filemerge: use non-minimal conflict marker regions (BC)

As extensively detailed by Pierre-Yves[1], simplemerge's minimal
markers can result in hopeless confusion for many common merges. As it
happens, we accidentally inherited this behavior when we borrowed
simplemerge from bzr; it is not the behavior used by RCS's merge(1),

Since merge(1) (and not bzr) is what we aim to emulate when emulating
RCS's merge markers, we simply turn this feature off. This brings us
in line with the behavior of CVS, SVN, and Git as a bonus.

(NB: using conflict markers with Mercurial is discouraged.)

[1] http://markmail.org/message/wj5mh3lc46czlvld

convert glob tessa

mercurial/filemerge.py

@@ -217,7 +217,7 b' def _imerge(repo, mynode, orig, fcd, fco'
 
         ui = repo.ui
 
-        r = simplemerge.simplemerge(ui, a, b, c, label=labels)
+        r = simplemerge.simplemerge(ui, a, b, c, label=labels, no_minimal=True)
         return True, r
     return False, 0
 

tests/test-conflict.t

@@ -47,13 +47,16 b''
 
   $ cat a
   Small Mathematical Series.
+  <<<<<<< local: 618808747361 - test: branch2
   1
   2
   3
-  <<<<<<< local: 618808747361 - test: branch2
   6
   8
   =======
+  1
+  2
+  3
   4
   5
   >>>>>>> other: c0c68e4fe667  - test: branch1
@@ -78,13 +81,16 b' Verify custom conflict markers'
 
   $ cat a
   Small Mathematical Series.
+  <<<<<<< local: test 2
   1
   2
   3
-  <<<<<<< local: test 2
   6
   8
   =======
+  1
+  2
+  3
   4
   5
   >>>>>>> other: test 1
@@ -105,13 +111,16 b' Verify line splitting of custom conflict'
 
   $ cat a
   Small Mathematical Series.
+  <<<<<<< local: test 2
   1
   2
   3
-  <<<<<<< local: test 2
   6
   8
   =======
+  1
+  2
+  3
   4
   5
   >>>>>>> other: test 1
@@ -145,13 +154,16 b' Verify line trimming of custom conflict '
 
   $ cat a
   Small Mathematical Series.
+  <<<<<<< local: 123456789012345678901234567890123456789012345678901234567890\xe3\x81\x82... (esc)
   1
   2
   3
-  <<<<<<< local: 123456789012345678901234567890123456789012345678901234567890\xe3\x81\x82... (esc)
   6
   8
   =======
+  1
+  2
+  3
   4
   5
   >>>>>>> other: branch1
@@ -172,13 +184,16 b' Verify basic conflict markers'
 
   $ cat a
   Small Mathematical Series.
+  <<<<<<< local
   1
   2
   3
-  <<<<<<< local
   6
   8
   =======
+  1
+  2
+  3
   4
   5
   >>>>>>> other