem which additionally has the bad taste of taking a long
time before hitting the user.

This patch makes parse_time_err() return special error codes for overflows
and underflows, and adds the control in the call places to report suitable
errors depending on the requested unit. In practice, underflows are almost
never returned as the parsing function takes care of rounding values up,
so this might possibly happen on 64-bit overflows returning exactly zero
after rounding though. It is not really possible to cut the patch into
pieces as it changes the function's API, hence all callers.

Tests were run on about every relevant part (cookie maxlife/maxidle,
server inter, stats timeout, timeout*, cli's set timeout command,
tcp-request/response inspect-delay).
2019-06-07 19:32:02 +02:00
Willy Tarreau
7067b3a92e BUG/MINOR: deinit/threads: make hard-stop-after perform a clean exit
As reported in GH issue #99, when hard-stop-after triggers and threads
are in use, the chance that any thread releases the resources in use by
the other ones is non-null. Thus no thread should be allowed to deinit()
nor exit by itself.

Here we take a different approach. We simply use a 3rd possible value
for the "killed" variable so that all threads know they must break out
of the run-poll-loop and immediately stop.

This patch was tested by commenting the stream_shutdown() calls in
hard_stop() to increase the chances to see a stream use released
resources. With this fix applied, it never crashes anymore.

This fix should be backported to 1.9 and 1.8.
2019-06-02 11:30:07 +02:00
Willy Tarreau
e5733234f6 CLEANUP: build: rename some build macros to use the USE_* ones
We still have quite a number of build macros which are mapped 1:1 to a
USE_something setting in the makefile but which have a different name.
This patch cleans this up by renaming them to use the USE_something
one, allowing to clean up the makefile and make it more obvious when
reading the code what build option needs to be added.

The following renames were done :

 ENABLE_POLL -> USE_POLL
 ENABLE_EPOLL -> USE_EPOLL
 ENABLE_KQUEUE -> USE_KQUEUE
 ENABLE_EVPORTS -> USE_EVPORTS
 TPROXY -> USE_TPROXY
 NETFILTER -> USE_NETFILTER
 NEED_CRYPT_H -> USE_CRYPT_H
 CONFIG_HAP_CRYPT -> USE_LIBCRYPT
 CONFIG_HAP_NS -> DUSE_NS
 CONFIG_HAP_LINUX_SPLICE -> USE_LINUX_SPLICE
 CONFIG_HAP_LINUX_TPROXY -> USE_LINUX_TPROXY
 CONFIG_HAP_LINUX_VSYSCALL -> USE_LINUX_VSYSCALL
2019-05-22 19:47:57 +02:00
Olivier Houchard
ddf0e03585 MINOR: streams: Introduce a new retry-on keyword, all-retryable-errors.
Add a new retry-on keyword, "all-retryable-errors", that activates retry
for all errors that are considered retryable.
This currently activates retry for "conn-failure", "empty-response",
"junk-respones", "response-timeout", "0rtt-rejected", "500", "502", "503" and
"504".
2019-05-10 18:05:35 +02:00
Frédéric Lécaille
1b8e68e89a MEDIUM: stick-table: Stop handling stick-tables as proxies.
This patch adds the support for the "table" line parsing in "peers" sections
to declare stick-table in such sections. This also prevents the user from having
to declare dummy backends sections with a unique stick-table inside.
Even if still supported, this usage will become deprecated.

To do so, the ->table member of proxy struct which is a stktable struct is replaced
by a pointer to a stktable struct allocated at parsing time in src/cfgparse-listen.c
for the dummy stick-table backends and in src/cfgparse.c for "peers" sections.
This has an impact on the code for stick-table sample converters and on the stickiness
rules parsers which first store the name of the dummy before resolving the rules.
This patch replaces proxy_tbl_by_name() calls by stktable_find_by_name() calls
to lookup for stick-tables stored in "stktable_by_name" ebtree at parsing time.
There is only one remaining place where proxy_tbl_by_name() is used: src/hlua.c.

At several places in the code we relied on the fact that ->size member of stick-table
was equal to zero to consider the stick-table was present by not configured,
this do not make sense anymore as ->table member of struct proxyis fow now on a pointer.
These tests are replaced by a test on ->table value itself.

