Make sure HGMERGE doesn't interfere with the test:

  $ unset HGMERGE

  $ hg init

Initial file contents:

  $ echo "line 1" > f

  $ echo "line 2" >> f

  $ echo "line 3" >> f

  $ hg ci -Am "revision 0"

  adding f

  $ cat f

  line 1

  line 2

  line 3

Branch 1: editing line 1:

  $ sed 's/line 1/first line/' f > f.new

  $ mv f.new f

  $ hg ci -Am "edited first line"

Branch 2: editing line 3:

  $ hg update 0

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ sed 's/line 3/third line/' f > f.new

  $ mv f.new f

  $ hg ci -Am "edited third line"

  created new head

Merge using internal:fail tool:

  $ echo "[merge-patterns]" > .hg/hgrc

  $ echo "* = internal:fail" >> .hg/hgrc

  $ hg merge

  0 files updated, 0 files merged, 0 files removed, 1 files unresolved

  use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon

  [1]

  $ cat f

  line 1

  line 2

  third line

  $ hg stat

  M f

Merge using internal:local tool:

  $ hg update -C 2

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ sed 's/internal:fail/internal:local/' .hg/hgrc > .hg/hgrc.new

  $ mv .hg/hgrc.new .hg/hgrc

  $ hg merge

  0 files updated, 1 files merged, 0 files removed, 0 files unresolved

  (branch merge, don't forget to commit)

  $ cat f

  line 1

  line 2

  third line

  $ hg stat

  M f

Merge using internal:other tool:

  $ hg update -C 2

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ sed 's/internal:local/internal:other/' .hg/hgrc > .hg/hgrc.new

  $ mv .hg/hgrc.new .hg/hgrc

  $ hg merge

  0 files updated, 1 files merged, 0 files removed, 0 files unresolved

  (branch merge, don't forget to commit)

  $ cat f

  first line

  line 2

  line 3

  $ hg stat

  M f

Merge using default tool:

  $ hg update -C 2

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ rm .hg/hgrc

  $ hg merge

  merging f

  0 files updated, 1 files merged, 0 files removed, 0 files unresolved

  (branch merge, don't forget to commit)

  $ cat f

  first line

  line 2

  third line

  $ hg stat

  M f