libarchive: do not extract unsafe symlinks unless $EXTRACT_UNSAFE_SYMLINKS=1

function                                             old     new   delta
unsafe_symlink_target                                  -     147    +147
unzip_main                                          2711    2732     +21
copy_file                                           1657    1678     +21
tar_main                                             999     971     -28
data_extract_all                                    1038     984     -54
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 2/2 up/down: 189/-82)           Total: 107 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/testsuite/tar.tests b/testsuite/tar.tests
index 1675b07..b7cd74c 100755
--- a/testsuite/tar.tests
+++ b/testsuite/tar.tests
@@ -279,7 +279,7 @@
 testing "tar does not extract into symlinks" "\
 >>/tmp/passwd && uudecode -o input && tar xf input 2>&1 && rm passwd; cat /tmp/passwd; echo \$?
 " "\
-tar: can't create symlink 'passwd' to '/tmp/passwd'
+tar: skipping unsafe symlink to '/tmp/passwd' in archive, set EXTRACT_UNSAFE_SYMLINKS=1 to extract
 0
 " \
 "" "\
@@ -299,7 +299,7 @@
 testing "tar -k does not extract into symlinks" "\
 >>/tmp/passwd && uudecode -o input && tar xf input -k 2>&1 && rm passwd; cat /tmp/passwd; echo \$?
 " "\
-tar: can't create symlink 'passwd' to '/tmp/passwd'
+tar: skipping unsafe symlink to '/tmp/passwd' in archive, set EXTRACT_UNSAFE_SYMLINKS=1 to extract
 0
 " \
 "" "\
@@ -324,11 +324,11 @@
 ' "\
 etc/ssl/certs/3b2716e5.0
 etc/ssl/certs/EBG_Elektronik_Sertifika_Hizmet_Sağlayıcısı.pem
+tar: skipping unsafe symlink to '/usr/share/ca-certificates/mozilla/EBG_Elektronik_Sertifika_Hizmet_Sağlayıcısı.crt' in archive, set EXTRACT_UNSAFE_SYMLINKS=1 to extract
 etc/ssl/certs/f80cc7f6.0
 usr/share/ca-certificates/mozilla/EBG_Elektronik_Sertifika_Hizmet_Sağlayıcısı.crt
 0
 etc/ssl/certs/3b2716e5.0 -> EBG_Elektronik_Sertifika_Hizmet_Sağlayıcısı.pem
-etc/ssl/certs/EBG_Elektronik_Sertifika_Hizmet_Sağlayıcısı.pem -> /usr/share/ca-certificates/mozilla/EBG_Elektronik_Sertifika_Hizmet_Sağlayıcısı.crt
 etc/ssl/certs/f80cc7f6.0 -> EBG_Elektronik_Sertifika_Hizmet_Sağlayıcısı.pem
 " \
 "" ""
@@ -346,9 +346,9 @@
 ' "\
 anything.txt
 symlink
+tar: skipping unsafe symlink to '/tmp' in archive, set EXTRACT_UNSAFE_SYMLINKS=1 to extract
 symlink/bb_test_evilfile
-tar: can't create symlink 'symlink' to '/tmp'
-1
+0
 ls: /tmp/bb_test_evilfile: No such file or directory
 ls: bb_test_evilfile: No such file or directory
 symlink/bb_test_evilfile