Re: [PATCH v2] git gui: add directly calling merge tool from gitconfig

[Junio C Hamano <gitster@pobox.com>]

"ToBoMi via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: deboeto <tobias.boesch@miele.com>

Use the same ident (human readable name plus e-mail address) you
have on your Signed-off-by: line below for this "From: " in-body
header.

> git gui can open a merge tool when conflicts are
> detected (Right click in the diff of the file with
> conflicts).
> The merge tools that are allowed to
> use are hard coded into git gui.
>
> If one wants to add a new merge tool it has to be
> added to git gui through a source code change.
> This is not convenient in comparison to how it
> works in git (without gui).
>
> git itself has configuration options for a merge tools
> path and command in the git config.
> New merge tools can be set up there without a
> source code change.

Even if you configure an unknown tool, it would not get any benefit
from what git-{diff,merge}tool--lib.sh gives the known diff/merge
backends, would it?  Instead of a more thorough support for known
tools done in setup_tool(), an unknown tool would be handled by
setup_user_tool() in git-mergetool-lib.sh which gives somewhat
degraded support.

So "can be set up without" may be true, but giving an impression
that a tool that is set up like so would work just like a known tool
is misleading.

By the way, we do ask contributors to avoid overly long lines,
50-col limt is a bit overly short and makes the resulting text
harder to read than necessary.

> Those options are used only by pure git in
> contrast to git gui. git calls the configured
> merge tools directly from the config while git
> Gui doesn't.
>
> With this change git gui can call merge tools
> configured in the gitconfig directly without a
> change in git gui source code.
> It needs a configured merge.tool and a configured
> mergetool.cmd config entry.

OK.

> gitconfig example:
> [merge]
> 	tool = vscode
> [mergetool "vscode"]
> 	path = the/path/to/Code.exe
> 	cmd = \"Code.exe\" --wait --merge \"$LOCAL\" \"$REMOTE\" \"$BASE\" \"$MERGED\"
>
> Without the mergetool.cmd configuration and an
> unsupported merge.tool entry, git gui behaves
> mainly as before this change and informs the user
> about an unsupported merge tool, but now also
> shows a hint to add a config entry for the tool
> in gitconfig.
>
> If a wrong mergetool.cmd is configured by accident
> it is beeing handled by git gui already. In this

"is beeing" -> "is being", but "it gets handled by Git GUI already"
should be sufficient.

> case git gui informs the user that the merge tool
> couldn't be opened. This behavior is preserved by
> this change and should not change.
>
> Beyond compare 3 and Visual Studio code were
> tested as manually configured merge tools.

Quote proper nouns for readability?  E.g. 

    "Beyond Compare 3" and "Visual Studio Code" were ...

Thanks.