In "peers" section we do not have to temporary store the name of the section the
stick-table are attached to because this name is obviously already known just after
having entered this "peers" section.

About the CLI stick-table I/O handler, the pointer to proxy struct is replaced by
a pointer to a stktable struct.
2019-05-07 06:54:06 +02:00
Olivier Houchard
e3249a98e2 MEDIUM: streams: Add a new keyword for retry-on, "junk-response"
Add a way to retry requests if we got a junk response from the server, ie
an incomplete response, or something that is not valid HTTP.
To do so, one can use the new "junk-response" keyword for retry-on.
2019-05-04 10:20:24 +02:00
Olivier Houchard
865d8392bb MEDIUM: streams: Add a way to replay failed 0rtt requests.
Add a new keyword for retry-on, 0rtt-rejected. If set, we will try to
replay requests for which we sent early data that got rejected by the
server.
If that option is set, we will attempt to use 0rtt if "allow-0rtt" is set
on the server line even if the client didn't send early data.
2019-05-04 10:20:24 +02:00
Olivier Houchard
a254a37ad7 MEDIUM: streams: Add the ability to retry a request on L7 failure.
When running in HTX mode, if we sent the request, but failed to get the
answer, either because the server just closed its socket, we hit a server
timeout, or we get a 404, 408, 425, 500, 501, 502, 503 or 504 error,
attempt to retry the request, exactly as if we just failed to connect to
the server.

To do so, add a new backend keyword, "retry-on".

It accepts a list of keywords, which can be "none" (never retry),
"conn-failure" (we failed to connect, or to do the SSL handshake),
"empty-response" (the server closed the connection without answering),
"response-timeout" (we timed out while waiting for the server response),
or "404", "408", "425", "500", "501", "502", "503" and "504".

The default is "conn-failure".
2019-05-04 10:19:56 +02:00
Christopher Faulet
1d2b586cdd MAJOR: htx: Enable the HTX mode by default for all proxies
The legacy HTTP mode is no more the default one. So now, by default, without any
option in your configuration, all proxies will use the HTX mode. The line
"option http-use-htx" in proxy sections are now useless, except to cancel the
legacy HTTP mode. To fallback on legacy HTTP mode, you should use the line "no
option http-use-htx" explicitly.

Note that the reg-tests still work by default on legacy HTTP mode. The HTX will
be enabled by default in a futur commit.
2019-04-12 22:06:53 +02:00
Christopher Faulet
bbe685452f MAJOR: proxy/htx: Handle mux upgrades from TCP to HTTP in HTX mode
It is now possible to upgrade TCP streams to HTX when an HTTP backend is set for
a TCP frontend (both with the HTX enabled). So concretely, in such case, an
upgrade is performed from the mux pt to the mux h1. The current CS and the
channel's buffer are used to initialize the mux h1.
2019-04-12 22:06:53 +02:00
Christopher Faulet
eb7098035c MEDIUM: htx: Allow the option http-use-htx to be used on TCP proxies too
This will be mandatory to allow upgrades from TCP to HTTP in HTX. Of course, raw
buffers will still be used by default on TCP proxies, this option sets or
not. But if you want to handle mux upgrades from a TCP proxy, you must enable
the HTX on it and on all its backends.

There is only a small change in the lua code. Because TCP proxies can be HTX
aware, to exclude TCP services only for HTTP proxies, we must also check the
mode (TCP/HTTP) now.
2019-04-12 22:06:53 +02:00
Frédéric Lécaille
2365fb0c97 BUG/MAJOR: config: Wrong maxconn adjustment.
Before c8d5b95 the "maxconn" of the backend of dynamic "use_backend"
rules was not modified (this does not make sense and this is correct).
When implementing proxy_adjust_all_maxconn(), c8d5b95 commit missed this case.
With this patch we adjust the "maxconn" of the backend of such rules only if
they are not dynamic.

Without this patch reg-tests/http-rules/h00003.vtc could make haproxy crash.
2019-03-07 17:07:23 +01:00
Willy Tarreau
c8d5b95e6d MEDIUM: config: don't enforce a low frontend maxconn value anymore
Historically the default frontend's maxconn used to be quite low (2000),
which was sufficient two decades ago but often proved to be a problem
when users had purposely set the global maxconn value but forgot to set
the frontend's.

