hg: introduce "wirepeersetupfuncs" to setup wire peer by extensions (issue4109)

Since changeset 6f72e7d28b35, "reposetup()" of each extensions is
invoked only on repositories enabling corresponded extensions.

This causes that largefiles specific interactions between the
repository enabling largefiles locally and remote (wire) peer fail,
because there is no way to know whether largefiles is enabled on the
remote repository behind the wire peer, and largefiles specific
"wireproto functions" are not given to any wire peers.

To avoid this problem, largefiles should be enabled in wider scope
than each repositories (e.g. user-wide "${HOME}/.hgrc").

This patch introduces "wirepeersetupfuncs" to setup wire peer by
extensions already enabled. Functions registered into
"wirepeersetupfuncs" are invoked for all wire peers.

This patch uses plain list instead of "util.hooks" for
"wirepeersetupfuncs", because the former allows to control order of
function invocation by order of extension enabling: it may be useful
for workaround of problems with combination of enabled extensions

hgext/largefiles/__init__.py

@@ -105,9 +105,10 b' explicitly do so with the --large flag p'
 command.
 '''
 
-from mercurial import commands, localrepo
+from mercurial import commands, hg, localrepo
 
 import lfcommands
+import proto
 import reposetup
 import uisetup as uisetupmod
 
@@ -121,6 +122,7 b' def featuresetup(ui, supported):'
 
 def uisetup(ui):
     localrepo.localrepository.featuresetupfuncs.add(featuresetup)
+    hg.wirepeersetupfuncs.append(proto.wirereposetup)
     uisetupmod.uisetup(ui)
 
 commands.norepo += " lfconvert"

hgext/largefiles/reposetup.py

@@ -16,14 +16,13 b' from mercurial.i18n import _'
 from mercurial import localrepo
 
 import lfcommands
-import proto
 import lfutil
 
 def reposetup(ui, repo):
-    # wire repositories should be given new wireproto functions but not the
-    # other largefiles modifications
+    # wire repositories should be given new wireproto functions
+    # by "proto.wirereposetup()" via "hg.wirepeersetupfuncs"
     if not repo.local():
-        return proto.wirereposetup(ui, repo)
+        return
 
     class lfilesrepo(repo.__class__):
         lfstatus = False

mercurial/hg.py

@@ -98,6 +98,9 b' def openpath(ui, path):'
     else:
         return url.open(ui, path)
 
+# a list of (ui, repo) functions called for wire peer initialization
+wirepeersetupfuncs = []
+
 def _peerorrepo(ui, path, create=False):
     """return a repository object for the specified path"""
     obj = _peerlookup(path).instance(ui, path, create)
@@ -106,6 +109,9 b' def _peerorrepo(ui, path, create=False):'
         hook = getattr(module, 'reposetup', None)
         if hook:
             hook(ui, obj)
+    if not obj.local():
+        for f in wirepeersetupfuncs:
+            f(ui, obj)
     return obj
 
 def repository(ui, path='', create=False):

tests/test-largefiles.t

@@ -2285,4 +2285,30 b' enabling largefiles extension.'
   $ test -d clone-pull-dst
   [1]
 
+#if serve
+
+Test largefiles specific peer setup, when largefiles is enabled
+locally (issue4109)
+
+  $ hg showconfig extensions | grep largefiles
+  extensions.largefiles=!
+  $ mkdir -p $TESTTMP/individualenabling/usercache
+
+  $ hg serve -R enabledlocally -d -p $HGPORT --pid-file hg.pid
+  $ cat hg.pid >> $DAEMON_PIDS
+
+  $ hg init pull-dst
+  $ cat > pull-dst/.hg/hgrc <<EOF
+  > [extensions]
+  > # enable locally
+  > largefiles=
+  > [largefiles]
+  > # ignore system cache to force largefiles specific wire proto access
+  > usercache=$TESTTMP/individualenabling/usercache
+  > EOF
+  $ hg -R pull-dst -q pull -u http://localhost:$HGPORT
+
+  $ "$TESTDIR/killdaemons.py" $DAEMON_PIDS
+#endif
+
   $ cd ..