sparse: add local files to temporaryfiles if they exist out of sparse

sparse: add local files to temporaryfiles if they exist out of sparse

We get the f1 from args if it's merge and check that whether that exists in
sparse checkout or not. If that does not, we add that for merging.

The error comes from very low-level where we try to read data of a
working-filectx which does not exists in the working directory. It will be
extremely ugly to plug in logic to update sparse copy with new file at such a
low level.

We already have logic related to updating the checkout with required files in
calculateupdates() and let's handle this case there only. calculateupdates()
call sparse.filterupdatesactions() and the logic is added into the latter
function.

To get the exact traceback, this patch can be backed out and
test-sparse-merges.t can be run with ui.traceback=True.

Differential Revision: https://phab.mercurial-scm.org/D4341

--- a/mercurial/sparse.py	Tue Aug 21 15:09:22 2018 +0300
+++ b/mercurial/sparse.py	Tue Aug 21 16:11:17 2018 +0300
@@ -361,6 +361,11 @@
         elif file in wctx:
             prunedactions[file] = ('r', args, msg)
 
+        if branchmerge and type == mergemod.ACTION_MERGE:
+            f1, f2, fa, move, anc = args
+            if not sparsematch(f1):
+                temporaryfiles.append(f1)
+
     if len(temporaryfiles) > 0:
         repo.ui.status(_('temporarily included %d file(s) in the sparse '
                          'checkout for merging\n') % len(temporaryfiles))

--- a/tests/test-sparse-merges.t	Tue Aug 21 15:09:22 2018 +0300
+++ b/tests/test-sparse-merges.t	Tue Aug 21 16:11:17 2018 +0300
@@ -172,10 +172,13 @@
   d
 
   $ hg merge
-  abort: $ENOENT$: $TESTTMP/mvtest/a
-  [255]
+  temporarily included 1 file(s) in the sparse checkout for merging
+  merging a and amove to amove
+  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
 
   $ hg up -C 4
+  cleaned up 1 temporarily added file(s) from the sparse checkout
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
   $ hg merge

--- a/tests/test-sparse-profiles.t	Tue Aug 21 15:09:22 2018 +0300
+++ b/tests/test-sparse-profiles.t	Tue Aug 21 16:11:17 2018 +0300
@@ -119,7 +119,7 @@
 Verify conflicting merge pulls in the conflicting changes
 
   $ hg merge 1
-  temporarily included 1 file(s) in the sparse checkout for merging
+  temporarily included 2 file(s) in the sparse checkout for merging
   merging backend.sparse
   merging data.py
   warning: conflicts while merging backend.sparse! (edit, then use 'hg resolve --mark')
@@ -184,7 +184,7 @@
 
   $ hg rebase -d 2
   rebasing 1:a2b1de640a62 "edit profile"
-  temporarily included 1 file(s) in the sparse checkout for merging
+  temporarily included 2 file(s) in the sparse checkout for merging
   merging backend.sparse
   merging data.py
   warning: conflicts while merging backend.sparse! (edit, then use 'hg resolve --mark')

--- a/tests/test-sparse.t	Tue Aug 21 15:09:22 2018 +0300
+++ b/tests/test-sparse.t	Tue Aug 21 16:11:17 2018 +0300
@@ -189,7 +189,7 @@
 
   $ hg rebase -d 1 -r 2 --config extensions.rebase=
   rebasing 2:b91df4f39e75 "edit hide" (tip)
-  temporarily included 1 file(s) in the sparse checkout for merging
+  temporarily included 2 file(s) in the sparse checkout for merging
   merging hide
   warning: conflicts while merging hide! (edit, then use 'hg resolve --mark')
   unresolved conflicts (see hg resolve, then hg rebase --continue)
@@ -224,7 +224,7 @@
 
   $ hg up -q 1
   $ hg merge -r 2
-  temporarily included 1 file(s) in the sparse checkout for merging
+  temporarily included 2 file(s) in the sparse checkout for merging
   merging hide
   warning: conflicts while merging hide! (edit, then use 'hg resolve --mark')
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved