pkg: Install *.LEGAL.txt as documentation

These are not really part of the cockpit package data, but
documentation, so put them into /usr/share/doc/cockpit/legal/ instead.

Also, out of the 61 *.LEGAL.txt files that esbuild creates, 40 are empty
(0 bytes). Installing them is just noise, so weed them out. See
evanw/esbuild#3670

Author: martinpitt

pkg/Makefile.am

@@ -34,9 +34,11 @@ $(DIST_STAMP): $(srcdir)/package-lock.json $(PKG_INPUTS)
 
 EXTRA_DIST += build.js files.js package.json package-lock.json
 
+# don't install empty LEGAL.txt files, see https://github.com/evanw/esbuild/issues/3670
 INSTALL_DATA_LOCAL_TARGETS += install-bundles
 install-bundles:
-	cd $(srcdir)/dist; find */* -type f -exec install -D -m 644 '{}' '$(abspath $(DESTDIR)$(datadir))/cockpit/{}' \;
+	cd $(srcdir)/dist; find */* -type f ! -name '*.LEGAL.txt' -exec install -D -m 644 '{}' '$(abspath $(DESTDIR)$(datadir))/cockpit/{}' \;
+	find $(srcdir)/dist -name '*.LEGAL.txt' ! -empty -exec install --target-directory '$(abspath $(DESTDIR)$(docdir))/legal' '{}' -D -m 644 '{}'  \;
 
 UNINSTALL_LOCAL_TARGETS += uninstall-bundles
 uninstall-bundles: