diff -r 4d5d5009bd75 -r 18a3274ed675 mercurial/configitems.py
--- a/mercurial/configitems.py	Sat Oct 14 17:05:41 2017 +0200
+++ b/mercurial/configitems.py	Sun Oct 08 20:37:13 2017 +0200
@@ -544,6 +544,60 @@
 coreconfigitem('merge', 'preferancestor',
         default=lambda: ['*'],
 )
+coreconfigitem('merge-tools', '.*',
+    default=None,
+    generic=True,
+)
+coreconfigitem('merge-tools', r'.*\.args$',
+    default="$local $base $other",
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.binary$',
+    default=False,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.check$',
+    default=list,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.checkchanged$',
+    default=False,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.executable$',
+    default=dynamicdefault,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.fixeol$',
+    default=False,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.gui$',
+    default=False,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.priority$',
+    default=0,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.premerge$',
+    default=dynamicdefault,
+    generic=True,
+    priority=-1,
+)
+coreconfigitem('merge-tools', r'.*\.symlink$',
+    default=False,
+    generic=True,
+    priority=-1,
+)
 coreconfigitem('pager', 'attend-.*',
     default=dynamicdefault,
     generic=True,