Merge branch 'devel'

2 files changed, 2162 insertions, 319 deletions

diff --git a/tcl8.6/library/http/http.tcl b/tcl8.6/library/http/http.tcl
index 9f5310b..f82bced 100644
--- a/tcl8.6/library/http/http.tcl
+++ b/tcl8.6/library/http/http.tcl
@@ -11,7 +11,7 @@
 package require Tcl 8.6-
 # Keep this in sync with pkgIndex.tcl and with the install directories in
 # Makefiles
-package provide http 2.8.12
+package provide http 2.9.0
 
 namespace eval http {
     # Allow resourcing to not clobber existing data
@@ -20,26 +20,30 @@ namespace eval http {
     if {![info exists http]} {
 	array set http {
 	    -accept */*
+	    -pipeline 1
+	    -postfresh 0
 	    -proxyhost {}
 	    -proxyport {}
 	    -proxyfilter http::ProxyRequired
+	    -repost 0
 	    -urlencoding utf-8
+	    -zip 1
 	}
-	# We need a useragent string of this style or various servers will refuse to
-	# send us compressed content even when we ask for it. This follows the
-	# de-facto layout of user-agent strings in current browsers.
+	# We need a useragent string of this style or various servers will
+	# refuse to send us compressed content even when we ask for it. This
+	# follows the de-facto layout of user-agent strings in current browsers.
 	# Safe interpreters do not have ::tcl_platform(os) or
 	# ::tcl_platform(osVersion).
 	if {[interp issafe]} {
 	    set http(-useragent) "Mozilla/5.0\
-                (Windows; U;\
-                Windows NT 10.0)\
-                http/[package provide http] Tcl/[package provide Tcl]"
+		(Windows; U;\
+		Windows NT 10.0)\
+		http/[package provide http] Tcl/[package provide Tcl]"
 	} else {
 	    set http(-useragent) "Mozilla/5.0\
-                ([string totitle $::tcl_platform(platform)]; U;\
-                $::tcl_platform(os) $::tcl_platform(osVersion))\
-                http/[package provide http] Tcl/[package provide Tcl]"
+		([string totitle $::tcl_platform(platform)]; U;\
+		$::tcl_platform(os) $::tcl_platform(osVersion))\
+		http/[package provide http] Tcl/[package provide Tcl]"
 	}
     }
 
@@ -60,14 +64,42 @@ namespace eval http {
 	variable formMap [array get map]
 
 	# Create a map for HTTP/1.1 open sockets
-	variable socketmap
-	if {[info exists socketmap]} {
-	    # Close but don't remove open sockets on re-init
-	    foreach {url sock} [array get socketmap] {
-		catch {close $sock}
+	variable socketMapping
+	variable socketRdState
+	variable socketWrState
+	variable socketRdQueue
+	variable socketWrQueue
+	variable socketClosing
+	variable socketPlayCmd
+	if {[info exists socketMapping]} {
+	    # Close open sockets on re-init.  Do not permit retries.
+	    foreach {url sock} [array get socketMapping] {
+		unset -nocomplain socketClosing($url)
+		unset -nocomplain socketPlayCmd($url)
+		CloseSocket $sock
 	    }
 	}
-	array set socketmap {}
+
+	# CloseSocket should have unset the socket* arrays, one element at
+	# a time.  Now unset anything that was overlooked.
+	# Traces on "unset socketRdState(*)" will call CancelReadPipeline and
+	# cancel any queued responses.
+	# Traces on "unset socketWrState(*)" will call CancelWritePipeline and
+	# cancel any queued requests.
+	array unset socketMapping
+	array unset socketRdState
+	array unset socketWrState
+	array unset socketRdQueue
+	array unset socketWrQueue
+	array unset socketClosing
+	array unset socketPlayCmd
+	array set socketMapping {}
+	array set socketRdState {}
+	array set socketWrState {}
+	array set socketRdQueue {}
+	array set socketWrQueue {}
+	array set socketClosing {}
+	array set socketPlayCmd {}
     }
     init
 
@@ -95,8 +127,13 @@ namespace eval http {
 	set defaultKeepalive 0
     }
 
-    namespace export geturl config reset wait formatQuery register unregister
-    # Useful, but not exported: data size status code
+    namespace export geturl config reset wait formatQuery quoteString
+    namespace export register unregister registerError
+    # - Useful, but not exported: data, size, status, code, cleanup, error,
+    #   meta, ncode, mapReply, init.  Comments suggest that "init" can be used
+    #   for re-initialisation, although the command is undocumented.
+    # - Not exported, probably should be upper-case initial letter as part
+    #   of the internals: getTextLine, make-transformation-chunked.
 }
 
 # http::Log --
@@ -190,40 +227,279 @@ proc http::config {args} {
 # Arguments:
 #	token	    Connection token.
 #	errormsg    (optional) If set, forces status to error.
-#       skipCB      (optional) If set, don't call the -command callback. This
+#	skipCB      (optional) If set, don't call the -command callback. This
 #		    is useful when geturl wants to throw an exception instead
 #		    of calling the callback. That way, the same error isn't
 #		    reported to two places.
 #
 # Side Effects:
-#        Closes the socket
+#        May close the socket.
 
 proc http::Finish {token {errormsg ""} {skipCB 0}} {
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
     variable $token
     upvar 0 $token state
     global errorInfo errorCode
+    set closeQueue 0
     if {$errormsg ne ""} {
 	set state(error) [list $errormsg $errorInfo $errorCode]
 	set state(status) "error"
     }
-    if { ($state(status) eq "timeout")
+    if {[info commands ${token}EventCoroutine] ne {}} {
+	rename ${token}EventCoroutine {}
+    }
+    if {  ($state(status) eq "timeout")
        || ($state(status) eq "error")
+       || ($state(status) eq "eof")
        || ([info exists state(-keepalive)] && !$state(-keepalive))
        || ([info exists state(connection)] && ($state(connection) eq "close"))
     } {
-        CloseSocket $state(sock) $token
+	set closeQueue 1
+	set connId $state(socketinfo)
+	set sock $state(sock)
+	CloseSocket $state(sock) $token
+    } elseif {
+	  ([info exists state(-keepalive)] && $state(-keepalive))
+       && ([info exists state(connection)] && ($state(connection) ne "close"))
+    } {
+	KeepSocket $token
     }
     if {[info exists state(after)]} {
 	after cancel $state(after)
+	unset state(after)
     }
-    if {[info exists state(-command)] && !$skipCB
-	    && ![info exists state(done-command-cb)]} {
+    if {[info exists state(-command)] && (!$skipCB)
+	    && (![info exists state(done-command-cb)])} {
 	set state(done-command-cb) yes
 	if {[catch {eval $state(-command) {$token}} err] && $errormsg eq ""} {
 	    set state(error) [list $err $errorInfo $errorCode]
 	    set state(status) error
 	}
     }
+
+    if {    $closeQueue
+	 && [info exists socketMapping($connId)]
+	 && ($socketMapping($connId) eq $sock)
+    } {
+	http::CloseQueuedQueries $connId $token
+    }
+}
+
+# http::KeepSocket -
+#
+#	Keep a socket in the persistent sockets table and connect it to its next
+#	queued task if possible.  Otherwise leave it idle and ready for its next
+#	use.
+#
+#	If $socketClosing(*), then ($state(connection) eq "close") and therefore
+#	this command will not be called by Finish.
+#
+# Arguments:
+#	token	    Connection token.
+
+proc http::KeepSocket {token} {
+    variable http
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
+    variable $token
+    upvar 0 $token state
+    set tk [namespace tail $token]
+
+    # Keep this socket open for another request ("Keep-Alive").
+    # React if the server half-closes the socket.
+    # Discussion is in http::geturl.
+    catch {fileevent $state(sock) readable [list http::CheckEof $state(sock)]}
+
+    # The line below should not be changed in production code.
+    # It is edited by the test suite.
+    set TEST_EOF 0
+    if {$TEST_EOF} {
+	# ONLY for testing reaction to server eof.
+	# No server timeouts will be caught.
+	catch {fileevent $state(sock) readable {}}
+    }
+
+    if {    [info exists state(socketinfo)]
+	 && [info exists socketMapping($state(socketinfo))]
+    } {
+	set connId $state(socketinfo)
+	# The value "Rready" is set only here.
+	set socketRdState($connId) Rready
+
+	if {    $state(-pipeline)
+	     && [info exists socketRdQueue($connId)]
+	     && [llength $socketRdQueue($connId)]
+	} {
+	    # The usual case for pipelined responses - if another response is
+	    # queued, arrange to read it.
+	    set token3 [lindex $socketRdQueue($connId) 0]
+	    set socketRdQueue($connId) [lrange $socketRdQueue($connId) 1 end]
+	    variable $token3
+	    upvar 0 $token3 state3
+	    set tk2 [namespace tail $token3]
+
+	    #Log pipelined, GRANT read access to $token3 in KeepSocket
+	    set socketRdState($connId) $token3
+	    ReceiveResponse $token3
+
+	    # Other pipelined cases.
+	    # - The test above ensures that, for the pipelined cases in the two
+	    #   tests below, the read queue is empty.
+	    # - In those two tests, check whether the next write will be
+	    #   nonpipeline.
+	} elseif {
+		$state(-pipeline)
+	     && [info exists socketWrState($connId)]
+	     && ($socketWrState($connId) eq "peNding")
+
+	     && [info exists socketWrQueue($connId)]
+	     && [llength $socketWrQueue($connId)]
+	     && (![set token3 [lindex $socketWrQueue($connId) 0]
+		   set ${token3}(-pipeline)
+		  ]
+		)
+	} {
+	    # This case:
+	    # - Now it the time to run the "pending" request.
+	    # - The next token in the write queue is nonpipeline, and
+	    #   socketWrState has been marked "pending" (in
+	    #   http::NextPipelinedWrite or http::geturl) so a new pipelined
+	    #   request cannot jump the queue.
+	    #
+	    # Tests:
+	    # - In this case the read queue (tested above) is empty and this
+	    #   "pending" write token is in front of the rest of the write
+	    #   queue.
+	    # - The write state is not Wready and therefore appears to be busy,
+	    #   but because it is "pending" we know that it is reserved for the
+	    #   first item in the write queue, a non-pipelined request that is
+	    #   waiting for the read queue to empty.  That has now happened: so
+	    #   give that request read and write access.
+	    variable $token3
+	    set conn [set ${token3}(tmpConnArgs)]
+	    #Log nonpipeline, GRANT r/w access to $token3 in KeepSocket
+	    set socketRdState($connId) $token3
+	    set socketWrState($connId) $token3
+	    set socketWrQueue($connId) [lrange $socketWrQueue($connId) 1 end]
+	    # Connect does its own fconfigure.
+	    fileevent $state(sock) writable [list http::Connect $token3 {*}$conn]
+	    #Log ---- $state(sock) << conn to $token3 for HTTP request (c)
+
+	} elseif {
+		$state(-pipeline)
+	     && [info exists socketWrState($connId)]
+	     && ($socketWrState($connId) eq "peNding")
+
+	} {
+	    # Should not come here.  The second block in the previous "elseif"
+	    # test should be tautologous (but was needed in an earlier
+	    # implementation) and will be removed after testing.
+	    # If we get here, the value "pending" was assigned in error.
+	    # This error would block the queue for ever.
+	    Log ^X$tk <<<<< Error in queueing of requests >>>>> - token $token
+
+	} elseif {
+		$state(-pipeline)
+	     && [info exists socketWrState($connId)]
+	     && ($socketWrState($connId) eq "Wready")
+
+	     && [info exists socketWrQueue($connId)]
+	     && [llength $socketWrQueue($connId)]
+	     && (![set token3 [lindex $socketWrQueue($connId) 0]
+		   set ${token3}(-pipeline)
+		  ]
+		)
+	} {
+	    # This case:
+	    # - The next token in the write queue is nonpipeline, and
+	    #   socketWrState is Wready.  Get the next event from socketWrQueue.
+	    # Tests:
+	    # - In this case the read state (tested above) is Rready and the
+	    #   write state (tested here) is Wready - there is no "pending"
+	    #   request.
+	    # Code:
+	    # - The code is the same as the code below for the nonpipelined
+	    #   case with a queued request.
+	    variable $token3
+	    set conn [set ${token3}(tmpConnArgs)]
+	    #Log nonpipeline, GRANT r/w access to $token3 in KeepSocket
+	    set socketRdState($connId) $token3
+	    set socketWrState($connId) $token3
+	    set socketWrQueue($connId) [lrange $socketWrQueue($connId) 1 end]
+	    # Connect does its own fconfigure.
+	    fileevent $state(sock) writable [list http::Connect $token3 {*}$conn]
+	    #Log ---- $state(sock) << conn to $token3 for HTTP request (c)
+
+	} elseif {
+		(!$state(-pipeline))
+	     && [info exists socketWrQueue($connId)]
+	     && [llength $socketWrQueue($connId)]
+	     && ($state(connection) ne "close")
+	} {
+	    # If not pipelined, (socketRdState eq Rready) tells us that we are
+	    # ready for the next write - there is no need to check
+	    # socketWrState. Write the next request, if one is waiting.
+	    # If the next request is pipelined, it receives premature read
+	    # access to the socket. This is not a problem.
+	    set token3 [lindex $socketWrQueue($connId) 0]
+	    variable $token3
+	    set conn [set ${token3}(tmpConnArgs)]
+	    #Log nonpipeline, GRANT r/w access to $token3 in KeepSocket
+	    set socketRdState($connId) $token3
+	    set socketWrState($connId) $token3
+	    set socketWrQueue($connId) [lrange $socketWrQueue($connId) 1 end]
+	    # Connect does its own fconfigure.
+	    fileevent $state(sock) writable [list http::Connect $token3 {*}$conn]
+	    #Log ---- $state(sock) << conn to $token3 for HTTP request (d)
+
+	} elseif {(!$state(-pipeline))} {
+	    set socketWrState($connId) Wready
+	    # Rready and Wready and idle: nothing to do.
+	}
+
+    } else {
+	CloseSocket $state(sock) $token
+	# There is no socketMapping($state(socketinfo)), so it does not matter
+	# that CloseQueuedQueries is not called.
+    }
+}
+
+# http::CheckEof -
+#
+#	Read from a socket and close it if eof.
+#	The command is bound to "fileevent readable" on an idle socket, and
+#	"eof" is the only event that should trigger the binding, occurring when
+#	the server times out and half-closes the socket.
+#
+#	A read is necessary so that [eof] gives a meaningful result.
+#	Any bytes sent are junk (or a bug).
+
+proc http::CheckEof {sock} {
+    set junk [read $sock]
+    set n [string length $junk]
+    if {$n} {
+	Log "WARNING: $n bytes received but no HTTP request sent"
+    }
+
+    if {[catch {eof $sock} res] || $res} {
+	# The server has half-closed the socket.
+	# If a new write has started, its transaction will fail and
+	# will then be error-handled.
+	CloseSocket $sock
+    }
 }
 
