[PATCH 08/10] git-mergetool.sh: don't use the -a or -b option with the test command

[Elia Pinto <gitter.spiros@gmail.com>]

Even though POSIX.1 lists -a/-o as options to "test", they are
marked "Obsolescent XSI". Scripts using these expressions
should be converted  as follow:

test "$1" -a "$2"

should be written as:

test "$1" && test "$2"

Likewise

test "$1" -o "$2"

should be written as:

test "$1"  test "$2"

But note that, in test, -a has higher precedence than -o while
"&&" and "||" have equal precedence in the shell.

The reason for this is that the precedence rules were never well
specified, and this made many sane-looking uses of "test -a/-o" problematic.

For example, if $x is "=", these work according to POSIX (it's not
portable, but in practice it's okay):

   $ test -z "$x"
   $ test -z "$x" && test a = b

but this doesn't

   $ test -z "$x" -a a = b
   bash: test: too many arguments

because it groups "test -n = -a" and is left with "a = b".

Similarly, if $x is "-f", these

   $ test "$x"
   $ test "$x" || test c = d

correctly adds an implicit "-n", but this fails:

   $ test "$x" -o c = d
   bash: test: too many arguments

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
---
Inspired from this discussion http://permalink.gmane.org/gmane.comp.version-control.git/137056

 git-mergetool.sh |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/git-mergetool.sh b/git-mergetool.sh
index 332528f..88e853f 100755
--- a/git-mergetool.sh
+++ b/git-mergetool.sh
@@ -205,7 +205,7 @@ checkout_staged_file () {
 		"$(git checkout-index --temp --stage="$1" "$2" 2>/dev/null)" \
 		: '\([^	]*\)	')
 
-	if test $? -eq 0 -a -n "$tmpfile"
+	if test $? -eq 0 && test -n "$tmpfile"
 	then
 		mv -- "$(git rev-parse --show-cdup)$tmpfile" "$3"
 	else
@@ -256,7 +256,7 @@ merge_file () {
 	checkout_staged_file 2 "$MERGED" "$LOCAL"
 	checkout_staged_file 3 "$MERGED" "$REMOTE"
 
-	if test -z "$local_mode" -o -z "$remote_mode"
+	if test -z "$local_mode" || test -z "$remote_mode"
 	then
 		echo "Deleted merge conflict for '$MERGED':"
 		describe_file "$local_mode" "local" "$LOCAL"
-- 
1.7.10.4