+# Some projects carry local adjustments for gnulib modules via patches in
+# a gnulib patch directory whose default name is gl/ (defined in bootstrap
+# via local_gl_dir=gl). Those patches become stale as the originals evolve
+# in gnulib. Use this rule to refresh any stale patches. It applies each
+# patch to the original in $(gnulib_dir) and uses the temporary result to
+# generate a fuzz-free .diff file. If you customize the name of your local
+# gnulib patch directory via bootstrap.conf, this rule detects that name.
+# Run this from a non-VPATH (i.e., srcdir) build directory.
+.PHONY: refresh-gnulib-patches
+refresh-gnulib-patches:
+ gl=gl; \
+ if test -f bootstrap.conf; then \
+ t=$$(perl -lne '/^\s*local_gl_dir=(\S+)/ and $$d=$$1;' \
+ -e 'END{defined $$d and print $$d}' bootstrap.conf); \
+ test -n "$$t" && gl=$$t; \
+ fi; \
+ for diff in $$(cd $$gl; git ls-files | grep '\.diff$$'); do \
+ b=$$(printf %s "$$diff"|$(SED) 's/\.diff$$//'); \
+ VERSION_CONTROL=none \
+ patch "$(gnulib_dir)/$$b" "$$gl/$$diff" || exit 1; \
+ ( cd $(gnulib_dir) || exit 1; \
+ git diff "$$b" > "../$$gl/$$diff"; \
+ git checkout $$b ) || exit 1; \
+ done
+