 # http::CloseSocket -
@@ -231,44 +507,137 @@ proc http::Finish {token {errormsg ""} {skipCB 0}} {
 #	Close a socket and remove it from the persistent sockets table.  If
 #	possible an http token is included here but when we are called from a
 #	fileevent on remote closure we need to find the correct entry - hence
-#	the second section.
+#	the "else" block of the first "if" command.
+
+proc http::CloseSocket {s {token {}}} {
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
+    set tk [namespace tail $token]
 
-proc ::http::CloseSocket {s {token {}}} {
-    variable socketmap
     catch {fileevent $s readable {}}
-    set conn_id {}
+    set connId {}
     if {$token ne ""} {
-        variable $token
-        upvar 0 $token state
-        if {[info exists state(socketinfo)]} {
-	    set conn_id $state(socketinfo)
-        }
+	variable $token
+	upvar 0 $token state
+	if {[info exists state(socketinfo)]} {
+	    set connId $state(socketinfo)
+	}
     } else {
-        set map [array get socketmap]
-        set ndx [lsearch -exact $map $s]
-        if {$ndx != -1} {
+	set map [array get socketMapping]
+	set ndx [lsearch -exact $map $s]
+	if {$ndx != -1} {
 	    incr ndx -1
-	    set conn_id [lindex $map $ndx]
-        }
+	    set connId [lindex $map $ndx]
+	}
     }
-    if {$conn_id eq {} || ![info exists socketmap($conn_id)]} {
-        Log "Closing socket $s (no connection info)"
-        if {[catch {close $s} err]} {
-	    Log "Error: $err"
+    if {    ($connId ne {})
+	 && [info exists socketMapping($connId)]
+	 && ($socketMapping($connId) eq $s)
+    } {
+	Log "Closing connection $connId (sock $socketMapping($connId))"
+	if {[catch {close $socketMapping($connId)} err]} {
+	    Log "Error closing connection: $err"
+	}
+	if {$token eq {}} {
+	    # Cases with a non-empty token are handled by Finish, so the tokens
+	    # are finished in connection order.
+	    http::CloseQueuedQueries $connId
 	}
     } else {
-	if {[info exists socketmap($conn_id)]} {
-	    Log "Closing connection $conn_id (sock $socketmap($conn_id))"
-	    if {[catch {close $socketmap($conn_id)} err]} {
-		Log "Error: $err"
-	    }
-	    unset socketmap($conn_id)
-	} else {
-	    Log "Cannot close connection $conn_id - no socket in socket map"
+	Log "Closing socket $s (no connection info)"
+	if {[catch {close $s} err]} {
+	    Log "Error closing socket: $err"
 	}
     }
 }
 
+# http::CloseQueuedQueries
+#
+#	connId  - identifier "domain:port" for the connection
+#	token   - (optional) used only for logging
+#
+# Called from http::CloseSocket and http::Finish, after a connection is closed,
+# to clear the read and write queues if this has not already been done.
+
+proc http::CloseQueuedQueries {connId {token {}}} {
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
+    if {![info exists socketMapping($connId)]} {
+	# Command has already been called.
+	# Don't come here again - especially recursively.
+	return
+    }
+
+    # Used only for logging.
+    if {$token eq {}} {
+	set tk {}
+    } else {
+	set tk [namespace tail $token]
+    }
+
+    if {    [info exists socketPlayCmd($connId)]
+	 && ($socketPlayCmd($connId) ne {ReplayIfClose Wready {} {}})
+    } {
+	# Before unsetting, there is some unfinished business.
+	# - If the server sent "Connection: close", we have stored the command
+	#   for retrying any queued requests in socketPlayCmd, so copy that
+	#   value for execution below.  socketClosing(*) was also set.
+	# - Also clear the queues to prevent calls to Finish that would set the
+	#   state for the requests that will be retried to "finished with error
+	#   status".
+	set unfinished $socketPlayCmd($connId)
+	set socketRdQueue($connId) {}
+	set socketWrQueue($connId) {}
+    } else {
+	set unfinished {}
+    }
+
+    Unset $connId
+
+    if {$unfinished ne {}} {
+	Log ^R$tk Any unfinished transactions (excluding $token) failed \
+		- token $token
+	{*}$unfinished
+    }
+}
+
+# http::Unset
+#
+#	The trace on "unset socketRdState(*)" will call CancelReadPipeline
+#	and cancel any queued responses.
+#	The trace on "unset socketWrState(*)" will call CancelWritePipeline
+#	and cancel any queued requests.
+
+proc http::Unset {connId} {
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
+    unset socketMapping($connId)
+    unset socketRdState($connId)
+    unset socketWrState($connId)
+    unset -nocomplain socketRdQueue($connId)
+    unset -nocomplain socketWrQueue($connId)
+    unset -nocomplain socketClosing($connId)
+    unset -nocomplain socketPlayCmd($connId)
+}
+
 # http::reset --
 #
 #	See documentation for details.
@@ -278,7 +647,7 @@ proc ::http::CloseSocket {s {token {}}} {
 #	why	Status info.
 #
 # Side Effects:
-#       See Finish
+#        See Finish
 
 proc http::reset {token {why reset}} {
     variable $token
@@ -299,8 +668,8 @@ proc http::reset {token {why reset}} {
 #	Establishes a connection to a remote url via http.
 #
 # Arguments:
-#       url		The http URL to goget.
-#       args		Option value pairs. Valid options include:
+#	url		The http URL to goget.
+#	args		Option value pairs. Valid options include:
 #				-blocksize, -validate, -headers, -timeout
 # Results:
 #	Returns a token for this connection. This token is the name of an
@@ -320,9 +689,12 @@ proc http::geturl {url args} {
 	set http(uid) 0
     }
     set token [namespace current]::[incr http(uid)]
+    ##Log Starting http::geturl - token $token
     variable $token
     upvar 0 $token state
+    set tk [namespace tail $token]
     reset $token
+    Log ^A$tk URL $url - token $token
 
     # Process command options.
 
@@ -337,8 +709,9 @@ proc http::geturl {url args} {
 	-queryprogress	{}
 	-protocol	1.1
 	binary		0
-	state		connecting
+	state		created
 	meta		{}
+	method		{}
 	coding		{}
 	currentsize	0
 	totalsize	0
@@ -555,14 +928,7 @@ proc http::geturl {url args} {
     # Don't append the fragment!
     set state(url) $url
 
-    # If a timeout is specified we set up the after event and arrange for an
-    # asynchronous socket connection.
-
     set sockopts [list -async]
-    if {$state(-timeout) > 0} {
-	set state(after) [after $state(-timeout) \
-		[list http::reset $token timeout]]
-    }
 
     # If we are using the proxy, we must pass in the full URL that includes
     # the server name.
@@ -580,51 +946,295 @@ proc http::geturl {url args} {
     # c11a51c482]
     set state(accept-types) $http(-accept)
 
+    if {$isQuery || $isQueryChannel} {
+	# It's a POST.
+	# A client wishing to send a non-idempotent request SHOULD wait to send
+	# that request until it has received the response status for the
+	# previous request.
+	if {$http(-postfresh)} {
+	    # Override -keepalive for a POST.  Use a new connection, and thus
+	    # avoid the small risk of a race against server timeout.
+	    set state(-keepalive) 0
+	} else {
+	    # Allow -keepalive but do not -pipeline - wait for the previous
+	    # transaction to finish.
+	    # There is a small risk of a race against server timeout.
+	    set state(-pipeline) 0
+	}
+    } else {
+	# It's a GET or HEAD.
+	set state(-pipeline) $http(-pipeline)
+    }
+
     # See if we are supposed to use a previously opened channel.
+    # - In principle, ANY call to http::geturl could use a previously opened
+    #   channel if it is available - the "Connection: keep-alive" header is a
+    #   request to leave the channel open AFTER completion of this call.
+    # - In fact, we try to use an existing channel only if -keepalive 1 -- this
+    #   means that at most one channel is left open for each value of
+    #   $state(socketinfo). This property simplifies the mapping of open
+    #   channels.
+    set reusing 0
+    set alreadyQueued 0
     if {$state(-keepalive)} {
-	variable socketmap
-	if {[info exists socketmap($state(socketinfo))]} {
-	    if {[catch {fconfigure $socketmap($state(socketinfo))}]} {
-		Log "WARNING: socket for $state(socketinfo) was closed"
-		unset socketmap($state(socketinfo))
+	variable socketMapping
+	variable socketRdState
+	variable socketWrState
+	variable socketRdQueue
+	variable socketWrQueue
+	variable socketClosing
+	variable socketPlayCmd
+
+	if {[info exists socketMapping($state(socketinfo))]} {
+	    # - If the connection is idle, it has a "fileevent readable" binding
+	    #   to http::CheckEof, in case the server times out and half-closes
+	    #   the socket (http::CheckEof closes the other half).
+	    # - We leave this binding in place until just before the last
+	    #   puts+flush in http::Connected (GET/HEAD) or http::Write (POST),
+	    #   after which the HTTP response might be generated.
+
+	    if {    [info exists socketClosing($state(socketinfo))]
+		       && $socketClosing($state(socketinfo))
+	    } {
+		# socketClosing(*) is set because the server has sent a
+		# "Connection: close" header.
+		# Do not use the persistent socket again.
+		# Since we have only one persistent socket per server, and the
+		# old socket is not yet dead, add the request to the write queue
+		# of the dying socket, which will be replayed by ReplayIfClose.
+		# Also add it to socketWrQueue(*) which is used only if an error
+		# causes a call to Finish.
+		set reusing 1
+		set sock $socketMapping($state(socketinfo))
+		Log "reusing socket $sock for $state(socketinfo) - token $token"
+
+		set alreadyQueued 1
+		lassign $socketPlayCmd($state(socketinfo)) com0 com1 com2 com3
+		lappend com3 $token
+		set socketPlayCmd($state(socketinfo)) [list $com0 $com1 $com2 $com3]
+		lappend socketWrQueue($state(socketinfo)) $token
+	    } elseif {[catch {fconfigure $socketMapping($state(socketinfo))}]} {
+		# FIXME Is it still possible for this code to be executed? If
+		#       so, this could be another place to call TestForReplay,
+		#       rather than discarding the queued transactions.
+		Log "WARNING: socket for $state(socketinfo) was closed\
+			- token $token"
+		Log "WARNING - if testing, pay special attention to this\
+			case (GH) which is seldom executed - token $token"
+
+		# This will call CancelReadPipeline, CancelWritePipeline, and
+		# cancel any queued requests, responses.
+		Unset $state(socketinfo)
 	    } else {
-		set sock $socketmap($state(socketinfo))
-		Log "reusing socket $sock for $state(socketinfo)"
-		catch {fileevent $sock writable {}}
-		catch {fileevent $sock readable {}}
+		# Use the persistent socket.
+		# The socket may not be ready to write: an earlier request might
+		# still be still writing (in the pipelined case) or
+		# writing/reading (in the nonpipeline case). This possibility
+		# is handled by socketWrQueue later in this command.
+		set reusing 1
+		set sock $socketMapping($state(socketinfo))
+		Log "reusing socket $sock for $state(socketinfo) - token $token"
+
 	    }
+	    # Do not automatically close the connection socket.
+	    set state(connection) {}
 	}
-	# don't automatically close this connection socket
-	set state(connection) {}
     }
+
+    if {$reusing} {
+	# Define state(tmpState) and state(tmpOpenCmd) for use
+	# by http::ReplayIfDead if the persistent connection has died.
+	set state(tmpState) [array get state]
+
+	# Pass -myaddr directly to the socket command
+	if {[info exists state(-myaddr)]} {
+	    lappend sockopts -myaddr $state(-myaddr)
+	}
+
+	set state(tmpOpenCmd) [list {*}$defcmd {*}$sockopts {*}$targetAddr]
+    }
+
+    set state(reusing) $reusing
+    # Excluding ReplayIfDead and the decision whether to call it, there are four
+    # places outside http::geturl where state(reusing) is used:
+    # - Connected   - if reusing and not pipelined, start the state(-timeout)
+    #                 timeout (when writing).
+    # - DoneRequest - if reusing and pipelined, send the next pipelined write
+    # - Event       - if reusing and pipelined, start the state(-timeout)
+    #                 timeout (when reading).
+    # - Event       - if (not reusing) and pipelined, send the next pipelined
+    #                 write
+
+    # See comments above re the start of this timeout in other cases.
+    if {(!$state(reusing)) && ($state(-timeout) > 0)} {
+	set state(after) [after $state(-timeout) \
+		[list http::reset $token timeout]]
+    }
+
     if {![info exists sock]} {
 	# Pass -myaddr directly to the socket command
 	if {[info exists state(-myaddr)]} {
 	    lappend sockopts -myaddr $state(-myaddr)
 	}
-        if {[catch {eval $defcmd $sockopts $targetAddr} sock]} {
-	    # something went wrong while trying to establish the connection.
+	set pre [clock milliseconds]
+	##Log pre socket opened, - token $token
+	##Log [concat $defcmd $sockopts $targetAddr] - token $token
+	if {[catch {eval $defcmd $sockopts $targetAddr} sock errdict]} {
+	    # Something went wrong while trying to establish the connection.
 	    # Clean up after events and such, but DON'T call the command
 	    # callback (if available) because we're going to throw an
 	    # exception from here instead.
 
