obsolete: add a devel.user.obsmarker

In tests, we often want to use a different username in obs-markers without
changing the default user. Add a 'devel.user.obsmarker'.

mercurial/configitems.py

@@ -158,6 +158,9 b" coreconfigitem('devel', 'warn-config',"
 coreconfigitem('devel', 'warn-config-default',
     default=None,
 )
+coreconfigitem('devel', 'user.obsmarker',
+    default=None,
+)
 coreconfigitem('diff', 'nodates',
     default=None,
 )

mercurial/obsolete.py

@@ -1035,6 +1035,10 b' def createmarkers(repo, relations, flag='
     if metadata is None:
         metadata = {}
     if 'user' not in metadata:
+        develuser = repo.ui.config('devel', 'user.obsmarker')
+        if develuser:
+            metadata['user'] = develuser
+        else:
         metadata['user'] = repo.ui.username()
 
     # Operation metadata handling

tests/test-obsmarker-template.t

@@ -42,8 +42,8 b' Test setup'
   $ mkcommit ROOT
   $ mkcommit A0
   $ echo 42 >> A0
-  $ HGUSER=test1 hg commit --amend -m "A1" --config devel.default-date="1234567890 0"
-  $ HGUSER=test2 hg commit --amend -m "A2" --config devel.default-date="987654321 0"
+  $ hg commit --amend -m "A1" --config devel.default-date="1234567890 0" --config devel.user.obsmarker=test1
+  $ hg commit --amend -m "A2" --config devel.default-date="987654321 0" --config devel.user.obsmarker=test2
 
   $ hg log --hidden -G
   @  changeset:   3:d004c8f274b9