[PATCH v2 0/5] difftool and mergetool improvements

[Denton Liu <liu.denton@gmail.com>]

Thanks for the review, Eric.

Hopefully, these changes have addressed the concerns that you've raised.

---

Changes since v1:

* Introduce get_merge_tool_guessed function instead of changing
  get_merge_tool
* Remove unnecessary if-tower in mutual exclusivity logic

Denton Liu (5):
  t7610: add mergetool --gui tests
  mergetool: use get_merge_tool_guessed function
  mergetool: fallback to tool when guitool unavailable
  difftool: make --gui, --tool and --extcmd mutually exclusive
  difftool: fallback on merge.guitool

 Documentation/git-difftool.txt       |  4 ++-
 Documentation/git-mergetool--lib.txt |  9 +++++-
 Documentation/git-mergetool.txt      |  4 ++-
 builtin/difftool.c                   | 13 ++++-----
 git-mergetool--lib.sh                | 39 ++++++++++++++++++--------
 git-mergetool.sh                     | 11 ++------
 t/t7610-mergetool.sh                 | 41 ++++++++++++++++++++++++++++
 t/t7800-difftool.sh                  | 24 ++++++++++++++++
 8 files changed, 114 insertions(+), 31 deletions(-)

Range-diff against v1:
1:  678f9b11fc = 1:  678f9b11fc t7610: add mergetool --gui tests
2:  692875cf4b ! 2:  e928db892e mergetool: use get_merge_tool function
    @@ -1,15 +1,19 @@
     Author: Denton Liu <liu.denton@gmail.com>
     
    -    mergetool: use get_merge_tool function
    +    mergetool: use get_merge_tool_guessed function
     
         In git-mergetool, the logic for getting which merge tool to use is
         duplicated in git-mergetool--lib, except for the fact that it needs to
         know whether the tool was guessed or not.
     
    -    Rewrite `get_merge_tool` to return whether or not the tool was guessed
    -    and make git-mergetool call this function instead of duplicating the
    -    logic. Also, let `$GIT_MERGETOOL_GUI` be set to determine whether or not
    -    the guitool will be selected.
    +    Write `get_merge_tool_guessed` to return whether or not the tool was
    +    guessed in addition to the actual tool and make git-mergetool call this
    +    function instead of duplicating the logic. Also, let
    +    `$GIT_MERGETOOL_GUI` be set to determine whether or not the guitool will
    +    be selected.
    +
    +    Make `get_merge_tool` use this function internally so that code
    +    duplication is reduced.
     
         Signed-off-by: Denton Liu <liu.denton@gmail.com>
     
    @@ -17,38 +21,32 @@
      --- a/Documentation/git-mergetool--lib.txt
      +++ b/Documentation/git-mergetool--lib.txt
     @@
    + 
      FUNCTIONS
      ---------
    - get_merge_tool::
    --	returns a merge tool.
    ++get_merge_tool_guessed::
     +	returns '$is_guessed:$merge_tool'. '$is_guessed' is 'true' if
     +	the tool was guessed, else 'false'. '$merge_tool' is the merge
     +	tool to use. '$GIT_MERGETOOL_GUI' may be set to 'true' to search
     +	for the appropriate guitool.
    ++
    + get_merge_tool::
    +-	returns a merge tool.
    ++	returns a merge tool. '$GIT_MERGETOOL_GUI' may be set to 'true'
    ++	to search for the appropriate guitool.
      
      get_merge_tool_cmd::
      	returns the custom command for a merge tool.
     
    - diff --git a/git-difftool--helper.sh b/git-difftool--helper.sh
    - --- a/git-difftool--helper.sh
    - +++ b/git-difftool--helper.sh
    -@@
    - 	then
    - 		merge_tool="$GIT_DIFF_TOOL"
    - 	else
    --		merge_tool="$(get_merge_tool)" || exit
    -+		merge_tool="$(get_merge_tool | sed -e 's/^[a-z]*://')" || exit
    - 	fi
    - fi
    - 
    -
      diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
      --- a/git-mergetool--lib.sh
      +++ b/git-mergetool--lib.sh
     @@
    + 	echo "$merge_tool_path"
      }
      
    - get_merge_tool () {
    +-get_merge_tool () {
    ++get_merge_tool_guessed () {
     +	is_guessed=false
      	# Check if a merge tool has been configured
     -	merge_tool=$(get_configured_merge_tool)
    @@ -61,6 +59,10 @@
      	fi
     -	echo "$merge_tool"
     +	echo "$is_guessed:$merge_tool"
    ++}
    ++
    ++get_merge_tool () {
    ++	get_merge_tool_guessed | sed -e 's/^[a-z]*://'
      }
      
      mergetool_find_win32_cmd () {
    @@ -81,7 +83,7 @@
     -			guessed_merge_tool=true
     -		fi
     +		IFS=':' read guessed_merge_tool merge_tool <<-EOF
    -+		$(GIT_MERGETOOL_GUI=$gui_tool get_merge_tool)
    ++		$(GIT_MERGETOOL_GUI=$gui_tool get_merge_tool_guessed)
     +		EOF
      	fi
      	merge_keep_backup="$(git config --bool mergetool.keepBackup || echo true)"
3:  de1b897a11 = 3:  24db1afeee mergetool: fallback to tool when guitool unavailable
4:  a272594bd2 = 4:  6f65b5c913 difftool: make --gui, --tool and --extcmd mutually exclusive
5:  4fc3f84bad = 5:  5a24772219 difftool: fallback on merge.guitool
-- 
2.21.0.1000.g11cd861522