simple squash without rebase

gistfile1.txt

## within current branch, squashes all commits that are ahead of master down into one
## useful if you merged with upstream in the middle of your commits (rebase could get very ugly if this is the case)
 
## commit any working changes on branch "mybranchname", then...
git checkout master
git checkout -b mybranchname_temp
git merge --squash mybranchname
git commit -am "Message describing all squashed commits"
git branch -m mybranchname mybranchname_unsquashed
git branch -m mybranchname
 
## optional, not recommended if you want to keep the unsquashed history around for a bit longer
git branch -D mybranchname_unsquashed
 
## if squashing already-pushed commits...
git push --force

Brilliant, thanks for this

cool

Note that you might face the issue of setting tracking information as well (connecting your new squashed branch to your remote one). To handle this you will need to do:
git branch --set-upstream-to=origin/myfeaturebranch myfeaturebranch