quilt is an excellent patch management utility. Especially upgrading a stack of many patches is often a pain in the ass. Using quilt all that matters are the right commands at the right time. :)

Not every project is using quilt, but that's not a problem, one can use it nevertheless.

Assuming the patches are to be applied in alphabetical order and residing in ${PATCHES_DIR}, after unpacking the source package and cd'ing into the root directory, you can use the following script to import all patches in one run:

for i in ${PATCHES_DIR}/*.patch; do 
        quilt import -P `basename $i` $i 
        quilt push `basename $i`
done

Go back to the initial state:

quilt pop -a

To actually update the patches, run:

while quilt push; do 
        quilt refresh -p 1 -u --no-index --backup
done

you will find the updated patches inside patches/ along with their original version suffixed with tilde.

To get a total diff, use this script:

for i in patches/*.patch; do 
        diff ${i}~ $i
done >quilt_check.log

sometimes some grep'ing is helpful, e.g.:

cat quilt_check.log| grep -v -- '---' | grep -v '@@' | grep -v '+++' | grep -v 'diff ' | grep -ve '[0-9]*c'

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