tests/test-contrib.t

rust-nodemap: accounting for dead blocks

By the very append-only nature of the `NodeTree`, inserting
new blocks has the effect of making some of the older ones
useless as they become unreachable.

Therefore some automatic housekeeping will need to be provided.
This is standard procedure in the word of databases, under names
such as "repack" or "vacuum".

The new `masked_readonly_blocks()` will provide callers with
useful information to decide if the nodetree is ripe for
repacking, but all the `NodeTree` can provide is how many
blocks have been masked in the currently mutable part. Analysing
the readonly part would be way too long to do it for each
transaction and defeat the whole purpose of nodemap persistence.
Serializing callers (from the Python layer) will get this figure
before each extraction and maintain an aggregate counter of
unreachable blocks separately.

Note: at this point, the most efficient repacking is just to restart
afresh with a full rescan.

Differential Revision: https://phab.mercurial-scm.org/D8097

Set vars:

  $ CONTRIBDIR="$TESTDIR/../contrib"

Test simplemerge command:

  $ cp "$CONTRIBDIR/simplemerge" .
  $ echo base > base
  $ echo local > local
  $ cat base >> local
  $ cp local orig
  $ cat base > other
  $ echo other >> other

changing local directly

  $ "$PYTHON" simplemerge local base other && echo "merge succeeded"
  merge succeeded
  $ cat local
  local
  base
  other
  $ cp orig local

printing to stdout

  $ "$PYTHON" simplemerge -p local base other
  local
  base
  other

local:

  $ cat local
  local
  base

conflicts

  $ cp base conflict-local
  $ cp other conflict-other
  $ echo not other >> conflict-local
  $ echo end >> conflict-local
  $ echo end >> conflict-other

  $ "$PYTHON" simplemerge -p conflict-local base conflict-other
  base
  <<<<<<< conflict-local
  not other
  =======
  other
  >>>>>>> conflict-other
  end
  [1]

1 label

  $ "$PYTHON" simplemerge -p -L foo conflict-local base conflict-other
  base
  <<<<<<< foo
  not other
  =======
  other
  >>>>>>> conflict-other
  end
  [1]

2 labels

  $ "$PYTHON" simplemerge -p -L foo -L bar conflict-local base conflict-other
  base
  <<<<<<< foo
  not other
  =======
  other
  >>>>>>> bar
  end
  [1]

3 labels

  $ "$PYTHON" simplemerge -p -L foo -L bar -L base conflict-local base conflict-other
  base
  <<<<<<< foo
  not other
  end
  ||||||| base
  =======
  other
  end
  >>>>>>> bar
  [1]

too many labels

  $ "$PYTHON" simplemerge -p -L foo -L bar -L baz -L buz conflict-local base conflict-other
  abort: can only specify three labels.
  [255]

binary file

  $ "$PYTHON" -c "f = open('binary-local', 'w'); f.write('\x00'); f.close()"
  $ cat orig >> binary-local
  $ "$PYTHON" simplemerge -p binary-local base other
  warning: binary-local looks like a binary file.
  [1]

binary file --text

  $ "$PYTHON" simplemerge -a -p binary-local base other 2>&1
  warning: binary-local looks like a binary file.
  \x00local (esc)
  base
  other

help

  $ "$PYTHON" simplemerge --help
  simplemerge [OPTS] LOCAL BASE OTHER
  
      Simple three-way file merge utility with a minimal feature set.
  
      Apply to LOCAL the changes necessary to go from BASE to OTHER.
  
      By default, LOCAL is overwritten with the results of this operation.
  
  options:
   -L --label       labels to use on conflict markers
   -a --text        treat all files as text
   -p --print       print results instead of overwriting LOCAL
      --no-minimal  no effect (DEPRECATED)
   -h --help        display help and exit
   -q --quiet       suppress output

wrong number of arguments

  $ "$PYTHON" simplemerge
  simplemerge: wrong number of arguments
  simplemerge [OPTS] LOCAL BASE OTHER
  
      Simple three-way file merge utility with a minimal feature set.
  
      Apply to LOCAL the changes necessary to go from BASE to OTHER.
  
      By default, LOCAL is overwritten with the results of this operation.
  
  options:
   -L --label       labels to use on conflict markers
   -a --text        treat all files as text
   -p --print       print results instead of overwriting LOCAL
      --no-minimal  no effect (DEPRECATED)
   -h --help        display help and exit
   -q --quiet       suppress output
  [1]

bad option

  $ "$PYTHON" simplemerge --foo -p local base other
  simplemerge: option --foo not recognized
  simplemerge [OPTS] LOCAL BASE OTHER
  
      Simple three-way file merge utility with a minimal feature set.
  
      Apply to LOCAL the changes necessary to go from BASE to OTHER.
  
      By default, LOCAL is overwritten with the results of this operation.
  
  options:
   -L --label       labels to use on conflict markers
   -a --text        treat all files as text
   -p --print       print results instead of overwriting LOCAL
      --no-minimal  no effect (DEPRECATED)
   -h --help        display help and exit
   -q --quiet       suppress output
  [1]