diff mercurial/merge.py @ 44687:1b8fd4af3318

mergestate: store about files resolved in favour of other

Committing a merge sometimes wrongly creates a new filenode where it can re-use
an existing one. This happens because the commit code does it's own calculation
and does not know what happened on merge.

This starts storing information in mergestate about files which were
automatically merged and the other/remote version of file was used.
We need this information at commit to pick the filenode parent for the new
commit.

This issue was found by Pierre-Yves David and idea to store the relevant parts
in mergestate is also suggested by him.

Somethings which can be further investigated are:

1) refactoring of commit logic more to depend on this information
2) maybe a more generic solution?

Differential Revision: https://phab.mercurial-scm.org/D8392

--- a/mercurial/merge.py	Thu Apr 09 15:44:21 2020 -0400
+++ b/mercurial/merge.py	Thu Apr 09 16:06:03 2020 +0530
@@ -64,6 +64,7 @@
 RECORD_OVERRIDE = b't'
 RECORD_UNSUPPORTED_MANDATORY = b'X'
 RECORD_UNSUPPORTED_ADVISORY = b'x'
+RECORD_RESOLVED_OTHER = b'R'
 
 MERGE_DRIVER_STATE_UNMARKED = b'u'
 MERGE_DRIVER_STATE_MARKED = b'm'
@@ -74,6 +75,9 @@
 MERGE_RECORD_UNRESOLVED_PATH = b'pu'
 MERGE_RECORD_RESOLVED_PATH = b'pr'
 MERGE_RECORD_DRIVER_RESOLVED = b'd'
+# represents that the file was automatically merged in favor
+# of other version. This info is used on commit.
+MERGE_RECORD_MERGED_OTHER = b'o'
 
 ACTION_FORGET = b'f'
 ACTION_REMOVE = b'r'
@@ -91,6 +95,8 @@
 ACTION_KEEP = b'k'
 ACTION_EXEC = b'e'
 ACTION_CREATED_MERGE = b'cm'
+# GET the other/remote side and store this info in mergestate
+ACTION_GET_OTHER_AND_STORE = b'gs'
 
 
 class mergestate(object):
@@ -227,6 +233,7 @@
                 RECORD_CHANGEDELETE_CONFLICT,
                 RECORD_PATH_CONFLICT,
                 RECORD_MERGE_DRIVER_MERGE,
+                RECORD_RESOLVED_OTHER,
             ):
                 bits = record.split(b'\0')
                 self._state[bits[0]] = bits[1:]
@@ -453,6 +460,10 @@
                 records.append(
                     (RECORD_PATH_CONFLICT, b'\0'.join([filename] + v))
                 )
+            elif v[0] == MERGE_RECORD_MERGED_OTHER:
+                records.append(
+                    (RECORD_RESOLVED_OTHER, b'\0'.join([filename] + v))
+                )
             elif v[1] == nullhex or v[6] == nullhex:
                 # Change/Delete or Delete/Change conflicts. These are stored in
                 # 'C' records. v[1] is the local file, and is nullhex when the
@@ -551,6 +562,10 @@
         self._state[path] = [MERGE_RECORD_UNRESOLVED_PATH, frename, forigin]
         self._dirty = True
 
+    def addmergedother(self, path):
+        self._state[path] = [MERGE_RECORD_MERGED_OTHER, nullhex, nullhex]
+        self._dirty = True
+
     def __contains__(self, dfile):
         return dfile in self._state
 
@@ -594,6 +609,8 @@
         """rerun merge process for file path `dfile`"""
         if self[dfile] in (MERGE_RECORD_RESOLVED, MERGE_RECORD_DRIVER_RESOLVED):
             return True, 0
+        if self._state[dfile][0] == MERGE_RECORD_MERGED_OTHER:
+            return True, 0
         stateentry = self._state[dfile]
         state, localkey, lfile, afile, anode, ofile, onode, flags = stateentry
         octx = self._repo[self._other]
@@ -1209,7 +1226,7 @@
     narrowed.
     """
     nooptypes = {b'k'}  # TODO: handle with nonconflicttypes
-    nonconflicttypes = set(b'a am c cm f g r e'.split())
+    nonconflicttypes = set(b'a am c cm f g gs r e'.split())
     # We mutate the items in the dict during iteration, so iterate
     # over a copy.
     for f, action in list(actions.items()):
@@ -1348,14 +1365,22 @@
                         )
                     else:
                         actions[f] = (
-                            ACTION_GET,
+                            ACTION_GET_OTHER_AND_STORE
+                            if branchmerge
+                            else ACTION_GET,
                             (fl2, False),
                             b'remote is newer',
                         )
                 elif nol and n2 == a:  # remote only changed 'x'
                     actions[f] = (ACTION_EXEC, (fl2,), b'update permissions')
                 elif nol and n1 == a:  # local only changed 'x'
-                    actions[f] = (ACTION_GET, (fl1, False), b'remote is newer')
+                    actions[f] = (
+                        ACTION_GET_OTHER_AND_STORE
+                        if branchmerge
+                        else ACTION_GET,
+                        (fl1, False),
+                        b'remote is newer',
+                    )
                 else:  # both changed something
                     actions[f] = (
                         ACTION_MERGE,
@@ -1588,6 +1613,8 @@
 
             for f, a in sorted(pycompat.iteritems(actions)):
                 m, args, msg = a
+                if m == ACTION_GET_OTHER_AND_STORE:
+                    m = ACTION_GET
                 repo.ui.debug(b' %s: %s -> %s\n' % (f, msg, m))
                 if f in fbids:
                     d = fbids[f]
@@ -1813,6 +1840,7 @@
             ACTION_KEEP,
             ACTION_PATH_CONFLICT,
             ACTION_PATH_CONFLICT_RESOLVE,
+            ACTION_GET_OTHER_AND_STORE,
         )
     }
 
@@ -1835,6 +1863,11 @@
 
     updated, merged, removed = 0, 0, 0
     ms = mergestate.clean(repo, wctx.p1().node(), mctx.node(), labels)
+
+    # add ACTION_GET_OTHER_AND_STORE to mergestate
+    for e in actions[ACTION_GET_OTHER_AND_STORE]:
+        ms.addmergedother(e[0])
+
     moves = []
     for m, l in actions.items():
         l.sort()
@@ -2415,6 +2448,7 @@
                     ACTION_EXEC,
                     ACTION_REMOVE,
                     ACTION_PATH_CONFLICT_RESOLVE,
+                    ACTION_GET_OTHER_AND_STORE,
                 ):
                     msg = _(b"conflicting changes")
                     hint = _(b"commit or update --clean to discard changes")
@@ -2477,6 +2511,10 @@
                 actions[m] = []
             actions[m].append((f, args, msg))
 
+        # ACTION_GET_OTHER_AND_STORE is a ACTION_GET + store in mergestate
+        for e in actions[ACTION_GET_OTHER_AND_STORE]:
+            actions[ACTION_GET].append(e)
+
         if not util.fscasesensitive(repo.path):
             # check collision between files only in p2 for clean update
             if not branchmerge and (