-	    set state(sock) $sock
-	    Finish $token "" 1
+	    set state(sock) NONE
+	    Finish $token $sock 1
 	    cleanup $token
-	    return -code error $sock
-        }
+	    dict unset errdict -level
+	    return -options $errdict $sock
+	} else {
+	    # Initialisation of a new socket.
+	    ##Log post socket opened, - token $token
+	    ##Log socket opened, now fconfigure - token $token
+	    set delay [expr {[clock milliseconds] - $pre}]
+	    if {$delay > 3000} {
+		Log socket delay $delay - token $token
+	    }
+	    fconfigure $sock -translation {auto crlf} \
+			     -buffersize $state(-blocksize)
+	    ##Log socket opened, DONE fconfigure - token $token
+	}
     }
+    # Command [socket] is called with -async, but takes 5s to 5.1s to return,
+    # with probability of order 1 in 10,000.  This may be a bizarre scheduling
+    # issue with my (KJN's) system (Fedora Linux).
+    # This does not cause a problem (unless the request times out when this
+    # command returns).
+
     set state(sock) $sock
-    Log "Using $sock for $state(socketinfo)" \
-        [expr {$state(-keepalive)?"keepalive":""}]
-    if {$state(-keepalive)} {
-        set socketmap($state(socketinfo)) $sock
+    Log "Using $sock for $state(socketinfo) - token $token" \
+	[expr {$state(-keepalive)?"keepalive":""}]
+
+    if {    $state(-keepalive)
+	 && (![info exists socketMapping($state(socketinfo))])
+    } {
+	# Freshly-opened socket that we would like to become persistent.
+	set socketMapping($state(socketinfo)) $sock
+
+	if {![info exists socketRdState($state(socketinfo))]} {
+	    set socketRdState($state(socketinfo)) {}
+	    set varName ::http::socketRdState($state(socketinfo))
+	    trace add variable $varName unset ::http::CancelReadPipeline
+	}
+	if {![info exists socketWrState($state(socketinfo))]} {
+	    set socketWrState($state(socketinfo)) {}
+	    set varName ::http::socketWrState($state(socketinfo))
+	    trace add variable $varName unset ::http::CancelWritePipeline
+	}
+
+	if {$state(-pipeline)} {
+	    #Log new, init for pipelined, GRANT write access to $token in geturl
+	    # Also grant premature read access to the socket. This is OK.
+	    set socketRdState($state(socketinfo)) $token
+	    set socketWrState($state(socketinfo)) $token
+	} else {
+	    # socketWrState is not used by this non-pipelined transaction.
+	    # We cannot leave it as "Wready" because the next call to
+	    # http::geturl with a pipelined transaction would conclude that the
+	    # socket is available for writing.
+	    #Log new, init for nonpipeline, GRANT r/w access to $token in geturl
+	    set socketRdState($state(socketinfo)) $token
+	    set socketWrState($state(socketinfo)) $token
+	}
+
+	set socketRdQueue($state(socketinfo)) {}
+	set socketWrQueue($state(socketinfo)) {}
+	set socketClosing($state(socketinfo)) 0
+	set socketPlayCmd($state(socketinfo)) {ReplayIfClose Wready {} {}}
     }
 
     if {![info exists phost]} {
 	set phost ""
     }
-    fileevent $sock writable [list http::Connect $token $proto $phost $srvurl]
+    if {$reusing} {
+	# For use by http::ReplayIfDead if the persistent connection has died.
+	# Also used by NextPipelinedWrite.
+	set state(tmpConnArgs) [list $proto $phost $srvurl]
+    }
+
+    # The element socketWrState($connId) has a value which is either the name of
+    # the token that is permitted to write to the socket, or "Wready" if no
+    # token is permitted to write.
+    #
+    # The code that sets the value to Wready immediately calls
+    # http::NextPipelinedWrite, which examines socketWrQueue($connId) and
+    # processes the next request in the queue, if there is one.  The value
+    # Wready is not found when the interpreter is in the event loop unless the
+    # socket is idle.
+    #
+    # The element socketRdState($connId) has a value which is either the name of
+    # the token that is permitted to read from the socket, or "Rready" if no
+    # token is permitted to read.
+    #
+    # The code that sets the value to Rready then examines
+    # socketRdQueue($connId) and processes the next request in the queue, if
+    # there is one.  The value Rready is not found when the interpreter is in
+    # the event loop unless the socket is idle.
+
+    if {$alreadyQueued} {
+	# A write may or may not be in progress.  There is no need to set
+	# socketWrState to prevent another call stealing write access - all
+	# subsequent calls on this socket will come here because the socket
+	# will close after the current read, and its
+	# socketClosing($connId) is 1.
+	##Log "HTTP request for token $token is queued"
+
+    } elseif {    $reusing
+	       && $state(-pipeline)
+	       && ($socketWrState($state(socketinfo)) ne "Wready")
+    } {
+	##Log "HTTP request for token $token is queued for pipelined use"
+	lappend socketWrQueue($state(socketinfo)) $token
+
+    } elseif {    $reusing
+	       && (!$state(-pipeline))
+	       && ($socketWrState($state(socketinfo)) ne "Wready")
+    } {
+	# A write is queued or in progress.  Lappend to the write queue.
+	##Log "HTTP request for token $token is queued for nonpipeline use"
+	lappend socketWrQueue($state(socketinfo)) $token
+
+    } elseif {    $reusing
+	       && (!$state(-pipeline))
+	       && ($socketWrState($state(socketinfo)) eq "Wready")
+	       && ($socketRdState($state(socketinfo)) ne "Rready")
+    } {
+	# A read is queued or in progress, but not a write.  Cannot start the
+	# nonpipeline transaction, but must set socketWrState to prevent a
+	# pipelined request jumping the queue.
+	##Log "HTTP request for token $token is queued for nonpipeline use"
+	#Log re-use nonpipeline, GRANT delayed write access to $token in geturl
+
+	set socketWrState($state(socketinfo)) peNding
+	lappend socketWrQueue($state(socketinfo)) $token
+
+    } else {
+	if {$reusing && $state(-pipeline)} {
+	    #Log re-use pipelined, GRANT write access to $token in geturl
+	    set socketWrState($state(socketinfo)) $token
+
+	} elseif {$reusing} {
+	    # Cf tests above - both are ready.
+	    #Log re-use nonpipeline, GRANT r/w access to $token in geturl
+	    set socketRdState($state(socketinfo)) $token
+	    set socketWrState($state(socketinfo)) $token
+	}
+
+	# All (!$reusing) cases come here, and also some $reusing cases if the
+	# connection is ready.
+	#Log ---- $state(socketinfo) << conn to $token for HTTP request (a)
+	# Connect does its own fconfigure.
+	fileevent $sock writable \
+		[list http::Connect $token $proto $phost $srvurl]
+    }
 
     # Wait for the connection to complete.
     if {![info exists state(-command)]} {
@@ -647,7 +1257,7 @@ proc http::geturl {url args} {
 	    return -code error $err
 	}
     }
-
+    ##Log Leaving http::geturl - token $token
     return $token
 }
 
@@ -657,8 +1267,8 @@ proc http::geturl {url args} {
 #	established.
 #
 # Arguments:
-#       token	State token.
-#       proto	What protocol (http, https, etc.) was used to connect.
+#	token	State token.
+#	proto	What protocol (http, https, etc.) was used to connect.
 #	phost	Are we using keep-alive? Non-empty if yes.
 #	srvurl	Service-local URL that we're requesting
 # Results:
@@ -667,11 +1277,24 @@ proc http::geturl {url args} {
 proc http::Connected {token proto phost srvurl} {
     variable http
     variable urlTypes
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
 
     variable $token
     upvar 0 $token state
+    set tk [namespace tail $token]
+
+    if {$state(reusing) && (!$state(-pipeline)) && ($state(-timeout) > 0)} {
+	set state(after) [after $state(-timeout) \
+		[list http::reset $token timeout]]
+    }
 
-    # Set back the variables needed here
+    # Set back the variables needed here.
     set sock $state(sock)
     set isQueryChannel [info exists state(-querychannel)]
     set isQuery [info exists state(-query)]
@@ -681,9 +1304,12 @@ proc http::Connected {token proto phost srvurl} {
     set lower [string tolower $proto]
     set defport [lindex $urlTypes($lower) 0]
 
-    # Send data in cr-lf format, but accept any line terminators
-
-    fconfigure $sock -translation {auto crlf} -buffersize $state(-blocksize)
+    # Send data in cr-lf format, but accept any line terminators.
+    # Initialisation to {auto *} now done in geturl, KeepSocket and DoneRequest.
+    # We are concerned here with the request (write) not the response (read).
+    lassign [fconfigure $sock -translation] trRead trWrite
+    fconfigure $sock -translation [list $trRead crlf] \
+		     -buffersize $state(-blocksize)
 
     # The following is disallowed in safe interpreters, but the socket is
     # already in non-blocking mode in that case.
@@ -706,10 +1332,12 @@ proc http::Connected {token proto phost srvurl} {
 	set how POST
 	# The query channel must be blocking for the async Write to
 	# work properly.
-	fconfigure $state(-querychannel) -blocking 1 -translation binary
+	lassign [fconfigure $sock -translation] trRead trWrite
+	fconfigure $state(-querychannel) -blocking 1 \
+					 -translation [list $trRead binary]
 	set contDone 0
     }
-    if {[info exists state(-method)] && $state(-method) ne ""} {
+    if {[info exists state(-method)] && ($state(-method) ne "")} {
 	set how $state(-method)
     }
     # We cannot handle chunked encodings with -handler, so force HTTP/1.0
@@ -718,7 +1346,11 @@ proc http::Connected {token proto phost srvurl} {
 	set state(-protocol) 1.0
     }
     set accept_types_seen 0
+
+    Log ^B$tk begin sending request - token $token
+
     if {[catch {
+	set state(method) $how
 	puts $sock "$how $srvurl HTTP/$state(-protocol)"
 	if {[dict exists $state(-headers) Host]} {
 	    # Allow Host spoofing. [Bug 928154]
@@ -731,16 +1363,18 @@ proc http::Connected {token proto phost srvurl} {
 	    puts $sock "Host: $host:$port"
 	}
 	puts $sock "User-Agent: $http(-useragent)"
-        if {$state(-protocol) == 1.0 && $state(-keepalive)} {
+	if {($state(-protocol) >= 1.0) && $state(-keepalive)} {
+	    # Send this header, because a 1.1 server is not compelled to treat
+	    # this as the default.
 	    puts $sock "Connection: keep-alive"
-        }
-        if {$state(-protocol) > 1.0 && !$state(-keepalive)} {
+	}
+	if {($state(-protocol) > 1.0) && !$state(-keepalive)} {
 	    puts $sock "Connection: close" ;# RFC2616 sec 8.1.2.1
-        }
-        if {[info exists phost] && ($phost ne "") && $state(-keepalive)} {
+	}
+	if {[info exists phost] && ($phost ne "") && $state(-keepalive)} {
 	    puts $sock "Proxy-Connection: Keep-Alive"
-        }
-        set accept_encoding_seen 0
+	}
+	set accept_encoding_seen 0
 	set content_type_seen 0
 	dict for {key value} $state(-headers) {
 	    set value [string map [list \n "" \r ""] $value]
@@ -770,10 +1404,13 @@ proc http::Connected {token proto phost srvurl} {
 	if {!$accept_types_seen} {
 	    puts $sock "Accept: $state(accept-types)"
 	}
-        if {!$accept_encoding_seen && ![info exists state(-handler)]} {
+	if {    (!$accept_encoding_seen)
+	     && (![info exists state(-handler)])
+	     && $http(-zip)
+	} {
 	    puts $sock "Accept-Encoding: gzip,deflate,compress"
-        }
-	if {$isQueryChannel && $state(querylength) == 0} {
+	}
+	if {$isQueryChannel && ($state(querylength) == 0)} {
 	    # Try to determine size of data in channel. If we cannot seek, the
 	    # surrounding catch will trap us
 
