tests/test-http-proxy.t

inno: replace add_path.exe with a Pascal script

While attempting to build the Inno installer, I was unable to
find a copy of add_path.exe from the source site previously
listed in the docs.

Some quick Googling revealed that achieving this functionality
in native Pascal scripts seems to be preferred these days.

This commit vendors "Modify Path" (fetched from
https://www.legroom.net/software/modpath) and plugs it into
our Inno config file per its instructions.

The existing Inno installer appears to only modify PATH for
the current user (as opposed to at the system level). I've
maintained this behavior with Modify Path. Although it would
be trivial to change or add checkboxes to control the behavior.
I'll leave this as a follow-up.

Differential Revision: https://phab.mercurial-scm.org/D6060

#require serve

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Ama -d '1123456789 0'
  adding a
  $ hg serve --config server.uncompressed=True -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ cd ..
  $ tinyproxy.py $HGPORT1 localhost 2>proxy.log >/dev/null </dev/null &
  $ while [ ! -f proxy.pid ]; do sleep 0; done
  $ cat proxy.pid >> $DAEMON_PIDS

url for proxy, stream

  $ http_proxy=http://localhost:$HGPORT1/ hg --config http_proxy.always=True clone --stream http://localhost:$HGPORT/ b
  streaming all changes
  6 files to transfer, 412 bytes of data (reporevlogstore !)
  4 files to transfer, 330 bytes of data (reposimplestore !)
  transferred * bytes in * seconds (*/sec) (glob)
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd b
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files
  $ cd ..

url for proxy, pull

  $ http_proxy=http://localhost:$HGPORT1/ hg --config http_proxy.always=True clone http://localhost:$HGPORT/ b-pull
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 83180e7845de
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd b-pull
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files
  $ cd ..

host:port for proxy

  $ http_proxy=localhost:$HGPORT1 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ c
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 83180e7845de
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

proxy url with user name and password

  $ http_proxy=http://user:passwd@localhost:$HGPORT1 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ d
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 83180e7845de
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

url with user name and password

  $ http_proxy=http://user:passwd@localhost:$HGPORT1 hg clone --config http_proxy.always=True http://user:passwd@localhost:$HGPORT/ e
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 83180e7845de
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

bad host:port for proxy ("Protocol not supported" can happen on
misconfigured hosts)

  $ http_proxy=localhost:$HGPORT2 hg clone --config http_proxy.always=True http://localhost:$HGPORT/ f
  abort: error: (Connection refused|Protocol not supported|.* actively refused it|\$EADDRNOTAVAIL\$|No route to host) (re)
  [255]

do not use the proxy if it is in the no list

  $ http_proxy=localhost:$HGPORT1 hg clone --config http_proxy.no=localhost http://localhost:$HGPORT/ g
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 83180e7845de
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat proxy.log
  * - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=0&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&stream=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  * - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  * - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  * - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  * - - [*] "GET http://localhost:$HGPORT/?cmd=capabilities HTTP/1.1" - - (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=batch HTTP/1.1" - - x-hgarg-1:cmds=heads+%3Bknown+nodes%3D x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)
  $LOCALIP - - [$LOGDATE$] "GET http://localhost:$HGPORT/?cmd=getbundle HTTP/1.1" - - x-hgarg-1:bookmarks=1&$USUAL_BUNDLE_CAPS$&cg=1&common=0000000000000000000000000000000000000000&heads=83180e7845de420a1bb46896fd5fe05294f8d629&listkeys=bookmarks&phases=1 x-hgproto-1:0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull (glob)