Merge branch 'maint'

* maint:
  difftool: provide basename to external tools
  git-difftool.txt: correct the description of $BASE and describe $MERGED

diff --combined Documentation/git-difftool.txt
index 6fffbc7bf89d01b14505c03993de9d97d37e9404,573843211112a6efb7b296bbc5b11894c01dd8cd..db87f1d42382e32d7e3ee94e5c3d0a032b7430e2
--- 1/Documentation/git-difftool.txt
--- 2/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@@ -7,14 -7,13 +7,14 @@@ git-difftool - Show changes using commo
  
  SYNOPSIS
  --------
 -'git difftool' [<options>] <commit>{0,2} [--] [<path>...]
 +'git difftool' [<options>] [<commit> [<commit>]] [--] [<path>...]
  
  DESCRIPTION
  -----------
  'git difftool' is a git command that allows you to compare and edit files
  between revisions using common diff tools.  'git difftool' is a frontend
 -to 'git diff' and accepts the same options and arguments.
 +to 'git diff' and accepts the same options and arguments. See
 +linkgit:git-diff[1].
  
  OPTIONS
  -------
@@@ -56,14 -55,16 +56,16 @@@ the configured command line will be inv
  variables available: `$LOCAL` is set to the name of the temporary
  file containing the contents of the diff pre-image and `$REMOTE`
  is set to the name of the temporary file containing the contents
- of the diff post-image.  `$BASE` is provided for compatibility
- with custom merge tool commands and has the same value as `$LOCAL`.
+ of the diff post-image.  `$MERGED` is the name of the file which is
+ being compared. `$BASE` is provided for compatibility
+ with custom merge tool commands and has the same value as `$MERGED`.
  
  -x <command>::
  --extcmd=<command>::
        Specify a custom command for viewing diffs.
        'git-difftool' ignores the configured defaults and runs
        `$command $LOCAL $REMOTE` when this option is specified.
+       Additionally, `$BASE` is set in the environment.
  
  -g::
  --gui::