There is no point in keeping this arbitrary limit for frontends : when
the global maxconn is lower, it's already too high and when the global
maxconn is much higher, it becomes a limiting factor which causes trouble
in production.

This commit allows the value to be set to zero, which becomes the new
default value, to mean it's not directly limited, or in fact it's set
to the global maxconn. Since this operation used to be performed before
computing a possibly automatic global maxconn based on memory limits,
the calculation of the maxconn value and its propagation to the backends'
fullconn has now moved to a dedicated function, proxy_adjust_all_maxconn(),
which is called once the global maxconn is stabilized.

This comes with two benefits :
  1) a configuration missing "maxconn" in the defaults section will not
     limit itself to a magically hardcoded value but will scale up to the
     global maxconn ;

  2) when the global maxconn is not set and memory limits are used instead,
     the frontends' maxconn automatically adapts, and the backends' fullconn
     as well.
2019-02-28 17:05:32 +01:00
Willy Tarreau
d89cc8bfc0 MINOR: proxy: do not change the listeners' maxconn when updating the frontend's
It is possible to update a frontend's maxconn from the CLI. Unfortunately
when doing this it scratches all listeners' maxconn values and sets them
all to the new frontend's value. This can be problematic when mixing
different traffic classes (bind to interface or private networks, etc).

Now that the listener's maxconn is allowed to remain unset, let's not
change these values when setting the frontend's maxconn. This way the
overall frontend's limit can be raised but if certain specific listeners
had their own value forced in the config, they will be preserved. This
makes more sense and is more in line with the principle of defaults
propagation.
2019-02-28 17:05:32 +01:00
Willy Tarreau
a8cf66bcab MINOR: listener: do not needlessly set l->maxconn
It's pointless to always set and maintain l->maxconn because the accept
loop already enforces the frontend's limit anyway. Thus let's stop setting
this value by default and keep it to zero meaning "no limit". This way the
frontend's maxconn will be used by default. Of course if a value is set,
it will be enforced.
2019-02-28 17:05:32 +01:00
Willy Tarreau
6daac19b3f MINOR: config: simplify bind_proc processing using proc_mask()
At a number of places we used to have null tests on bind_proc for
listeners and proxies. Let's simplify all these tests by always
having the proper bits reported via proc_mask().
2019-02-04 05:09:16 +01:00
Willy Tarreau
3e451842dc BUG/MEDIUM: htx: check the HTX compatibility in dynamic use-backend rules
I would have sworn it was done, probably we lost it during the refactoring.
If a frontend is in HTX and the backend not (and conersely), this is
normally detected at config parsing time unless the rule is dynamic. In
this case we must abort with an error 500. The logs will report "RR"
(resource issue while processing request) with the frontend and the
backend assigned, so that it's possible to figure what was attempted.

This must be backported to 1.9.
2019-02-01 15:09:54 +01:00
Willy Tarreau
0108d90c6c MEDIUM: init: convert all trivial registration calls to initcalls
This switches explicit calls to various trivial registration methods for
keywords, muxes or protocols from constructors to INITCALL1 at stage
STG_REGISTER. All these calls have in common to consume a single pointer
and return void. Doing this removes 26 constructors. The following calls
were addressed :

- acl_register_keywords
- bind_register_keywords
- cfg_register_keywords
- cli_register_kw
- flt_register_keywords
- http_req_keywords_register
- http_res_keywords_register
- protocol_register
- register_mux_proto
- sample_register_convs
- sample_register_fetches
- srv_register_keywords
- tcp_req_conn_keywords_register
- tcp_req_cont_keywords_register
- tcp_req_sess_keywords_register
- tcp_res_cont_keywords_register
- flt_register_keywords
2018-11-26 19:50:32 +01:00
Willy Tarreau
3a1f5fda10 REORG: config: extract the proxy parser into cfgparse-listen.c
This was the largest function of the whole file, taking a rough second
to build alone. Let's move it to a distinct file along with a few
dependencies. Doing so saved about 2 seconds on the total build time.
2018-11-19 06:47:09 +01:00
Joseph Herlant
9edebb8568 MINOR: Fix typos in error messages in the proxy subsystem
Fix typos in error messages that will be user-visible in the proxy
subsystem.
2018-11-18 22:23:15 +01:00
Joseph Herlant
59dd295926 CLEANUP: fix typos in the proxy subsystem
Fix typos in the code comments of the proxy subsystem.
2018-11-18 22:23:15 +01:00
Willy Tarreau
db398435aa MINOR: stream-int: replace si_cant_put() with si_rx_room_{blk,rdy}()
Remaining calls to si_cant_put() were all for lack of room and were
turned to si_rx_room_blk(). A few places where SI_FL_RXBLK_ROOM was
cleared by hand were converted to si_rx_room_rdy().

