Some diff/merge tool can handle multiple files but bzr does not support it

[methane]

Some diff viewer can show multiple pair of files with tabbed window (ex. WinMerge).

But when bzr diff --using=WinMergeU, bzr shows one pair of file and when it closed,
next pair is shown.
(qdiff and extmerge have same restriction.)

[Martin Pool (mbp)]

Thanks, that would be good to fix.

Can you tell us the syntax to run WinMerge on multiple files?

[methane (songofacandy)]

"/s" option.
WinMergeU.exe /s old1.txt new1.txt # new process starts.
WinMergeU.exe /s old2.txt new2.txt # new process shutdown soon and
diff is shown in new tab of previous window.

When all tab closed, first process exits.

--
Naoki INADA <email address hidden>

[Gary van der Merwe (garyvdm)]

I have started work on this.

I would like comments on the following design issue:

My patch will result in 2 modes:
* CLI mode, like the current behavior.
* A new GUI mode, where :
    - the sub process for each file are launched simultaneously (as per INADA's description.)
    - the temp files should only be deleted once *all* sub processes are closed.
    - possible idea that I want to test: were a file has been add or removed, pass a empty file to the diff app.

How do we control when we get what behavior? I have 2 ideas:
1. add a new command line option: "--using-gui".
2. Allow one to secifiy in the config files which apps us the gui mode.

I going to start out by implementing option 1 because I think it will be easier, but I would like other peoples comments.

[Gordon Tyler (doxxx)]

I trigger diff with an external tool mostly through the Explorer GUI, qcommit or qlog, where I wouldn't have the opportunity to specify the command-line option. So I think a GUI option will be required, but the command-line option is a good first step to make sure stuff works first.

I think the option should be described/named in terms of showing diffs one-at-a-time or all-at-once, since that's what it does. "GUI mode" vs "CLI mode" won't make much sense to most users.

[Gary van der Merwe (garyvdm)]

Meld did not work as expected. Rather than working as INADA described for winmerge, you can pass a list of files to diff. So in order to handle both ways, I've come up with this sintax:

To launch so that process are launched simultaneously:
bzr diff --using "winmerge.exe &"

or to launch process with a list of all files:
bzr diff --using "meld [--diff @old_path @new_path]"
or
bzr diff --using "meld [--diff]"

WIP branch linked. Still need to do tests and documentation.

[Dr Al (abudden)]

The open source python diff tool diffuse (http://diffuse.sourceforge.net) also supports multiple files in different tabs.