For those using v2.16 or better, you can simply use:
git add --renormalize . # Update index with renormalized files
git status # Show the files that will be normalized
git commit -m "Introduce end-of-line normalization"
These directions are straight out of the gitattributes. For older versions, the docs
(prior to v2.12) provide a different answer:
rm .git/index # Remove the index to force git to
git reset # re-scan the working directory
git status # Show files that will be normalized
git add -u
git add .gitattributes
git commit -m "Introduce end-of-line normalization"
Do this sequence after you have edited .gitattributes
.
Update
It appears some users have had trouble with the above instructions. Updated docs for gitattributes (2.12 to 2.14) shows a new set of instructions (after editing the .gitattributes files):
git read-tree --empty # Clean index, force re-scan of working directory
git add .
git status # Show files that will be normalized
git commit -m "Introduce end-of-line normalization"
Thanks to @vossad01 for pointing this out.
Also, with either solution the files in your working copy still retain their old line endings. If you want to update them, make sure your working tree is clean and use:
git rm --cached -r .
git reset --hard
Now the line endings will be correct in your working tree.