The now unused si_cant_put() function was removed.
2018-11-18 21:41:50 +01:00
William Lallemand
c59f9884d7 MEDIUM: listeners: support unstoppable listener
An unstoppable listener is a listener which won't be stop during a soft
stop. The unstoppable_jobs variable is incremented and the listener
won't prevent the process to leave properly.

It is not a good idea to use this feature (the LI_O_NOSTOP flag) with a
listener that need to be bind again on another process during a soft
reload.
2018-11-16 17:05:40 +01:00
Willy Tarreau
0cd3bd628a MINOR: stream-int: rename si_applet_{want|stop|cant}_{get|put}
It doesn't make sense to limit this code to applets, as any stream
interface can use it. Let's rename it by simply dropping the "applet_"
part of the name. No other change was made except updating the comments.
2018-11-11 10:18:37 +01:00
William Lallemand
cf62f7e3cb MEDIUM: cli: implement 'mode cli' proxy analyzers
This patch implements analysers for parsing the CLI and extra features
for the master's CLI.

For each command (sent alone, or separated by ; or \n) the request
analyser will determine to which server it should send the request.

The 'mode cli' proxy is able to parse a prefix for each command which is
used to select the apropriate server. The prefix start by @ and is
followed by "master", the PID preceded by ! or the relative PID. (e.g.
@master, @1, @!1234). The servers are not round-robined anymore.

The command is sent with a SHUTW which force the server to close the
connection after sending its response. However the proxy allows a
keepalive connection on the client side and does not close.

The response analyser does not do much stuff, it only reinits the
connection when it received a close from the server, and forward the
response. It does not analyze the response data.
The only guarantee of the end of the response is the close of the
server, we can't rely on the double \n since it's not send by every
command.

This could be reimplemented later as a filter.
2018-10-28 14:03:06 +01:00
Willy Tarreau
4bc7d90d3b MEDIUM: snapshot: merge the captured data after the descriptor
Instead of having a separate area for the captured data, we now have a
contigous block made of the descriptor and the data. At the moment, since
the area is dynamically allocated, we can adjust its size to what is
needed, but the idea is to quickly switch to a pool and an LRU list.
2018-09-07 20:07:17 +02:00
Willy Tarreau
c55015ee5b MEDIUM: snapshots: dynamically allocate the snapshots
Now upon error we dynamically allocate the snapshot instead of overwriting
it. This way there is no more memory wasted in the proxy to hold the two
error snapshot descriptors. Also an appreciable side effect of this is that
the proxy's lock is only taken during the pointer swap, no more while copying
the buffer's contents. This saves 480 bytes of memory per proxy.
2018-09-07 19:59:58 +02:00
Willy Tarreau
36b2736a69 BUG/MEDIUM: snapshot: take the proxy's lock while dumping errors
The proxy's lock it held while filling the error but not while dumping
it, so it's possible to dereference pointers being replaced, typically
server pointers. The risk is very low and unlikely but not inexistent.

Since "show errors" is rarely used in parallel, let's simply grab the
proxy's lock while dumping. Ideally we should use an R/W lock here but
it will not make any difference.

This patch must be backported to 1.8, but the code is in proto_http.c
there, though mostly similar.
2018-09-07 19:55:44 +02:00
Willy Tarreau
ddb68ac69e REORG: cli: move the "show errors" handler from http to proxy
There's nothing HTTP-specific there anymore at all, let's move this
to the proxy where it belongs.
2018-09-07 18:36:50 +02:00
Willy Tarreau
75fb65a51f MINOR: proxy: add a new generic proxy_capture_error()
This function now captures an error regardless of its side and protocol.
The caller must pass a number of elements and may pass a protocol-specific
structure and a callback to display it. Later this function may deal with
more advanced allocation techniques to avoid allocating as many buffers
as proxies.
2018-09-07 18:36:04 +02:00
Baptiste Assmann
6d0f38f00d BUG/MEDIUM: dns/server: fix incomatibility between SRV resolution and server state file
Server state file has no indication that a server is currently managed
by a DNS SRV resolution.
And thus, both feature (DNS SRV resolution and server state), when used
together, does not provide the expected behavior: a smooth experience...

