effectflag: detect when meta changed

Store in effect flag when the meta changed between the predecessor and its
successors. We blacklisted some known meta that would always changed when
another flag change. For example rebase would always add a meta rebase-source
while the effect flag parents will already detect this situation.

It can happens with various hg commands.

Differential Revision: https://phab.mercurial-scm.org/D540

mercurial/obsutil.py

@@ -7,6 +7,8 b''
 
 from __future__ import absolute_import
 
+import re
+
 from . import (
     phases,
     util
@@ -309,11 +311,27 b' def foreground(repo, nodes):'
 EFFECTFLAGFIELD = "ef1"
 
 DESCCHANGED = 1 << 0 # action changed the description
+METACHANGED = 1 << 1 # action change the meta
 PARENTCHANGED = 1 << 2 # action change the parent
 USERCHANGED = 1 << 4 # the user changed
 DATECHANGED = 1 << 5 # the date changed
 BRANCHCHANGED = 1 << 6 # the branch changed
 
+METABLACKLIST = [
+    re.compile('^branch$'),
+    re.compile('^.*-source$'),
+    re.compile('^.*_source$'),
+    re.compile('^source$'),
+]
+
+def metanotblacklisted(metaitem):
+    """ Check that the key of a meta item (extrakey, extravalue) does not
+    match at least one of the blacklist pattern
+    """
+    metakey = metaitem[0]
+
+    return not any(pattern.match(metakey) for pattern in METABLACKLIST)
+
 def geteffectflag(relation):
     """ From an obs-marker relation, compute what changed between the
     predecessor and the successor.
@@ -343,6 +361,16 b' def geteffectflag(relation):'
         if changectx.parents() != source.parents():
             effects |= PARENTCHANGED
 
+        # Check if other meta has changed
+        changeextra = changectx.extra().items()
+        ctxmeta = filter(metanotblacklisted, changeextra)
+
+        sourceextra = source.extra().items()
+        srcmeta = filter(metanotblacklisted, sourceextra)
+
+        if ctxmeta != srcmeta:
+            effects |= METACHANGED
+
     return effects
 
 def getobsoleted(repo, tr):

tests/test-obsmarkers-effectflag.t

@@ -164,4 +164,4 b' amend closing the branch should be detec'
 check result
 
   $ hg debugobsolete -r .
-  2f599e54c1c6974299065cdf54e1ad640bfb7b5d 12c6238b5e371eea00fd2013b12edce3f070928b 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '0', 'operation': 'amend', 'user': 'test'}
+  2f599e54c1c6974299065cdf54e1ad640bfb7b5d 12c6238b5e371eea00fd2013b12edce3f070928b 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '2', 'operation': 'amend', 'user': 'test'}