Fix pkg symlink removal introduced in the two phase package removal feature.

NEWS

@@ -1,5 +1,9 @@
 xbps-0.33 (???):
 
+ * While checking file permissions for package files removal, make sure
+   to not dereference symbolic links, because a symlink might point to
+   a file in the rootfs, which won't have the same uid/gid.
+
  * Fixed issue #31: https://github.com/voidlinux/xbps/issues/31
 
  * New configuration file format with a custom C parser, simpler

lib/package_remove.c

@@ -30,6 +30,8 @@
 #include <errno.h>
 #include <dirent.h>
 #include <libgen.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 #include "xbps_api_impl.h"
 
@@ -44,6 +46,7 @@ check_remove_pkg_files(struct xbps_handle *xhp,
 	const char *file;
 	char *path = NULL;
 	bool fail = false;
+	int fd = 0;
 
 	for (uint8_t i = 0; i < __arraycount(objs); i++) {
 		array = xbps_dictionary_get(pkgd, objs[i]);
@@ -57,7 +60,7 @@ check_remove_pkg_files(struct xbps_handle *xhp,
 		while ((obj = xbps_object_iterator_next(iter))) {
 			xbps_dictionary_get_cstring_nocopy(obj, "file", &file);
 			path = xbps_xasprintf("%s/%s", xhp->rootdir, file);
-			if (access(path, W_OK) == -1) {
+			if (faccessat(fd, path, W_OK, AT_SYMLINK_NOFOLLOW) == -1) {
 				if (errno != ENOENT) {
 					/*
 					 * only bail out if something else than ENOENT

tests/xbps/libxbps/shell/remove_test.sh

@@ -67,7 +67,38 @@ remove_symlinks_body() {
 	atf_check_equal $rv 0
 }
 
+# 3rd test: make sure that symlinks to the rootfs are also removed.
+atf_test_case remove_symlinks_from_root
+
+remove_symlinks_from_root_head() {
+	atf_set "descr" "Tests for package removal: symlink from root test"
+}
+
+remove_symlinks_from_root_body() {
+	mkdir some_repo
+	mkdir -p pkg_A/bin
+	ln -sf /bin/bash pkg_A/bin/bash
+	ln -sf /bin/bash pkg_A/bin/sh
+
+	cd some_repo
+	xbps-create -A noarch -n A-1.0_1 -s "A pkg" ../pkg_A
+	atf_check_equal $? 0
+	xbps-rindex -a *.xbps
+	atf_check_equal $? 0
+	cd ..
+	xbps-install -r root -C null.conf --repository=$PWD/some_repo -y A
+	atf_check_equal $? 0
+	xbps-remove -r root -Ryv A
+	atf_check_equal $? 0
+	rv=0
+	if [ -h root/bin/bash -o -h root/bin/sh ]; then
+	        rv=1
+	fi
+	atf_check_equal $rv 0
+}
+
 atf_init_test_cases() {
 	atf_add_test_case keep_base_symlinks
 	atf_add_test_case remove_symlinks
+	atf_add_test_case remove_symlinks_from_root
 }