@@ -802,6 +1439,7 @@ proc http::Connected {token proto phost srvurl} {
 	# response.
 
 	if {$isQuery || $isQueryChannel} {
+	    # POST method.
 	    if {!$content_type_seen} {
 		puts $sock "Content-Type: $state(-type)"
 	    }
@@ -809,29 +1447,753 @@ proc http::Connected {token proto phost srvurl} {
 		puts $sock "Content-Length: $state(querylength)"
 	    }
 	    puts $sock ""
-	    fconfigure $sock -translation {auto binary}
+	    flush $sock
+	    # Flush flushes the error in the https case with a bad handshake:
+	    # else the socket never becomes writable again, and hangs until
+	    # timeout (if any).
+
+	    lassign [fconfigure $sock -translation] trRead trWrite
+	    fconfigure $sock -translation [list $trRead binary]
 	    fileevent $sock writable [list http::Write $token]
+	    # The http::Write command decides when to make the socket readable,
+	    # using the same test as the GET/HEAD case below.
 	} else {
+	    # GET or HEAD method.
+	    if {    (![catch {fileevent $sock readable} binding])
+		 && ($binding eq [list http::CheckEof $sock])
+	    } {
+		# Remove the "fileevent readable" binding of an idle persistent
+		# socket to http::CheckEof.  We can no longer treat bytes
+		# received as junk. The server might still time out and
+		# half-close the socket if it has not yet received the first
+		# "puts".
+		fileevent $sock readable {}
+	    }
 	    puts $sock ""
 	    flush $sock
-	    fileevent $sock readable [list http::Event $sock $token]
+	    Log ^C$tk end sending request - token $token
+	    # End of writing (GET/HEAD methods).  The request has been sent.
+
+	    DoneRequest $token
 	}
 
     } err]} {
-	# The socket probably was never connected, or the connection dropped
-	# later.
+	# The socket probably was never connected, OR the connection dropped
+	# later, OR https handshake error, which may be discovered as late as
+	# the "flush" command above...
+	Log "WARNING - if testing, pay special attention to this\
+		case (GI) which is seldom executed - token $token"
+	if {[info exists state(reusing)] && $state(reusing)} {
+	    # The socket was closed at the server end, and closed at
+	    # this end by http::CheckEof.
+    	    if {[TestForReplay $token write $err a]} {
+		return
+	    } else {
+		Finish $token {failed to re-use socket}
+	    }
 
-	# if state(status) is error, it means someone's already called Finish
-	# to do the above-described clean up.
-	if {$state(status) ne "error"} {
+	    # else:
+	    # This is NOT a persistent socket that has been closed since its
+	    # last use.
+	    # If any other requests are in flight or pipelined/queued, they will
+	    # be discarded.
+	} elseif {$state(status) eq ""} {
+	    # ...https handshake errors come here.
+	    set msg [registerError $sock]
+	    registerError $sock {}
+	    if {$msg eq {}} {
+		set msg {failed to use socket}
+	    }
+	    Finish $token $msg
+	} elseif {$state(status) ne "error"} {
 	    Finish $token $err
 	}
     }
 }
 
