[xen master] ] m4: use test instead of []

[patchbot@xxxxxxx]

commit e181db8ba4e0797b8f9b55996adfa71ffb5b4081
Author:     Wei Liu <wl@xxxxxxx>
AuthorDate: Tue Jun 2 10:01:38 2020 +0100
Commit:     Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
CommitDate: Tue Jun 2 17:46:32 2020 +0100

    ] m4: use test instead of []
    
    It is reported that [] was removed by autoconf, which caused the
    following error:
    
      ./configure: line 4681: -z: command not found
    
    Switch to test. That's what is used throughout our configure scripts.
    Also put the variable expansion in quotes.
    
    Signed-off-by: Wei Liu <wl@xxxxxxx>
    Reported-by: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>
    Fixes: 8a6b1665d987 ("configure: also add EXTRA_PREFIX to {CPP/LD}FLAGS")
    Signed-off-by: Wei Liu <wl@xxxxxxx>
    Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
    Release-acked-by: Paul Durrant <paul@xxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 m4/set_cflags_ldflags.m4 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/m4/set_cflags_ldflags.m4 b/m4/set_cflags_ldflags.m4
index 08f5c983cc..23706e256b 100644
--- a/m4/set_cflags_ldflags.m4
+++ b/m4/set_cflags_ldflags.m4
@@ -15,7 +15,7 @@ for ldflag in $APPEND_LIB
 do
     APPEND_LDFLAGS="$APPEND_LDFLAGS -L$ldflag"
 done
-if [ ! -z $EXTRA_PREFIX ]; then
+if test ! -z "$EXTRA_PREFIX" ; then
     CPPFLAGS="$CPPFLAGS -I$EXTRA_PREFIX/include"
     LDFLAGS="$LDFLAGS -L$EXTRA_PREFIX/lib"
 fi
--
generated by git-patchbot for /home/xen/git/xen.git#master