This patch introduce the "SRV record name" in the server state file and
loads and applies it if found and wherever required.

This patch applies to haproxy-dev branch only. For backport, a specific patch
is provided for 1.8.
2018-09-04 17:40:22 +02:00
Willy Tarreau
a275a3710e BUG/MEDIUM: cli/threads: protect all "proxy" commands against concurrent updates
The proxy-related commands like "{enable|disable|shutdown} frontend",
"{enable|disable} dynamic-cookie", "set dynamic-cookie-key" were not
protected against concurrent accesses making their use dangerous with
threads.

This patch must be backported to 1.8.
2018-08-21 14:58:25 +02:00
Patrick Hemmer
0355dabd7c MINOR: queue: replace the linked list with a tree
We'll need trees to manage the queues by priorities. This change replaces
the list with a tree based on a single key. It's effectively a list but
allows us to get rid of the list management right now.
2018-08-10 15:06:27 +02:00
Willy Tarreau
83061a820e MAJOR: chunks: replace struct chunk with struct buffer
Now all the code used to manipulate chunks uses a struct buffer instead.
The functions are still called "chunk*", and some of them will progressively
move to the generic buffer handling code as they are cleaned up.
2018-07-19 16:23:43 +02:00
Olivier Houchard
9f6af33222 MINOR: tasks: Change the task API so that the callback takes 3 arguments.
In preparation for thread-specific runqueues, change the task API so that
the callback takes 3 arguments, the task itself, the context, and the state,
those were retrieved from the task before. This will allow these elements to
change atomically in the scheduler while the application uses the copied
value, and even to have NULL tasks later.
2018-05-26 19:23:57 +02:00
Daniel Corbett
9215ffa6b2 BUG/MEDIUM: servers: Add srv_addr default placeholder to the state file
When creating a state file using "show servers state" an empty field is
created in the srv_addr column if the server is from the socket family
AF_UNIX.  This leads to a warning on start up when using
"load-server-state-from-file". This patch defaults srv_addr to "-" if
the socket family is not covered.

This patch should be backported to 1.8.
2018-05-24 22:06:08 +02:00
Aurélien Nephtali
abbf607105 MEDIUM: cli: Add payload support
In order to use arbitrary data in the CLI (multiple lines or group of words
that must be considered as a whole, for example), it is now possible to add a
payload to the commands. To do so, the first line needs to end with a special
pattern: <<\n. Everything that follows will be left untouched by the CLI parser
and will be passed to the commands parsers.

Per-command support will need to be added to take advantage of this
feature.

Signed-off-by: Aurélien Nephtali <aurelien.nephtali@corp.ovh.com>
2018-04-26 14:19:33 +02:00
Willy Tarreau
bafbe01028 CLEANUP: pools: rename all pool functions and pointers to remove this "2"
During the migration to the second version of the pools, the new
functions and pool pointers were all called "pool_something2()" and
"pool2_something". Now there's no more pool v1 code and it's a real
pain to still have to deal with this. Let's clean this up now by
removing the "2" everywhere, and by renaming the pool heads
"pool_head_something".
2017-11-24 17:49:53 +01:00
Olivier Houchard
fbc74e8556 MINOR/CLEANUP: proxy: rename "proxy" to "proxies_list"
Rename the global variable "proxy" to "proxies_list".
There's been multiple proxies in haproxy for quite some time, and "proxy"
is a potential source of bugs, a number of functions have a "proxy" argument,
and some code used "proxy" when it really meant "px" or "curproxy". It worked
by pure luck, because it usually happened while parsing the config, and thus
"proxy" pointed to the currently parsed proxy, but we should probably not
rely on this.

[wt: some of these are definitely fixes that are worth backporting]
2017-11-24 17:21:27 +01:00