+# http::registerError
+#
+#	Called (for example when processing TclTLS activity) to register
+#	an error for a connection on a specific socket.  This helps
+#	http::Connected to deliver meaningful error messages, e.g. when a TLS
+#	certificate fails verification.
+#
+#	Usage: http::registerError socket ?newValue?
+#
+#	"set" semantics, except that a "get" (a call without a new value) for a
+#	non-existent socket returns {}, not an error.
+
+proc http::registerError {sock args} {
+    variable registeredErrors
+
+    if {    ([llength $args] == 0)
+	 && (![info exists registeredErrors($sock)])
+    } {
+	return
+    } elseif {    ([llength $args] == 1)
+	       && ([lindex $args 0] eq {})
+    } {
+	unset -nocomplain registeredErrors($sock)
+	return
+    }
+    set registeredErrors($sock) {*}$args
+}
+
+# http::DoneRequest --
+#
+#	Command called when a request has been sent.  It will arrange the
+#	next request and/or response as appropriate.
+#
+#	If this command is called when $socketClosing(*), the request $token
+#	that calls it must be pipelined and destined to fail.
+
+proc http::DoneRequest {token} {
+    variable http
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
+    variable $token
+    upvar 0 $token state
+    set tk [namespace tail $token]
+    set sock $state(sock)
+
+    # If pipelined, connect the next HTTP request to the socket.
+    if {$state(reusing) && $state(-pipeline)} {
+	# Enable next token (if any) to write.
+	# The value "Wready" is set only here, and
+	# in http::Event after reading the response-headers of a
+	# non-reusing transaction.
+	# Previous value is $token. It cannot be pending.
+	set socketWrState($state(socketinfo)) Wready
+
+	# Now ready to write the next pipelined request (if any).
+	http::NextPipelinedWrite $token
+    } else {
+	# If pipelined, this is the first transaction on this socket.  We wait
+	# for the response headers to discover whether the connection is
+	# persistent.  (If this is not done and the connection is not
+	# persistent, we SHOULD retry and then MUST NOT pipeline before knowing
+	# that we have a persistent connection
+	# (rfc2616 8.1.2.2)).
+    }
+
+    # Connect to receive the response, unless the socket is pipelined
+    # and another response is being sent.
+    # This code block is separate from the code below because there are
+    # cases where socketRdState already has the value $token.
+    if {    $state(-keepalive)
+	 && $state(-pipeline)
+	 && [info exists socketRdState($state(socketinfo))]
+	 && ($socketRdState($state(socketinfo)) eq "Rready")
+    } {
+	#Log pipelined, GRANT read access to $token in Connected
+	set socketRdState($state(socketinfo)) $token
+    }
+
+    if {    $state(-keepalive)
+	 && $state(-pipeline)
+	 && [info exists socketRdState($state(socketinfo))]
+	 && ($socketRdState($state(socketinfo)) ne $token)
+    } {
+	# Do not read from the socket until it is ready.
+	##Log "HTTP response for token $token is queued for pipelined use"
+	# If $socketClosing(*), then the caller will be a pipelined write and
+	# execution will come here.
+	# This token has already been recorded as "in flight" for writing.
+	# When the socket is closed, the read queue will be cleared in
+	# CloseQueuedQueries and so the "lappend" here has no effect.
+	lappend socketRdQueue($state(socketinfo)) $token
+    } else {
+	# In the pipelined case, connection for reading depends on the
+	# value of socketRdState.
+	# In the nonpipeline case, connection for reading always occurs.
+	ReceiveResponse $token
+    }
+}
+
+# http::ReceiveResponse
+#
+#	Connects token to its socket for reading.
+
+proc http::ReceiveResponse {token} {
+    variable $token
+    upvar 0 $token state
+    set tk [namespace tail $token]
+    set sock $state(sock)
+
+    #Log ---- $state(socketinfo) >> conn to $token for HTTP response
+    lassign [fconfigure $sock -translation] trRead trWrite
+    fconfigure $sock -translation [list auto $trWrite] \
+		     -buffersize $state(-blocksize)
+    Log ^D$tk begin receiving response - token $token
+
+    coroutine ${token}EventCoroutine http::Event $sock $token
+    fileevent $sock readable ${token}EventCoroutine
+}
+
+# http::NextPipelinedWrite
+#
+# - Connecting a socket to a token for writing is done by this command and by
+#   command KeepSocket.
+# - If another request has a pipelined write scheduled for $token's socket,
+#   and if the socket is ready to accept it, connect the write and update
+#   the queue accordingly.
+# - This command is called from http::DoneRequest and http::Event,
+#   IF $state(-pipeline) AND (the current transfer has reached the point at
+#   which the socket is ready for the next request to be written).
+# - This command is called when a token has write access and is pipelined and
+#   keep-alive, and sets socketWrState to Wready.
+# - The command need not consider the case where socketWrState is set to a token
+#   that does not yet have write access.  Such a token is waiting for Rready,
+#   and the assignment of the connection to the token will be done elsewhere (in
+#   http::KeepSocket).
+# - This command cannot be called after socketWrState has been set to a
+#   "pending" token value (that is then overwritten by the caller), because that
+#   value is set by this command when it is called by an earlier token when it
+#   relinquishes its write access, and the pending token is always the next in
+#   line to write.
+
+proc http::NextPipelinedWrite {token} {
+    variable http
+    variable socketRdState
+    variable socketWrState
+    variable socketWrQueue
+    variable socketClosing
+    variable $token
+    upvar 0 $token state
+    set connId $state(socketinfo)
+
+    if {    [info exists socketClosing($connId)]
+	 && $socketClosing($connId)
+    } {
+	# socketClosing(*) is set because the server has sent a
+	# "Connection: close" header.
+	# Behave as if the queues are empty - so do nothing.
+    } elseif {    $state(-pipeline)
+	 && [info exists socketWrState($connId)]
+	 && ($socketWrState($connId) eq "Wready")
+
+	 && [info exists socketWrQueue($connId)]
+	 && [llength $socketWrQueue($connId)]
+	 && ([set token2 [lindex $socketWrQueue($connId) 0]
+	      set ${token2}(-pipeline)
+	     ]
+	    )
+    } {
+	# - The usual case for a pipelined connection, ready for a new request.
+	#Log pipelined, GRANT write access to $token2 in NextPipelinedWrite
+	set conn [set ${token2}(tmpConnArgs)]
+	set socketWrState($connId) $token2
+	set socketWrQueue($connId) [lrange $socketWrQueue($connId) 1 end]
+	# Connect does its own fconfigure.
+	fileevent $state(sock) writable [list http::Connect $token2 {*}$conn]
+	#Log ---- $connId << conn to $token2 for HTTP request (b)
+
+	# In the tests below, the next request will be nonpipeline.
+    } elseif {    $state(-pipeline)
+	       && [info exists socketWrState($connId)]
+	       && ($socketWrState($connId) eq "Wready")
+
+	       && [info exists socketWrQueue($connId)]
+	       && [llength $socketWrQueue($connId)]
+	       && (![ set token3 [lindex $socketWrQueue($connId) 0]
+		      set ${token3}(-pipeline)
+		    ]
+		  )
+
+	       && [info exists socketRdState($connId)]
+	       && ($socketRdState($connId) eq "Rready")
+    } {
+	# The case in which the next request will be non-pipelined, and the read
+	# and write queues is ready: which is the condition for a non-pipelined
+	# write.
+	variable $token3
+	upvar 0 $token3 state3
+	set conn [set ${token3}(tmpConnArgs)]
+	#Log nonpipeline, GRANT r/w access to $token3 in NextPipelinedWrite
+	set socketRdState($connId) $token3
+	set socketWrState($connId) $token3
+	set socketWrQueue($connId) [lrange $socketWrQueue($connId) 1 end]
+	# Connect does its own fconfigure.
+	fileevent $state(sock) writable [list http::Connect $token3 {*}$conn]
+	#Log ---- $state(sock) << conn to $token3 for HTTP request (c)
+
+    } elseif {    $state(-pipeline)
+	 && [info exists socketWrState($connId)]
+	 && ($socketWrState($connId) eq "Wready")
+
+	 && [info exists socketWrQueue($connId)]
+	 && [llength $socketWrQueue($connId)]
+	 && (![set token2 [lindex $socketWrQueue($connId) 0]
+	      set ${token2}(-pipeline)
+	     ]
+	    )
+    } {
+	# - The case in which the next request will be non-pipelined, but the
+	#   read queue is NOT ready.
+	# - A read is queued or in progress, but not a write.  Cannot start the
+	#   nonpipeline transaction, but must set socketWrState to prevent a new
+	#   pipelined request (in http::geturl) jumping the queue.
+	# - Because socketWrState($connId) is not set to Wready, the assignment
+	#   of the connection to $token2 will be done elsewhere - by command
+	#   http::KeepSocket when $socketRdState($connId) is set to "Rready".
+
+	#Log re-use nonpipeline, GRANT delayed write access to $token in NextP..
+	set socketWrState($connId) peNding
+    }
+}
+
+# http::CancelReadPipeline
+#
+#	Cancel pipelined responses on a closing "Keep-Alive" socket.
+#
+#	- Called by a variable trace on "unset socketRdState($connId)".
+#	- The variable relates to a Keep-Alive socket, which has been closed.
+#	- Cancels all pipelined responses. The requests have been sent,
+#	  the responses have not yet been received.
+#	- This is a hard cancel that ends each transaction with error status,
+#	  and closes the connection. Do not use it if you want to replay failed
+#	  transactions.
+#	- N.B. Always delete ::http::socketRdState($connId) before deleting
+#	  ::http::socketRdQueue($connId), or this command will do nothing.
+#
+# Arguments
+#	As for a trace command on a variable.
+
+proc http::CancelReadPipeline {name1 connId op} {
+    variable socketRdQueue
+    ##Log CancelReadPipeline $name1 $connId $op
+    if {[info exists socketRdQueue($connId)]} {
+	set msg {the connection was closed by CancelReadPipeline}
+	foreach token $socketRdQueue($connId) {
+	    set tk [namespace tail $token]
+	    Log ^X$tk end of response "($msg)" - token $token
+	    set ${token}(status) eof
+	    Finish $token ;#$msg
+	}
+	set socketRdQueue($connId) {}
+    }
+}
+
+# http::CancelWritePipeline
+#
+#	Cancel queued events on a closing "Keep-Alive" socket.
+#
+#	- Called by a variable trace on "unset socketWrState($connId)".
+#	- The variable relates to a Keep-Alive socket, which has been closed.
+#	- In pipelined or nonpipeline case: cancels all queued requests.  The
+#	  requests have not yet been sent, the responses are not due.
+#	- This is a hard cancel that ends each transaction with error status,
+#	  and closes the connection. Do not use it if you want to replay failed
+#	  transactions.
+#	- N.B. Always delete ::http::socketWrState($connId) before deleting
+#	  ::http::socketWrQueue($connId), or this command will do nothing.
+#
+# Arguments
+#	As for a trace command on a variable.
+
+proc http::CancelWritePipeline {name1 connId op} {
+    variable socketWrQueue
+
+    ##Log CancelWritePipeline $name1 $connId $op
+    if {[info exists socketWrQueue($connId)]} {
+	set msg {the connection was closed by CancelWritePipeline}
+	foreach token $socketWrQueue($connId) {
+	    set tk [namespace tail $token]
+	    Log ^X$tk end of response "($msg)" - token $token
+	    set ${token}(status) eof
+	    Finish $token ;#$msg
+	}
+	set socketWrQueue($connId) {}
+    }
+}
+
+# http::ReplayIfDead --
+#
+# - A query on a re-used persistent socket failed at the earliest opportunity,
+#   because the socket had been closed by the server.  Keep the token, tidy up,
+#   and try to connect on a fresh socket.
+# - The connection is monitored for eof by the command http::CheckEof.  Thus
+#   http::ReplayIfDead is needed only when a server event (half-closing an
+#   apparently idle connection), and a client event (sending a request) occur at
+#   almost the same time, and neither client nor server detects the other's
+#   action before performing its own (an "asynchronous close event").
+# - To simplify testing of http::ReplayIfDead, set TEST_EOF 1 in
+#   http::KeepSocket, and then http::ReplayIfDead will be called if http::geturl
+#   is called at any time after the server timeout.
+#
+# Arguments:
+#	token	Connection token.
+#
+# Side Effects:
+#	Use the same token, but try to open a new socket.
+
+proc http::ReplayIfDead {tokenArg doing} {
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
+    variable $tokenArg
+    upvar 0 $tokenArg stateArg
+
+    Log running http::ReplayIfDead for $tokenArg $doing
+
+    # 1. Merge the tokens for transactions in flight, the read (response) queue,
+    #    and the write (request) queue.
+
+    set InFlightR {}
+    set InFlightW {}
+
+    # Obtain the tokens for transactions in flight.
+    if {$stateArg(-pipeline)} {
+	# Two transactions may be in flight.  The "read" transaction was first.
+	# It is unlikely that the server would close the socket if a response
+	# was pending; however, an earlier request (as well as the present
+	# request) may have been sent and ignored if the socket was half-closed
+	# by the server.
+
+	if {    [info exists socketRdState($stateArg(socketinfo))]
+	     && ($socketRdState($stateArg(socketinfo)) ne "Rready")
+	} {
+	    lappend InFlightR $socketRdState($stateArg(socketinfo))
+	} elseif {($doing eq "read")} {
+	    lappend InFlightR $tokenArg
+	}
+
+	if {    [info exists socketWrState($stateArg(socketinfo))]
+	     && $socketWrState($stateArg(socketinfo)) ni {Wready peNding}
+	} {
+	    lappend InFlightW $socketWrState($stateArg(socketinfo))
+	} elseif {($doing eq "write")} {
+	    lappend InFlightW $tokenArg
+	}
+
+	# Report any inconsistency of $tokenArg with socket*state.
+	if {    ($doing eq "read")
+	     && [info exists socketRdState($stateArg(socketinfo))]
+	     && ($tokenArg ne $socketRdState($stateArg(socketinfo)))
+	} {
+	    Log WARNING - ReplayIfDead pipelined tokenArg $tokenArg $doing \
+		    ne socketRdState($stateArg(socketinfo)) \
+		      $socketRdState($stateArg(socketinfo))
+
+	} elseif {
+		($doing eq "write")
+	     && [info exists socketWrState($stateArg(socketinfo))]
+	     && ($tokenArg ne $socketWrState($stateArg(socketinfo)))
+	} {
+	    Log WARNING - ReplayIfDead pipelined tokenArg $tokenArg $doing \
+		    ne socketWrState($stateArg(socketinfo)) \
+		      $socketWrState($stateArg(socketinfo))
+	}
+    } else {
+	# One transaction should be in flight.
+	# socketRdState, socketWrQueue are used.
+	# socketRdQueue should be empty.
+
+	# Report any inconsistency of $tokenArg with socket*state.
+	if {$tokenArg ne $socketRdState($stateArg(socketinfo))} {
+	    Log WARNING - ReplayIfDead nonpipeline tokenArg $tokenArg $doing \
+		    ne socketRdState($stateArg(socketinfo)) \
+		      $socketRdState($stateArg(socketinfo))
+	}
+
+	# Report the inconsistency that socketRdQueue is non-empty.
+	if {    [info exists socketRdQueue($stateArg(socketinfo))]
+	     && ($socketRdQueue($stateArg(socketinfo)) ne {})
+	} {
+	    Log WARNING - ReplayIfDead nonpipeline tokenArg $tokenArg $doing \
+		    has read queue socketRdQueue($stateArg(socketinfo)) \
+		    $socketRdQueue($stateArg(socketinfo)) ne {}
+	}
+
+	lappend InFlightW $socketRdState($stateArg(socketinfo))
+	set socketRdQueue($stateArg(socketinfo)) {}
+    }
+
+    set newQueue {}
+    lappend newQueue {*}$InFlightR
+    lappend newQueue {*}$socketRdQueue($stateArg(socketinfo))
+    lappend newQueue {*}$InFlightW
+    lappend newQueue {*}$socketWrQueue($stateArg(socketinfo))
+
+
+    # 2. Tidy up tokenArg.  This is a cut-down form of Finish/CloseSocket.
+    #    Do not change state(status).
+    #    No need to after cancel stateArg(after) - either this is done in
+    #    ReplayCore/ReInit, or Finish is called.
+
+    catch {close $stateArg(sock)}
+
+    # 2a. Tidy the tokens in the queues - this is done in ReplayCore/ReInit.
+    # - Transactions, if any, that are awaiting responses cannot be completed.
+    #   They are listed for re-sending in newQueue.
+    # - All tokens are preserved for re-use by ReplayCore, and their variables
+    #   will be re-initialised by calls to ReInit.
+    # - The relevant element of socketMapping, socketRdState, socketWrState,
+    #   socketRdQueue, socketWrQueue, socketClosing, socketPlayCmd will be set
+    #   to new values in ReplayCore.
+
+    ReplayCore $newQueue
+}
+
+# http::ReplayIfClose --
+#
+#	A request on a socket that was previously "Connection: keep-alive" has
+#	received a "Connection: close" response header.  The server supplies
+#	that response correctly, but any later requests already queued on this
+#	connection will be lost when the socket closes.
+#
+#	This command takes arguments that represent the socketWrState,
+#	socketRdQueue and socketWrQueue for this connection.  The socketRdState
+#	is not needed because the server responds in full to the request that
+#	received the "Connection: close" response header.
+#
+#	Existing request tokens $token (::http::$n) are preserved.  The caller
+#	will be unaware that the request was processed this way.
+
+proc http::ReplayIfClose {Wstate Rqueue Wqueue} {
+    Log running http::ReplayIfClose for $Wstate $Rqueue $Wqueue
+
+    if {$Wstate in $Rqueue || $Wstate in $Wqueue} {
+	Log WARNING duplicate token in http::ReplayIfClose - token $Wstate
+	set Wstate Wready
+    }
+
+    # 1. Create newQueue
+    set InFlightW {}
+    if {$Wstate ni {Wready peNding}} {
+	lappend InFlightW $Wstate
+    }
+
+    set newQueue {}
+    lappend newQueue {*}$Rqueue
+    lappend newQueue {*}$InFlightW
+    lappend newQueue {*}$Wqueue
+
+    # 2. Cleanup - none needed, done by the caller.
+
+    ReplayCore $newQueue
+}
+
+# http::ReInit --
+#
+#	Command to restore a token's state to a condition that
+#	makes it ready to replay a request.
+#
+#	Command http::geturl stores extra state in state(tmp*) so
+#	we don't need to do the argument processing again.
+#
+#	The caller must:
+#	- Set state(reusing) and state(sock) to their new values after calling
+#	  this command.
+#	- Unset state(tmpState), state(tmpOpenCmd) if future calls to ReplayCore
+#	  or ReInit are inappropriate for this token. Typically only one retry
+#	  is allowed.
+#	The caller may also unset state(tmpConnArgs) if this value (and the
+#	token) will be used immediately.  The value is needed by tokens that
+#	will be stored in a queue.
+#
+# Arguments:
+#	token	Connection token.
+#
+# Return Value: (boolean) true iff the re-initialisation was successful.
+
+proc http::ReInit {token} {
+    variable $token
+    upvar 0 $token state
+
+    if {!(
+	      [info exists state(tmpState)]
+	   && [info exists state(tmpOpenCmd)]
+	   && [info exists state(tmpConnArgs)]
+	 )
+    } {
+	Log FAILED in http::ReInit via ReplayCore - NO tmp vars for $token
+	return 0
+    }
+
+    if {[info exists state(after)]} {
+	after cancel $state(after)
+	unset state(after)
+    }
+
+    # Don't alter state(status) - this would trigger http::wait if it is in use.
+    set tmpState    $state(tmpState)
+    set tmpOpenCmd  $state(tmpOpenCmd)
+    set tmpConnArgs $state(tmpConnArgs)
+    foreach name [array names state] {
+	if {$name ne "status"} {
+	    unset state($name)
+	}
+    }
+
+    # Don't alter state(status).
+    # Restore state(tmp*) - the caller may decide to unset them.
+    # Restore state(tmpConnArgs) which is needed for connection.
+    # state(tmpState), state(tmpOpenCmd) are needed only for retries.
+
+    dict unset tmpState status
+    array set state $tmpState
+    set state(tmpState)    $tmpState
+    set state(tmpOpenCmd)  $tmpOpenCmd
+    set state(tmpConnArgs) $tmpConnArgs
+
+    return 1
+}
+
+# http::ReplayCore --
+#
+#	Command to replay a list of requests, using existing connection tokens.
+#
+#	Abstracted from http::geturl which stores extra state in state(tmp*) so
+#	we don't need to do the argument processing again.
+#
+# Arguments:
+#	newQueue	List of connection tokens.
+#
+# Side Effects:
+#	Use existing tokens, but try to open a new socket.
+
+proc http::ReplayCore {newQueue} {
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
+    if {[llength $newQueue] == 0} {
+	# Nothing to do.
+	return
+    }
+
+    ##Log running ReplayCore for {*}$newQueue
+    set newToken [lindex $newQueue 0]
+    set newQueue [lrange $newQueue 1 end]
+
+    # 3. Use newToken, and restore its values of state(*).  Do not restore
+    #    elements tmp* - we try again only once.
+
+    set token $newToken
+    variable $token
+    upvar 0 $token state
+
+    if {![ReInit $token]} {
+	Log FAILED in http::ReplayCore - NO tmp vars
+	Finish $token {cannot send this request again}
+	return
+    }
+
+    set tmpState    $state(tmpState)
+    set tmpOpenCmd  $state(tmpOpenCmd)
+    set tmpConnArgs $state(tmpConnArgs)
+    unset state(tmpState)
+    unset state(tmpOpenCmd)
+    unset state(tmpConnArgs)
+
+    set state(reusing) 0
+
+    if {$state(-timeout) > 0} {
+	set resetCmd [list http::reset $token timeout]
+	set state(after) [after $state(-timeout) $resetCmd]
+    }
+
+    set pre [clock milliseconds]
+    ##Log pre socket opened, - token $token
+    ##Log $tmpOpenCmd - token $token
+    # 4. Open a socket.
+    if {[catch {eval $tmpOpenCmd} sock]} {
+	# Something went wrong while trying to establish the connection.
+	Log FAILED - $sock
+	set state(sock) NONE
+	Finish $token $sock
+	return
+    }
+    ##Log post socket opened, - token $token
+    set delay [expr {[clock milliseconds] - $pre}]
+    if {$delay > 3000} {
+	Log socket delay $delay - token $token
+    }
+    # Command [socket] is called with -async, but takes 5s to 5.1s to return,
+    # with probability of order 1 in 10,000.  This may be a bizarre scheduling
+    # issue with my (KJN's) system (Fedora Linux).
+    # This does not cause a problem (unless the request times out when this
+    # command returns).
+
+    # 5. Configure the persistent socket data.
+    if {$state(-keepalive)} {
+	set socketMapping($state(socketinfo)) $sock
+
+	if {![info exists socketRdState($state(socketinfo))]} {
+	    set socketRdState($state(socketinfo)) {}
+	    set varName ::http::socketRdState($state(socketinfo))
+	    trace add variable $varName unset ::http::CancelReadPipeline
+	}
+
+	if {![info exists socketWrState($state(socketinfo))]} {
+	    set socketWrState($state(socketinfo)) {}
+	    set varName ::http::socketWrState($state(socketinfo))
+	    trace add variable $varName unset ::http::CancelWritePipeline
+	}
+
+	if {$state(-pipeline)} {
+	    #Log new, init for pipelined, GRANT write acc to $token ReplayCore
+	    set socketRdState($state(socketinfo)) $token
+	    set socketWrState($state(socketinfo)) $token
+	} else {
+	    #Log new, init for nonpipeline, GRANT r/w acc to $token ReplayCore
+	    set socketRdState($state(socketinfo)) $token
+	    set socketWrState($state(socketinfo)) $token
+	}
+
+	set socketRdQueue($state(socketinfo)) {}
+	set socketWrQueue($state(socketinfo)) $newQueue
+	set socketClosing($state(socketinfo)) 0
+	set socketPlayCmd($state(socketinfo)) {ReplayIfClose Wready {} {}}
+    }
+
+    ##Log pre newQueue ReInit, - token $token
+    # 6. Configure sockets in the queue.
+    foreach tok $newQueue {
+	if {[ReInit $tok]} {
+	    set ${tok}(reusing) 1
+	    set ${tok}(sock) $sock
+	} else {
+	    set ${tok}(reusing) 1
+	    set ${tok}(sock) NONE
+	    Finish $token {cannot send this request again}
+	}
+    }
+
+    # 7. Configure the socket for newToken to send a request.
+    set state(sock) $sock
+    Log "Using $sock for $state(socketinfo) - token $token" \
+	[expr {$state(-keepalive)?"keepalive":""}]
+
+    # Initialisation of a new socket.
+    ##Log socket opened, now fconfigure - token $token
+    fconfigure $sock -translation {auto crlf} -buffersize $state(-blocksize)
+    ##Log socket opened, DONE fconfigure - token $token
+
+    # Connect does its own fconfigure.
+    fileevent $sock writable [list http::Connect $token {*}$tmpConnArgs]
+    #Log ---- $sock << conn to $token for HTTP request (e)
+}
+
 # Data access functions:
 # Data - the URL data
-# Status - the transaction status: ok, reset, eof, timeout
+# Status - the transaction status: ok, reset, eof, timeout, error
 # Code - the HTTP transaction code, e.g., 200
 # Size - the size of the URL data
 
