This package supports working with patch files using quilt.

To regenerate the quilt series file run:
./gen-quilt-series.sh

Setup environment:
export QUILT_PATCHES=$PWD

Setup the source:
./quilt-patch.sh [-f]

Use `-f` if you want to have quilt-patch always remove the existing
source directory before starting. Otherwise you'll be patching on top of
an already patched tree generated perhaps by `*pkg prep`.

To add a new patch:

Option 1: Create a new patch:

cd flex-2.6.1/
quilt new flex-rh1439367.patch
quilt add tests/test-bison-yylloc/parser.y
# edit tests/test-bison-yylloc/parser.y
# you may add and edit several files in the same fashion

Option 2: Add an already prepared patch (e.g. from an upstream commit):

cd flex-2.6.1/
quilt import -P flex-rh1439367.patch ~/backport/obsolete-bison.patch
quilt push # if this fails, manually deal with conflicts (as in Option 1)

Finally:
quilt refresh -p ab
cd ..
git add flex-rh1439367.patch
# edit flex.spec to build with the new patch
git add flex.spec
git commit

You're done!