narrow_widen_acl: enforce narrowacl in narrow_widen (SEC)

Reviewer note: this was sent by the author as a simple bugfix, but can be
considered a security patch, since it allows users to access things outside
of the ACL, hence the (SEC) prefix.

However, this affects the `narrow` extention which is still marked as
experimental and has relatively few users aside from large companies with
their own security layers on top from what we can gather.
We feel (Alphare: or at least, I feel) like pinging the packaging list is
enough in this case.

hgext/narrow/narrowwirepeer.py

@@ -10,6 +10,7 b' from __future__ import absolute_import'
 from mercurial import (
     bundle2,
     error,
+    exchange,
     extensions,
     hg,
     narrowspec,
@@ -86,6 +87,11 b' def narrow_widen('
         newincludes = splitpaths(newincludes)
         oldexcludes = splitpaths(oldexcludes)
         newexcludes = splitpaths(newexcludes)
+
+        # enforce narrow acl if set
+        if repo.ui.has_section(exchange._NARROWACL_SECTION):
+            exchange.applynarrowacl(repo, {'includepats': newincludes})
+
         # validate the patterns
         narrowspec.validatepatterns(set(oldincludes))
         narrowspec.validatepatterns(set(newincludes))

tests/test-narrow-acl.t

@@ -41,3 +41,39 b' NarrowHG should track f1 and f2'
   $ hg -R narrowclone1 tracked
   I path:f1
   I path:f2
+
+Narrow should not be able to widen to include f3
+  $ hg -R narrowclone1 tracked --addinclude f3
+  comparing with http://localhost:$HGPORT1/
+  searching for changes
+  abort: The following includes are not accessible for test: ['path:f3']
+  [255]
+  $ ls -A -1 narrowclone1 | sort
+  .hg
+  f1
+  f2
+  $ hg -R narrowclone1 tracked
+  I path:f1
+  I path:f2
+
+Narrow should allow widen to include f2
+  $ hg -R narrowclone1 tracked --removeinclude f2 > /dev/null
+  $ hg -R narrowclone1 tracked
+  I path:f1
+  $ ls -A -1 narrowclone1 | sort
+  .hg
+  f1
+  $ hg -R narrowclone1 tracked --addinclude f2
+  comparing with http://localhost:$HGPORT1/
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 0 changesets with 1 changes to 1 files
+  $ hg -R narrowclone1 tracked
+  I path:f1
+  I path:f2
+  $ ls -A -1 narrowclone1 | sort
+  .hg
+  f1
+  f2