@@ -894,6 +2256,13 @@ proc http::error {token} {
 proc http::cleanup {token} {
     variable $token
     upvar 0 $token state
+    if {[info commands ${token}EventCoroutine] ne {}} {
+	rename ${token}EventCoroutine {}
+    }
+    if {[info exists state(after)]} {
+	after cancel $state(after)
+	unset state(after)
+    }
     if {[info exists state]} {
 	unset state
     }
@@ -913,17 +2282,33 @@ proc http::cleanup {token} {
 proc http::Connect {token proto phost srvurl} {
     variable $token
     upvar 0 $token state
+    set tk [namespace tail $token]
     set err "due to unexpected EOF"
     if {
 	[eof $state(sock)] ||
 	[set err [fconfigure $state(sock) -error]] ne ""
     } {
+	Log "WARNING - if testing, pay special attention to this\
+		case (GJ) which is seldom executed - token $token"
+	if {[info exists state(reusing)] && $state(reusing)} {
+	    # The socket was closed at the server end, and closed at
+	    # this end by http::CheckEof.
+	    if {[TestForReplay $token write $err b]} {
+		return
+	    }
+
+	    # else:
+	    # This is NOT a persistent socket that has been closed since its
+	    # last use.
+	    # If any other requests are in flight or pipelined/queued, they will
+	    # be discarded.
+	}
 	Finish $token "connect failed $err"
     } else {
+	set state(state) connecting
 	fileevent $state(sock) writable {}
 	::http::Connected $token $proto $phost $srvurl
     }
-    return
 }
 
 # http::Write
@@ -937,8 +2322,18 @@ proc http::Connect {token proto phost srvurl} {
 #	Write the socket and handle callbacks.
 
 proc http::Write {token} {
+    variable http
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
     variable $token
     upvar 0 $token state
+    set tk [namespace tail $token]
     set sock $state(sock)
 
     # Output a block.  Tcl will buffer this if the socket blocks
@@ -949,7 +2344,21 @@ proc http::Write {token} {
 	if {[info exists state(-query)]} {
 	    # Chop up large query strings so queryprogress callback can give
 	    # smooth feedback.
-
+	    if {    $state(queryoffset) + $state(-queryblocksize)
+		 >= $state(querylength)
+	    } {
+		# This will be the last puts for the request-body.
+		if {    (![catch {fileevent $sock readable} binding])
+		     && ($binding eq [list http::CheckEof $sock])
+		} {
+		    # Remove the "fileevent readable" binding of an idle
+		    # persistent socket to http::CheckEof.  We can no longer
+		    # treat bytes received as junk. The server might still time
+		    # out and half-close the socket if it has not yet received
+		    # the first "puts".
+		    fileevent $sock readable {}
+		}
+	    }
 	    puts -nonewline $sock \
 		[string range $state(-query) $state(queryoffset) \
 		     [expr {$state(queryoffset) + $state(-queryblocksize) - 1}]]
@@ -962,6 +2371,19 @@ proc http::Write {token} {
 	    # Copy blocks from the query channel
 
 	    set outStr [read $state(-querychannel) $state(-queryblocksize)]
+	    if {[eof $state(-querychannel)]} {
+		# This will be the last puts for the request-body.
+		if {    (![catch {fileevent $sock readable} binding])
+		     && ($binding eq [list http::CheckEof $sock])
+		} {
+		    # Remove the "fileevent readable" binding of an idle
+		    # persistent socket to http::CheckEof.  We can no longer
+		    # treat bytes received as junk. The server might still time
+		    # out and half-close the socket if it has not yet received
+		    # the first "puts".
+		    fileevent $sock readable {}
+		}
+	    }
 	    puts -nonewline $sock $outStr
 	    incr state(queryoffset) [string length $outStr]
 	    if {[eof $state(-querychannel)]} {
@@ -975,10 +2397,14 @@ proc http::Write {token} {
 	set state(posterror) $err
 	set done 1
     }
+
     if {$done} {
 	catch {flush $sock}
 	fileevent $sock writable {}
-	fileevent $sock readable [list http::Event $sock $token]
+	Log ^C$tk end sending request - token $token
+	# End of writing (POST method).  The request has been sent.
+
+	DoneRequest $token
     }
 
     # Callback to the client after we've completely handled everything.
@@ -991,7 +2417,9 @@ proc http::Write {token} {
 
 # http::Event
 #
-#	Handle input on the socket
+#	Handle input on the socket. This command is the core of
+#	the coroutine commands ${token}EventCoroutine that are
+#	bound to "fileevent $sock readable" and process input.
 #
 # Arguments
 #	sock	The socket receiving input.
@@ -1001,196 +2429,532 @@ proc http::Write {token} {
 #	Read the socket and handle callbacks.
 
 proc http::Event {sock token} {
+    variable http
+    variable socketMapping
+    variable socketRdState
+    variable socketWrState
+    variable socketRdQueue
+    variable socketWrQueue
+    variable socketClosing
+    variable socketPlayCmd
+
     variable $token
     upvar 0 $token state
+    set tk [namespace tail $token]
+    while 1 {
+	yield
+	##Log Event call - token $token
 
-    if {![info exists state]} {
-	Log "Event $sock with invalid token '$token' - remote close?"
-	if {![eof $sock]} {
-	    if {[set d [read $sock]] ne ""} {
-		Log "WARNING: additional data left on closed socket"
+	if {![info exists state]} {
+	    Log "Event $sock with invalid token '$token' - remote close?"
+	    if {![eof $sock]} {
+		if {[set d [read $sock]] ne ""} {
+		    Log "WARNING: additional data left on closed socket\
+			    - token $token"
+		}
 	    }
+	    Log ^X$tk end of response (token error) - token $token
+	    CloseSocket $sock
+	    return
 	}
-	CloseSocket $sock
-	return
-    }
-    if {$state(state) eq "connecting"} {
-	if {[catch {gets $sock state(http)} n]} {
-	    return [Finish $token $n]
-	} elseif {$n >= 0} {
-	    set state(state) "header"
-	}
-    } elseif {$state(state) eq "header"} {
-	if {[catch {gets $sock line} n]} {
-	    return [Finish $token $n]
-	} elseif {$n == 0} {
-	    # We have now read all headers
-	    # We ignore HTTP/1.1 100 Continue returns. RFC2616 sec 8.2.3
-	    if {$state(http) == "" || ([regexp {^\S+\s(\d+)} $state(http) {} x] && $x == 100)} {
-		set state(state) "connecting"
-		return
+	if {$state(state) eq "connecting"} {
+	    ##Log - connecting - token $token
+	    if {    $state(reusing)
+		 && $state(-pipeline)
+		 && ($state(-timeout) > 0)
+		 && (![info exists state(after)])
+	    } {
+		set state(after) [after $state(-timeout) \
+			[list http::reset $token timeout]]
 	    }
 
-	    set state(state) body
+	    if {[catch {gets $sock state(http)} nsl]} {
+		Log "WARNING - if testing, pay special attention to this\
+			case (GK) which is seldom executed - token $token"
+		if {[info exists state(reusing)] && $state(reusing)} {
+		    # The socket was closed at the server end, and closed at
+		    # this end by http::CheckEof.
 
-	    # If doing a HEAD, then we won't get any body
-	    if {$state(-validate)} {
-		Eof $token
-		return
-	    }
+		    if {[TestForReplay $token read $nsl c]} {
+			return
+		    }
 
-	    # For non-chunked transfer we may have no body - in this case we
-	    # may get no further file event if the connection doesn't close
-	    # and no more data is sent. We can tell and must finish up now -
-	    # not later.
-	    if {
-		!(([info exists state(connection)]
-			&& ($state(connection) eq "close"))
-		    || [info exists state(transfer)])
-		&& ($state(totalsize) == 0)
+		    # else:
+		    # This is NOT a persistent socket that has been closed since
+		    # its last use.
+		    # If any other requests are in flight or pipelined/queued,
+		    # they will be discarded.
+		} else {
+		    Log ^X$tk end of response (error) - token $token
+		    Finish $token $nsl
+		    return
+		}
+	    } elseif {$nsl >= 0} {
+		##Log - connecting 1 - token $token
+		set state(state) "header"
+	    } elseif {    [eof $sock]
+		       && [info exists state(reusing)]
+		       && $state(reusing)
 	    } {
-		Log "body size is 0 and no events likely - complete."
-		Eof $token
-		return
-	    }
+		# The socket was closed at the server end, and we didn't notice.
+		# This is the first read - where the closure is usually first
+		# detected.
 
-	    # We have to use binary translation to count bytes properly.
-	    fconfigure $sock -translation binary
+		if {[TestForReplay $token read {} d]} {
+		    return
+		}
 
