lock: show more detail for new-style locks in lock waiting message (issue4752)

Improve the lock waiting warning message by explicitly saying that a host and
process are holding the lock. This nudges confused new users in the direction
of investigating the other process instead of removing the lock.

mercurial/localrepo.py

@@ -1290,6 +1290,13 b' class localrepository(object):'
         except error.LockHeld as inst:
             if not wait:
                 raise
+            # show more details for new-style locks
+            if ':' in inst.locker:
+                host, pid = inst.locker.split(":", 1)
+                self.ui.warn(
+                    _("waiting for lock on %s held by process %r "
+                      "on host %r\n") % (desc, pid, host))
+            else:
             self.ui.warn(_("waiting for lock on %s held by %r\n") %
                          (desc, inst.locker))
             # default to 600 seconds timeout

tests/test-lock-badness.t

@@ -60,7 +60,7 b' One process waiting for another'
   > > preup 2>&1
   $ wait
   $ cat preup
-  waiting for lock on working directory of b held by '*:*' (glob)
+  waiting for lock on working directory of b held by process '*' on host '*' (glob)
   got lock after * seconds (glob)
   $ cat stdout
   adding b