tag: invalidate tag cache immediately after adding new tag (issue3210)

New tags were written to .hgtags / .hglocaltags without updating or
invalidating the localrepo cache.

Before afd459933d5f a lock was acquired soon after the new tags had been
written, and that invalidated the cache so the new tags for example could be
seen in pretxncommit hooks. With afd459933d5f the lock had already been
acquired at this point and the missing cache invalidation was exposed.

The tag caches will now explicitly and immediately be invalidated when new tags
are added.

mercurial/localrepo.py

@@ -326,6 +326,8 b' class localrepository(repo.repository):'
 
         fp.close()
 
+        self.invalidatecaches()
+
         if '.hgtags' not in self.dirstate:
             self[None].add(['.hgtags'])
 

tests/test-hook.t

@@ -353,6 +353,9 b' preoutgoing hook can prevent outgoing ch'
   > def verbosehook(ui, **args):
   >     ui.note('verbose output from hook\n')
   > 
+  > def printtags(ui, repo, **args):
+  >     print repo.tags().keys()
+  > 
   > class container:
   >     unreachable = 1
   > EOF
@@ -569,3 +572,10 b' Ensure hooks can be prioritized'
   calling hook pre-identify.c: hooktests.verbosehook
   verbose output from hook
   cb9a9f314b8b
+
+new tags must be visible in pretxncommit (issue3210)
+
+  $ echo 'pretxncommit.printtags = python:hooktests.printtags' >> .hg/hgrc
+  $ hg tag -f foo
+  ['a', 'foo', 'tip']
+