-	    if {
-		$state(-binary) || [IsBinaryContentType $state(type)]
-	    } {
-		# Turn off conversions for non-text data
-		set state(binary) 1
+		# else:
+		# This is NOT a persistent socket that has been closed since its
+		# last use.
+		# If any other requests are in flight or pipelined/queued, they
+		# will be discarded.
 	    }
-	    if {[info exists state(-channel)]} {
-		if {$state(binary) || [llength [ContentEncoding $token]]} {
-		    fconfigure $state(-channel) -translation binary
+	} elseif {$state(state) eq "header"} {
+	    if {[catch {gets $sock line} nhl]} {
+		##Log header failed - token $token
+		Log ^X$tk end of response (error) - token $token
+		Finish $token $nhl
+		return
+	    } elseif {$nhl == 0} {
+		##Log header done - token $token
+		Log ^E$tk end of response headers - token $token
+		# We have now read all headers
+		# We ignore HTTP/1.1 100 Continue returns. RFC2616 sec 8.2.3
+		if {    ($state(http) == "")
+		     || ([regexp {^\S+\s(\d+)} $state(http) {} x] && $x == 100)
+		} {
+		    set state(state) "connecting"
+		    continue
+		    # This was a "return" in the pre-coroutine code.
 		}
-		if {![info exists state(-handler)]} {
-		    # Initiate a sequence of background fcopies
-		    fileevent $sock readable {}
-		    CopyStart $sock $token
-		    return
+
+		if {    ([info exists state(connection)])
+		     && ([info exists socketMapping($state(socketinfo))])
+		     && ($state(connection) eq "keep-alive")
+		     && ($state(-keepalive))
+		     && (!$state(reusing))
+		     && ($state(-pipeline))
+		} {
+		    # Response headers received for first request on a
+		    # persistent socket.  Now ready for pipelined writes (if
+		    # any).
+		    # Previous value is $token. It cannot be "pending".
+		    set socketWrState($state(socketinfo)) Wready
+		    http::NextPipelinedWrite $token
 		}
-	    }
-	} elseif {$n > 0} {
-	    # Process header lines
-	    if {[regexp -nocase {^([^:]+):(.+)$} $line x key value]} {
-		switch -- [string tolower $key] {
-		    content-type {
-			set state(type) [string trim [string tolower $value]]
-			# grab the optional charset information
-			if {[regexp -nocase \
-				 {charset\s*=\s*\"((?:[^""]|\\\")*)\"} \
-				 $state(type) -> cs]} {
-			    set state(charset) [string map {{\"} \"} $cs]
+
+		# Once a "close" has been signaled, the client MUST NOT send any
+		# more requests on that connection.
+		#
+		# If either the client or the server sends the "close" token in
+		# the Connection header, that request becomes the last one for
+		# the connection.
+
+		if {    ([info exists state(connection)])
+		     && ([info exists socketMapping($state(socketinfo))])
+		     && ($state(connection) eq "close")
+		     && ($state(-keepalive))
+		} {
+		    # The server warns that it will close the socket after this
+		    # response.
+		    ##Log WARNING - socket will close after response for $token
+		    # Prepare data for a call to ReplayIfClose.
+		    if {    ($socketRdQueue($state(socketinfo)) ne {})
+			 || ($socketWrQueue($state(socketinfo)) ne {})
+			 || ($socketWrState($state(socketinfo)) ni
+						[list Wready peNding $token])
+		    } {
+			set InFlightW $socketWrState($state(socketinfo))
+			if {$InFlightW in [list Wready peNding $token]} {
+			    set InFlightW Wready
 			} else {
-			    regexp -nocase {charset\s*=\s*(\S+?);?} \
-				$state(type) -> state(charset)
+			    set msg "token ${InFlightW} is InFlightW"
+			    ##Log $msg - token $token
 			}
+
+			set socketPlayCmd($state(socketinfo)) \
+				[list ReplayIfClose $InFlightW \
+				$socketRdQueue($state(socketinfo)) \
+				$socketWrQueue($state(socketinfo))]
+
+			# - All tokens are preserved for re-use by ReplayCore.
+			# - Queues are preserved in case of Finish with error,
+			#   but are not used for anything else because
+			#   socketClosing(*) is set below.
+			# - Cancel the state(after) timeout events.
+			foreach tokenVal $socketRdQueue($state(socketinfo)) {
+			    if {[info exists ${tokenVal}(after)]} {
+				after cancel [set ${tokenVal}(after)]
+				unset ${tokenVal}(after)
+			    }
+			}
+
+		    } else {
+			set socketPlayCmd($state(socketinfo)) \
+				{ReplayIfClose Wready {} {}}
 		    }
-		    content-length {
-			set state(totalsize) [string trim $value]
-		    }
-		    content-encoding {
-			set state(coding) [string trim $value]
+
+		    # Do not allow further connections on this socket.
+		    set socketClosing($state(socketinfo)) 1
+		}
+
+		set state(state) body
+
+		# If doing a HEAD, then we won't get any body
+		if {$state(-validate)} {
+		    Log ^F$tk end of response for HEAD request - token $token
+		    set state(state) complete
+		    Eot $token
+		    return
+		}
+
+		# - For non-chunked transfer we may have no body - in this case
+		#   we may get no further file event if the connection doesn't
+		#   close and no more data is sent. We can tell and must finish
+		#   up now - not later - the alternative would be to wait until
+		#   the server times out.
+		# - In this case, the server has NOT told the client it will
+		#   close the connection, AND it has NOT indicated the resource
+		#   length EITHER by setting the Content-Length (totalsize) OR
+		#   by using chunked Transfer-Encoding.
+		# - Do not worry here about the case (Connection: close) because
+		#   the server should close the connection.
+		# - IF (NOT Connection: close) AND (NOT chunked encoding) AND
+		#      (totalsize == 0).
+
+		if {    (!(    [info exists state(connection)]
+			    && ($state(connection) eq "close")
+			  )
+			)
+		     && (![info exists state(transfer)])
+		     && ($state(totalsize) == 0)
+		} {
+		    set msg {body size is 0 and no events likely - complete}
+		    Log "$msg - token $token"
+		    set msg {(length unknown, set to 0)}
+		    Log ^F$tk end of response body {*}$msg - token $token
+		    set state(state) complete
+		    Eot $token
+		    return
+		}
+
+		# We have to use binary translation to count bytes properly.
+		lassign [fconfigure $sock -translation] trRead trWrite
+		fconfigure $sock -translation [list binary $trWrite]
+
+		if {
+		    $state(-binary) || [IsBinaryContentType $state(type)]
+		} {
+		    # Turn off conversions for non-text data.
+		    set state(binary) 1
+		}
+		if {[info exists state(-channel)]} {
+		    if {$state(binary) || [llength [ContentEncoding $token]]} {
+			fconfigure $state(-channel) -translation binary
 		    }
-		    transfer-encoding {
-			set state(transfer) \
-			    [string trim [string tolower $value]]
+		    if {![info exists state(-handler)]} {
+			# Initiate a sequence of background fcopies.
+			fileevent $sock readable {}
+			rename ${token}EventCoroutine {}
+			CopyStart $sock $token
+			return
 		    }
-		    proxy-connection -
-		    connection {
-			set state(connection) \
-			    [string trim [string tolower $value]]
+		}
+	    } elseif {$nhl > 0} {
+		# Process header lines.
+		##Log header - token $token - $line
+		if {[regexp -nocase {^([^:]+):(.+)$} $line x key value]} {
+		    switch -- [string tolower $key] {
+			content-type {
+			    set state(type) [string trim [string tolower $value]]
+			    # Grab the optional charset information.
+			    if {[regexp -nocase \
+				    {charset\s*=\s*\"((?:[^""]|\\\")*)\"} \
+				    $state(type) -> cs]} {
+				set state(charset) [string map {{\"} \"} $cs]
+			    } else {
+				regexp -nocase {charset\s*=\s*(\S+?);?} \
+					$state(type) -> state(charset)
+			    }
+			}
+			content-length {
+			    set state(totalsize) [string trim $value]
+			}
+			content-encoding {
+			    set state(coding) [string trim $value]
+			}
+			transfer-encoding {
+			    set state(transfer) \
+				    [string trim [string tolower $value]]
+			}
+			proxy-connection -
+			connection {
+			    set state(connection) \
+				    [string trim [string tolower $value]]
+			}
 		    }
+		    lappend state(meta) $key [string trim $value]
 		}
-		lappend state(meta) $key [string trim $value]
 	    }
-	}
-    } else {
-	# Now reading body
-	if {[catch {
-	    if {[info exists state(-handler)]} {
-		set n [eval $state(-handler) [list $sock $token]]
-	    } elseif {[info exists state(transfer_final)]} {
-		set line [getTextLine $sock]
-		set n [string length $line]
-		if {$n > 0} {
-		    Log "found $n bytes following final chunk"
-		    append state(transfer_final) $line
-		} else {
-		    Log "final chunk part"
-		    Eof $token
-		}
-	    } elseif {
-		[info exists state(transfer)]
-		&& $state(transfer) eq "chunked"
-	    } {
-		set size 0
-		set chunk [getTextLine $sock]
-		set n [string length $chunk]
-		if {[string trim $chunk] ne ""} {
-		    scan $chunk %x size
-		    if {$size != 0} {
-			set bl [fconfigure $sock -blocking]
-			fconfigure $sock -blocking 1
-			set chunk [read $sock $size]
-			fconfigure $sock -blocking $bl
-			set n [string length $chunk]
-			if {$n >= 0} {
-			    append state(body) $chunk
+	} else {
+	    # Now reading body
+	    ##Log body - token $token
+	    if {[catch {
+		if {[info exists state(-handler)]} {
+		    set n [eval $state(-handler) [list $sock $token]]
+		    ##Log handler $n - token $token
+		    # N.B. the protocol has been set to 1.0 because the -handler
+		    # logic is not expected to handle chunked encoding.
+		    # FIXME Allow -handler with 1.1 on dechunked stacked chan.
+		    if {$state(totalsize) == 0} {
+			# We know the transfer is complete only when the server
+			# closes the connection - i.e. eof is not an error.
+			set state(state) complete
+		    }
+		    if {![string is integer -strict $n]} {
+			if 1 {
+			    # Do not tolerate bad -handler - fail with error
+			    # status.
+			    set msg {the -handler command for http::geturl must\
+				    return an integer (the number of bytes\
+				    read)}
+			    Log ^X$tk end of response (handler error) -\
+				    token $token
+			    Eot $token $msg
+			} else {
+			    # Tolerate the bad -handler, and continue.  The
+			    # penalty:
+			    # (a) Because the handler returns nonsense, we know
+			    #     the transfer is complete only when the server
+			    #     closes the connection - i.e. eof is not an
+			    #     error.
+			    # (b) http::size will not be accurate.
+			    # (c) The transaction is already downgraded to 1.0
+			    #     to avoid chunked transfer encoding.  It MUST
+			    #     also be forced to "Connection: close" or the
+			    #     HTTP/1.0 equivalent; or it MUST fail (as
+			    #     above) if the server sends
+			    #     "Connection: keep-alive" or the HTTP/1.0
+			    #     equivalent.
+			    set n 0
+			    set state(state) complete
 			}
-			if {$size != [string length $chunk]} {
-			    Log "WARNING: mis-sized chunk:\
-				was [string length $chunk], should be $size"
+		    }
+		} elseif {[info exists state(transfer_final)]} {
+		    # This code forgives EOF in place of the final CRLF.
+		    set line [getTextLine $sock]
+		    set n [string length $line]
+		    set state(state) complete
+		    if {$n > 0} {
+			# - HTTP trailers (late response headers) are permitted
+			#   by Chunked Transfer-Encoding, and can be safely
+			#   ignored.
+			# - Do not count these bytes in the total received for
+			#   the response body.
+			Log "trailer of $n bytes after final chunk -\
+				token $token"
+			append state(transfer_final) $line
+			set n 0
+		    } else {
+			Log ^F$tk end of response body (chunked) - token $token
+			Log "final chunk part - token $token"
+			Eot $token
+		    }
+		} elseif {    [info exists state(transfer)]
+			   && ($state(transfer) eq "chunked")
+		} {
+		    ##Log chunked - token $token
+		    set size 0
+		    set hexLenChunk [getTextLine $sock]
+		    #set ntl [string length $hexLenChunk]
+		    if {[string trim $hexLenChunk] ne ""} {
+			scan $hexLenChunk %x size
+			if {$size != 0} {
+			    ##Log chunk-measure $size - token $token
+			    set chunk [BlockingRead $sock $size]
+			    set n [string length $chunk]
+			    if {$n >= 0} {
+				append state(body) $chunk
+				incr state(log_size) [string length $chunk]
+				##Log chunk $n cumul $state(log_size) -\
+					token $token
+			    }
+			    if {$size != [string length $chunk]} {
+				Log "WARNING: mis-sized chunk:\
+				    was [string length $chunk], should be\
+				    $size - token $token"
+				set n 0
+				set state(connection) close
+				Log ^X$tk end of response (chunk error) \
+					- token $token
+				set msg {error in chunked encoding - fetch\
+					terminated}
+				Eot $token $msg
+			    }
+			    # CRLF that follows chunk.
+			    # If eof, this is handled at the end of this proc.
+			    getTextLine $sock
+			} else {
+			    set n 0
+			    set state(transfer_final) {}
 			}
-			getTextLine $sock
 		    } else {
-			set state(transfer_final) {}
+			# Line expected to hold chunk length is empty, or eof.
+			##Log bad-chunk-measure - token $token
+			set n 0
+			set state(connection) close
+			Log ^X$tk end of response (chunk error) - token $token
+			Eot $token {error in chunked encoding -\
+				fetch terminated}
+		    }
+		} else {
+		    ##Log unchunked - token $token
+		    if {$state(totalsize) == 0} {
+			# We know the transfer is complete only when the server
+			# closes the connection.
+			set state(state) complete
+			set reqSize $state(-blocksize)
+		    } else {
+			# Ask for the whole of the unserved response-body.
+			# This works around a problem with a tls::socket - for
+			# https in keep-alive mode, and a request for
+			# $state(-blocksize) bytes, the last part of the
+			# resource does not get read until the server times out.
+			set reqSize [expr {  $state(totalsize)
+					   - $state(currentsize)}]
+
+			# The workaround fails if reqSize is
+			# capped at $state(-blocksize).
+			# set reqSize [expr {min($reqSize, $state(-blocksize))}]
+		    }
+		    set c $state(currentsize)
+		    set t $state(totalsize)
+		    ##Log non-chunk currentsize $c of totalsize $t -\
+			    token $token
+		    set block [read $sock $reqSize]
+		    set n [string length $block]
+		    if {$n >= 0} {
+			append state(body) $block
+			##Log non-chunk [string length $state(body)] -\
+				token $token
 		    }
 		}
+		# This calculation uses n from the -handler, chunked, or
+		# unchunked case as appropriate.
+		if {[info exists state]} {
+		    if {$n >= 0} {
+			incr state(currentsize) $n
+			set c $state(currentsize)
+			set t $state(totalsize)
+			##Log another $n currentsize $c totalsize $t -\
+				token $token
+		    }
+		    # If Content-Length - check for end of data.
+		    if {
+			   ($state(totalsize) > 0)
+			&& ($state(currentsize) >= $state(totalsize))
+		    } {
+			Log ^F$tk end of response body (unchunked) -\
+				token $token
+			set state(state) complete
+			Eot $token
+		    }
+		}
+	    } err]} {
+		Log ^X$tk end of response (error ${err}) - token $token
+		Finish $token $err
+		return
 	    } else {
-		#Log "read non-chunk $state(currentsize) of $state(totalsize)"
-		set block [read $sock $state(-blocksize)]
-		set n [string length $block]
-		if {$n >= 0} {
-		    append state(body) $block
+		if {[info exists state(-progress)]} {
+		    eval $state(-progress) \
+			[list $token $state(totalsize) $state(currentsize)]
 		}
 	    }
-	    if {[info exists state]} {
-		if {$n >= 0} {
-		    incr state(currentsize) $n
-		}
-		# If Content-Length - check for end of data.
-		if {
-		    ($state(totalsize) > 0)
-		    && ($state(currentsize) >= $state(totalsize))
-		} {
-		    Eof $token
+	}
+
+	# catch as an Eot above may have closed the socket already
+	# $state(state) may be connecting, header, body, or complete
+	if {![set cc [catch {eof $sock} eof]] && $eof} {
+	    ##Log eof - token $token
+	    if {[info exists $token]} {
+		set state(connection) close
+		if {$state(state) eq "complete"} {
+		    # This includes all cases in which the transaction
+		    # can be completed by eof.
+		    # The value "complete" is set only in http::Event, and it is
+		    # used only in the test above.
+		    Log ^F$tk end of response body (unchunked, eof) -\
+			    token $token
+		    Eot $token
+		} else {
+		    # Premature eof.
+		    Log ^X$tk end of response (unexpected eof) - token $token
+		    Eot $token eof
 		}
+	    } else {
+		# open connection closed on a token that has been cleaned up.
+		Log ^X$tk end of response (token error) - token $token
+		CloseSocket $sock
 	    }
-	} err]} {
-	    return [Finish $token $err]
-	} else {
-	    if {[info exists state(-progress)]} {
-		eval $state(-progress) \
-		    [list $token $state(totalsize) $state(currentsize)]
-	    }
+	} elseif {$cc} {
+	    return
 	}
     }
+}
 
