nixpkgs/pkgs/build-support/fetchpatch/default.nix
John Ericson 9bd437d4b4 fetchpatch: Add support for an arbitrary extra prefix
We still ensure the old and new ones start, respectfully, with `a/` and
`b/`. Use with `stripLen` to ensure tha the old `a/` and `/b` are gone
if a new prefix is added.
2018-01-18 12:19:49 -05:00

30 lines
1.1 KiB
Nix

# This function downloads and normalizes a patch/diff file.
# This is primarily useful for dynamically generated patches,
# such as GitHub's or cgit's, where the non-significant content parts
# often change with updating of git or cgit.
# stripLen acts as the -p parameter when applying a patch.
{ lib, fetchurl, patchutils }:
{ stripLen ? 0, extraPrefix ? null, excludes ? [], ... }@args:
fetchurl ({
postFetch = ''
tmpfile="$TMPDIR/${args.sha256}"
"${patchutils}/bin/lsdiff" "$out" \
| sort -u | sed -e 's/[*?]/\\&/g' \
| xargs -I{} \
"${patchutils}/bin/filterdiff" \
--include={} \
--strip=${toString stripLen} \
${lib.optionalString (extraPrefix != null) ''
--addoldprefix=a/${extraPrefix} \
--addnewprefix=b/${extraPrefix} \
''} \
--clean "$out" > "$tmpfile"
${patchutils}/bin/filterdiff \
-p1 \
${builtins.toString (builtins.map (x: "-x ${x}") excludes)} \
"$tmpfile" > "$out"
${args.postFetch or ""}
'';
} // builtins.removeAttrs args ["stripLen" "extraPrefix" "excludes" "postFetch"])