merge: do the trivial resolution after updating sparse checkout stable

merge: do the trivial resolution after updating sparse checkout

In merge, we do trivial resolution for files which were deleted on one side and
changed on other. When sparse extension in involved that file might not be
present in wdir and trivial resolution can lead to file not found error. This
patch make sure we updates the sparse checkout before doing the trivial
resolution.

This fixes the test failure demonstrated in previous patch.

Differential Revision: https://phab.mercurial-scm.org/D3984

--- a/mercurial/merge.py	Fri Jul 27 14:53:28 2018 +0300
+++ b/mercurial/merge.py	Fri Jul 27 14:56:10 2018 +0300
@@ -1424,14 +1424,13 @@
                 del actions[f]
         repo.ui.note(_('end of auction\n\n'))
 
-    _resolvetrivial(repo, wctx, mctx, ancestors[0], actions)
-
     if wctx.rev() is None:
         fractions = _forgetremoved(wctx, mctx, branchmerge)
         actions.update(fractions)
 
     prunedactions = sparse.filterupdatesactions(repo, wctx, mctx, branchmerge,
                                                 actions)
+    _resolvetrivial(repo, wctx, mctx, ancestors[0], actions)
 
     return prunedactions, diverge, renamedelete
 

--- a/tests/test-sparse-merges.t	Fri Jul 27 14:53:28 2018 +0300
+++ b/tests/test-sparse-merges.t	Fri Jul 27 14:56:10 2018 +0300
@@ -112,5 +112,9 @@
   a
 
   $ hg merge
-  abort: $ENOENT$: '$TESTTMP/ytest/d'
-  [255]
+  temporarily included 1 file(s) in the sparse checkout for merging
+  local [working copy] changed d which other [merge rev] deleted
+  use (c)hanged version, (d)elete, or leave (u)nresolved? u
+  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
+  [1]