-    # catch as an Eof above may have closed the socket already
-    if {![catch {eof $sock} eof] && $eof} {
-	if {[info exists $token]} {
-	    set state(connection) close
-	    Eof $token
-	} else {
-	    # open connection closed on a token that has been cleaned up.
-	    CloseSocket $sock
-	}
-	return
+# http::TestForReplay
+#
+#	Command called if eof is discovered when a socket is first used for a
+#	new transaction.  Typically this occurs if a persistent socket is used
+#	after a period of idleness and the server has half-closed the socket.
+#
+# token  - the connection token returned by http::geturl
+# doing  - "read" or "write"
+# err    - error message, if any
+# caller - code to identify the caller - used only in logging
+#
+# Return Value: boolean, true iff the command calls http::ReplayIfDead.
+
+proc http::TestForReplay {token doing err caller} {
+    variable http
+    variable $token
+    upvar 0 $token state
+    set tk [namespace tail $token]
+    if {$doing eq "read"} {
+	set code Q
+	set action response
+	set ing reading
+    } else {
+	set code P
+	set action request
+	set ing writing
+    }
+
+    if {$err eq {}} {
+	set err "detect eof when $ing (server timed out?)"
+    }
+
+    if {$state(method) eq "POST" && !$http(-repost)} {
+	# No Replay.
+	# The present transaction will end when Finish is called.
+	# That call to Finish will abort any other transactions
+	# currently in the write queue.
+	# For calls from http::Event this occurs when execution
+	# reaches the code block at the end of that proc.
+	set msg {no retry for POST with http::config -repost 0}
+	Log reusing socket failed "($caller)" - $msg - token $token
+	Log error - $err - token $token
+	Log ^X$tk end of $action (error) - token $token
+	return 0
+    } else {
+	# Replay.
+	set msg {try a new socket}
+	Log reusing socket failed "($caller)" - $msg - token $token
+	Log error - $err - token $token
+	Log ^$code$tk Any unfinished (incl this one) failed - token $token
+	ReplayIfDead $token $doing
+	return 1
     }
 }
 
@@ -1228,7 +2992,10 @@ proc http::IsBinaryContentType {type} {
 
 # http::getTextLine --
 #
-#	Get one line with the stream in blocking crlf mode
+#	Get one line with the stream in crlf mode.
+#	Used if Transfer-Encoding is chunked.
+#	Empty line is not distinguished from eof.  The caller must
+#	be able to handle this.
 #
 # Arguments
 #	sock	The socket receiving input.
@@ -1238,13 +3005,55 @@ proc http::IsBinaryContentType {type} {
 
 proc http::getTextLine {sock} {
     set tr [fconfigure $sock -translation]
-    set bl [fconfigure $sock -blocking]
-    fconfigure $sock -translation crlf -blocking 1
-    set r [gets $sock]
-    fconfigure $sock -translation $tr -blocking $bl
+    lassign $tr trRead trWrite
+    fconfigure $sock -translation [list crlf $trWrite]
+    set r [BlockingGets $sock]
+    fconfigure $sock -translation $tr
     return $r
 }
 
+# http::BlockingRead
+#
+#	Replacement for a blocking read.
+#	The caller must be a coroutine.
+
+proc http::BlockingRead {sock size} {
+    if {$size < 1} {
+	return
+    }
+    set result {}
+    while 1 {
+	set need [expr {$size - [string length $result]}]
+	set block [read $sock $need]
+	set eof [eof $sock]
+	append result $block
+	if {[string length $result] >= $size || $eof} {
+	    return $result
+	} else {
+	    yield
+	}
+    }
+}
+
+# http::BlockingGets
+#
+#	Replacement for a blocking gets.
+#	The caller must be a coroutine.
+#	Empty line is not distinguished from eof.  The caller must
+#	be able to handle this.
+
+proc http::BlockingGets {sock} {
+    while 1 {
+	set count [gets $sock line]
+	set eof [eof $sock]
+	if {$count > -1 || $eof} {
+	    return $line
+	} else {
+	    yield
+	}
+    }
+}
+
 # http::CopyStart
 #
 #	Error handling wrapper around fcopy
@@ -1270,6 +3079,10 @@ proc http::CopyStart {sock token {initial 1}} {
 	    }
 	}
 	if {[catch {
+	    # FIXME Keep-Alive on https tls::socket with unchunked transfer
+	    # hangs until the server times out. A workaround is possible, as for
+	    # the case without -channel, but it does not use the neat "fcopy"
+	    # solution.
 	    fcopy $sock $state(-channel) -size $state(-blocksize) -command \
 		[list http::CopyDone $token]
 	} err]} {
@@ -1293,7 +3106,7 @@ proc http::CopyChunk {token chunk} {
 		      $token $state(totalsize) $state(currentsize)]
 	}
     } else {
-	Log "CopyChunk Finish $token"
+	Log "CopyChunk Finish - token $token"
 	if {[info exists state(zlib)]} {
 	    set excess ""
 	    foreach stream $state(zlib) {
@@ -1303,7 +3116,7 @@ proc http::CopyChunk {token chunk} {
 	    foreach stream $state(zlib) { $stream close }
 	    unset state(zlib)
 	}
-	Eof $token ;# FIX ME: pipelining.
+	Eot $token ;# FIX ME: pipelining.
     }
 }
 
@@ -1327,33 +3140,53 @@ proc http::CopyDone {token count {error {}}} {
 	eval $state(-progress) \
 	    [list $token $state(totalsize) $state(currentsize)]
     }
-    # At this point the token may have been reset
+    # At this point the token may have been reset.
     if {[string length $error]} {
 	Finish $token $error
     } elseif {[catch {eof $sock} iseof] || $iseof} {
-	Eof $token
+	Eot $token
     } else {
 	CopyStart $sock $token 0
     }
 }
 
-# http::Eof
+# http::Eot
 #
-#	Handle eof on the socket
+#	Called when either:
+#	a. An eof condition is detected on the socket.
+#	b. The client decides that the response is complete.
+#	c. The client detects an inconsistency and aborts the transaction.
+#
+#	Does:
+#	1. Set state(status)
+#	2. Reverse any Content-Encoding
+#	3. Convert charset encoding and line ends if necessary
+#	4. Call http::Finish
 #
 # Arguments
 #	token	The token returned from http::geturl
+#	force	(previously) optional, has no effect
+#	reason	- "eof" means premature EOF (not EOF as the natural end of
+#		  the response)
+#		- "" means completion of response, with or without EOF
+#		- anything else describes an error confition other than
+#		  premature EOF.
 #
 # Side Effects
 #	Clean up the socket
 
-proc http::Eof {token {force 0}} {
+proc http::Eot {token {reason {}}} {
     variable $token
     upvar 0 $token state
-    if {$state(state) eq "header"} {
-	# Premature eof
+    if {$reason eq "eof"} {
+	# Premature eof.
 	set state(status) eof
+	set reason {}
+    } elseif {$reason ne ""} {
+	# Abort the transaction.
+	set state(status) $reason
     } else {
+	# The response is complete.
 	set state(status) ok
     }
 
@@ -1363,14 +3196,15 @@ proc http::Eof {token {force 0}} {
 		set state(body) [zlib $coding $state(body)]
 	    }
 	} err]} {
-	    Log "error doing decompression: $err"
-	    return [Finish $token $err]
+	    Log "error doing decompression for token $token: $err"
+	    Finish $token $err
+	    return
 	}
 
 	if {!$state(binary)} {
 	    # If we are getting text, set the incoming channel's encoding
-	    # correctly.  iso8859-1 is the RFC default, but this could be any IANA
-	    # charset.  However, we only know how to convert what we have
+	    # correctly.  iso8859-1 is the RFC default, but this could be any
+	    # IANA charset.  However, we only know how to convert what we have
 	    # encodings for.
 
 	    set enc [CharsetToEncoding $state(charset)]
@@ -1382,7 +3216,7 @@ proc http::Eof {token {force 0}} {
 	    set state(body) [string map {\r\n \n \r \n} $state(body)]
 	}
     }
-    Finish $token
+    Finish $token $reason
 }
 
 # http::wait --
@@ -1393,7 +3227,7 @@ proc http::Eof {token {force 0}} {
 #	token	Connection token.
 #
 # Results:
-#        The status after the wait.
+#	The status after the wait.
 
 proc http::wait {token} {
     variable $token
@@ -1420,6 +3254,12 @@ proc http::wait {token} {
 #	TODO
 
 proc http::formatQuery {args} {
+    if {[llength $args] % 2} {
+        return \
+            -code error \
+            -errorcode [list HTTP BADARGCNT $args] \
+            {Incorrect number of arguments, must be an even number.}
+    }
     set result ""
     set sep ""
     foreach i $args {
@@ -1464,6 +3304,7 @@ proc http::mapReply {string} {
     }
     return $converted
 }
+interp alias {} http::quoteString {} http::mapReply
 
 # http::ProxyRequired --
 #	Default proxy filter.
@@ -1546,37 +3387,39 @@ proc http::ContentEncoding {token} {
     return $r
 }
 
+proc http::ReceiveChunked {chan command} {
+    set data ""
+    set size -1
+    yield
+    while {1} {
+	chan configure $chan -translation {crlf binary}
+	while {[gets $chan line] < 1} { yield }
+	chan configure $chan -translation {binary binary}
+	if {[scan $line %x size] != 1} {
+	    return -code error "invalid size: \"$line\""
+	}
+	set chunk ""
+	while {$size && ![chan eof $chan]} {
+	    set part [chan read $chan $size]
+	    incr size -[string length $part]
+	    append chunk $part
+	}
+	if {[catch {
+	    uplevel #0 [linsert $command end $chunk]
+	}]} {
+	    http::Log "Error in callback: $::errorInfo"
+	}
+	if {[string length $chunk] == 0} {
+	    # channel might have been closed in the callback
+	    catch {chan event $chan readable {}}
+	    return
+	}
+    }
+}
+
 proc http::make-transformation-chunked {chan command} {
-    set lambda {{chan command} {
-        set data ""
-        set size -1
-        yield
-        while {1} {
-            chan configure $chan -translation {crlf binary}
-            while {[gets $chan line] < 1} { yield }
-            chan configure $chan -translation {binary binary}
-            if {[scan $line %x size] != 1} { return -code error "invalid size: \"$line\"" }
-            set chunk ""
-            while {$size && ![chan eof $chan]} {
-                set part [chan read $chan $size]
-                incr size -[string length $part]
-                append chunk $part
-            }
-            if {[catch {
-		uplevel #0 [linsert $command end $chunk]
-	    }]} {
-		http::Log "Error in callback: $::errorInfo"
-	    }
-            if {[string length $chunk] == 0} {
-		# channel might have been closed in the callback
-                catch {chan event $chan readable {}}
-                return
-            }
-        }
-    }}
-    coroutine dechunk$chan ::apply $lambda $chan $command
-    chan event $chan readable [namespace origin dechunk$chan]
-    return
+    coroutine [namespace current]::dechunk$chan ::http::ReceiveChunked $chan $command
+    chan event $chan readable [namespace current]::dechunk$chan
 }
 
 # Local variables:
diff --git a/tcl8.6/library/http/pkgIndex.tcl b/tcl8.6/library/http/pkgIndex.tcl
index d3fc7af..4f74635 100644
--- a/tcl8.6/library/http/pkgIndex.tcl
+++ b/tcl8.6/library/http/pkgIndex.tcl
@@ -1,2 +1,2 @@
 if {![package vsatisfies [package provide Tcl] 8.6-]} {return}
-package ifneeded http 2.8.12 [list tclPkgSetup $dir http 2.8.12 {{http.tcl source {::http::config ::http::formatQuery ::http::geturl ::http::reset ::http::wait ::http::register ::http::unregister ::http::mapReply}}}]
+package ifneeded http 2.9.0 [list tclPkgSetup $dir http 2.9.0 {{http.tcl source {::http::config ::http::formatQuery ::http::geturl ::http::reset ::http::wait ::http::register ::http::unregister ::http::mapReply}}}]