DiffMerge requires wrapper script

[michaellopez]

As I have reported at SourceGear forums DiffMerge requires a wrapper script to work from command line.

My reply at SourceGear forum

The error
/build/sgdm400/Apple/intel/Release_patched/wxWidgets-3.0.0-rc1/src/common/arrstr.cpp(368): assert "nIndex < m_nCount" failed in RemoveAt(): bad index in wxArrayString::Remove is due to calling the program from the command line without a path, like having it in $PATH

ls -l | grep diffmerge
  diffmerge -> /opt/homebrew-cask/Caskroom/diffmerge/4.2.0.697/DiffMerge.app/Contents/MacOS/DiffMerge

$ /usr/local/bin/diffmerge <--- works, no error
$ /opt/homebrew-cask/Caskroom/diffmerge/4.2.0.697/DiffMerge.app/Contents/MacOS/DiffMerge <--- works, no error
$ diffmerge <--- works, but gives error

So either use absolute path when calling the program or use a small wrapper script. Save this as /usr/local/bin/diffmerge and make it executable with chmod +x /usr/local/bin/diffmerge

#!/bin/bash
/opt/homebrew-cask/Caskroom/diffmerge/4.2.0.697/DiffMerge.app/Contents/MacOS/DiffMerge $@

End reply

So I wanted to try and submit my workaround to the cask formula, but I can't figure out the best and recommended way to approach it. What I want to accomplish is making the formula create the small wrapper script above instead of binary 'DiffMerge.app/Contents/MacOS/DiffMerge', :target => 'diffmerge' which is currently does now.

[vitorgalvao]

We don’t yet have a solution, but we’re discussing it. You’re welcome to join in.

[michaellopez]

@vitorgalvao A SourceGear representative pointed me to a script that is included with the dmg file. But for that to work properly I would need to replace strings inside the script file to point to the files homebrew cask installs. I can't seem to find a documented way of doing this, neither in documentation or other cask formulae. Is homebrew's "inreplace" supported?

[vitorgalvao]

Not sure. Pinging @phinze @ndr-qef.

[darkn3rd]

The Docs (which seem to be only applicable to DiffMerge.4.2.0.697.intel.stable.dmg):

sudo cp Extras/diffmerge.sh /usr/bin/diffmerge
sudo chmod 755 /usr/bin/diffmerge
sudo cp Extras/diffmerge.1 /usr/share/man/man1/diffmerge.1
sudo chmod 644 /usr/share/man/man1/diffmerge.1

Reference: https://sourcegear.com/diffmerge/webhelp/sec__inst__mac.html

I have been inspecting the installer package (DiffMerge.4.2.0.697.intel.stable.pkg), and noted that it has a Payload (gzip/cpio) that includes the /usr/bin/diffmerge wrapper script:

#!/bin/sh
## A little script to make it easier to launch DiffMerge from the command line.
## Install this script into a folder in your path, such as /usr/bin or /usr/local/bin.
##
## Version 4.2.0.697
## Copyright (C) 2003-2013 SourceGear LLC. All Rights Reserved.
##############################################################################

## Change DIFFMERGE_PATH to point to where you installed DiffMerge

DIFFMERGE_PATH=/Applications/DiffMerge.app

## The actual executable is hidden inside the .app bundle.

DIFFMERGE_EXE=${DIFFMERGE_PATH}/Contents/MacOS/DiffMerge

## Launch DiffMerge using the given command line arguments.  Use --help for
## additional information or see the man page distributed along with this
## shell script.

exec ${DIFFMERGE_EXE} --nosplash "$@"

Thus it looks like the manual steps that are required for the DMG installation, are performed by the PKG install.

[darkn3rd]

Note this is marked as an enhancement request. This is a BUG. Having a program not crash should not be an enhancement request.

[darkn3rd]

As a workaround for command line installations, I am recommending users at my work use until this is fixed:

curl -O http://download-us.sourcegear.com/DiffMerge/4.2.0/DiffMerge.4.2.0.697.intel.stable.pkg
sudo installer -pkg ~/Downloads/DiffMerge.4.2.0.697.intel.stable.pkg -target /

[jawshooah]

Seems the obvious solution would be to just use the pkg installer rather than the dmg. What do you think, @vitorgalvao?

[vitorgalvao]

Seems the obvious solution would be to just use the pkg installer rather than the dmg. What do you think, @vitorgalvao?

Yep, I agree.