subrepo: only do clean update when overwrite is set (issue3276)

Files in a subrepo were overwritten on update. But this should only happen on a
clean update (example: -C is specified).
Use the overwrite parameter introduced for svn subrepos in c19b9282d3a7 to
decide whether to merge changes (as update) or remove them (as clean).

The new function hg.updaterepo is intruduced to keep all update calls in hg.

test-subrepo.t is extended to test if an untracked file is overwritten
(issue3276). (Update -C is already tested in many places.)
The first two chunks are debugging output which has changed. (Because overwrite
is not always true anymore for subrepos)
All other tests still pass without any change.

mercurial/hg.py

@@ -459,9 +459,17 b' def _showstats(repo, stats):'
     repo.ui.status(_("%d files updated, %d files merged, "
                      "%d files removed, %d files unresolved\n") % stats)
 
+def updaterepo(repo, node, overwrite):
+    """Update the working directory to node.
+
+    When overwrite is set, changes are clobbered, merged else
+
+    returns stats (see pydoc mercurial.merge.applyupdates)"""
+    return mergemod.update(repo, node, False, overwrite, None)
+
 def update(repo, node):
     """update the working directory to node, merging linear changes"""
-    stats = mergemod.update(repo, node, False, False, None)
+    stats = updaterepo(repo, node, False)
     _showstats(repo, stats)
     if stats[3]:
         repo.ui.status(_("use 'hg resolve' to retry unresolved file merges\n"))
@@ -472,7 +480,7 b' def update(repo, node):'
 
 def clean(repo, node, show_stats=True):
     """forcibly switch the working directory to node, clobbering changes"""
-    stats = mergemod.update(repo, node, False, True, None)
+    stats = updaterepo(repo, node, True)
     if show_stats:
         _showstats(repo, stats)
     return stats[3] > 0

mercurial/subrepo.py

@@ -523,7 +523,7 b' class hgsubrepo(abstractsubrepo):'
         self._get(state)
         source, revision, kind = state
         self._repo.ui.debug("getting subrepo %s\n" % self._path)
-        hg.clean(self._repo, revision, False)
+        hg.updaterepo(self._repo, revision, overwrite)
 
     def merge(self, state):
         self._get(state)

tests/test-subrepo.t

@@ -210,9 +210,10 b' merge tests'
   subrepo merge f0d2028bf86d+ 1831e14459c4 1f14a2e2d3ec
     subrepo t: other changed, get t:6747d179aa9a688023c4b0cad32e4c92bb7f34ad:hg
   getting subrepo t
+    searching for copies back to rev 1
   resolving manifests
-   overwrite: True, partial: False
-   ancestor: 60ca1237c194+, local: 60ca1237c194+, remote: 6747d179aa9a
+   overwrite: False, partial: False
+   ancestor: 60ca1237c194, local: 60ca1237c194+, remote: 6747d179aa9a
    t: remote is newer -> g
   updating: t 1/1 files (100.00%)
   getting t
@@ -580,16 +581,37 b' Issue1977: multirepo push should fail if'
   $ hg -q -R repo2/s push
   $ hg -R repo2/s up -C 0
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
-  $ echo 2 > repo2/s/a
-  $ hg -R repo2/s ci -m3
+  $ echo 2 > repo2/s/b
+  $ hg -R repo2/s ci -m3 -A
+  adding b
   created new head
   $ hg -R repo2 ci -m3
   $ hg -q -R repo2 push
-  abort: push creates new remote head 9d66565e64e1!
+  abort: push creates new remote head cc505f09a8b2!
   (did you forget to merge? use push -f to force)
   [255]
   $ hg -R repo update
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+
+test if untracked file is not overwritten
+
+  $ echo issue3276_ok > repo/s/b
+  $ hg -R repo2 push -f -q
+  $ hg -R repo update
+  b: untracked file differs
+  abort: untracked files in working directory differ from files in requested revision
+  [255]
+
+  $ cat repo/s/b
+  issue3276_ok
+  $ rm repo/s/b
+  $ hg -R repo revert --all
+  reverting repo/.hgsubstate
+  reverting subrepo s
+  $ hg -R repo update
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cat repo/s/b
+  2
   $ rm -rf repo2 repo