Merging svn using Meld

Meld is a great tool, and it can ease the pain of svn greatly. Unfortunately, until recently (not yet in version 1.3), it did not support a merge result file argument.

But now it does! (still experimental and not officially released)

So how to use it (under linux, or unix compatible systems):

Check if your Meld is > 1.3, if not,

Check the meld website to see if Meld > 1.3 is released and install it.

If you got Meld > 1.3 go ahead with "SVN Meld glue".

Build Meld source

Fetch the Meld source and build it using:
cd ~/bin
git clone git://git.gnome.org/meld
cd meld
make
./bin/meld

If all went fine, you should be running Meld > 1.3 now. Close it off.

SVN Meld glue

Start a text editor.
Write the following to a file named ~/bin/svn-merge-meld

#!/usr/bin/env python
# svn merge-tool python wrapper for meld
import sys
import subprocess

# path to meld ($ which meld)
meld = "~/bin/meld/bin/meld"
log = False
f = open('/tmp/svn-merge-meld.log', 'a')

def main():
if log:
f.write("call: %r\n" % sys.argv)

# file paths
base   = sys.argv[1]
theirs = sys.argv[2]
mine   = sys.argv[3]
merged = sys.argv[4]
partial = sys.argv[5]

# the call to meld
cmd = [meld, mine, base, theirs, merged]

# Call meld, making sure it exits correctly
subprocess.check_call(cmd)

try:
main()
except Exception as e:
print "Oh noes, an error: %r" % e
if log:
 f.write("Error: %r\n" % e)
sys.exit(-1)

Change the file permissions to +x:
chmod +x ~/bin/svn-merge-meld

With the text editor, edit ~/.subversion/config
Locate this section:

### Set merge-tool-cmd to the command used to invoke your external
### merging tool of choice. Subversion will pass 4 arguments to
### the specified command: base theirs mine merged
# merge-tool-cmd = merge_command

Add this below it:
merge-tool-cmd = ~/bin/svn-merge-meld

Usage

svn merge -r 14829:HEAD http://path/to/trunk my/branch
Select: (p) postpone, (df) diff-full, (e) edit, (r) resolved,
  (mc) mine-conflict, (tc) theirs-conflict,
  (s) show all options:

Press l-Enter (the letter L) to fire up Meld.

In this case:

• the left side is the change in my/branch
• the middle part is the merge result which you can edit
• the right side are the changes in the trunk

Merge, save and quit, then in the console press r-Enter, and your done. (Almost) painless merging in svn!

References

• Meld
• Piotr Piastucki's Meld patch
• John's earlier svn-meld integration script