[PATCH v2 005/142] git-rebase.sh: use the $( ... ) construct for command substitution

The Git CodingGuidelines prefer the $( ... ) construct for command
substitution instead of using the back-quotes, or grave accents (`..`).

The backquoted form is the historical method for command substitution,
and is supported by POSIX. However, all but the simplest uses become
complicated quickly. In particular, embedded command substitutions
and/or the use of double quotes require careful escaping with the backslash
character. Because of this the POSIX shell adopted the $(…) feature from
the Korn shell.

The patch was generated by the simple script

for _f in $(find . -name "*.sh")
do
  sed -i 's@`\(.*\)`@$(\1)@g' ${_f}
done

Signed-off-by: Elia Pinto <redacted>
---
 git-rebase.sh |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/git-rebase.sh b/git-rebase.sh
index 5f6732b..a209ab9 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh

@@ -462,8 +462,8 @@ then
 else
 	if test -z "$onto"
 	then
-		empty_tree=`git hash-object -t tree /dev/null`
-		onto=`git commit-tree $empty_tree </dev/null`
+		empty_tree=$(git hash-object -t tree /dev/null)
+		onto=$(git commit-tree $empty_tree </dev/null)
 		squash_onto="$onto"
 	fi
 	unset upstream_name

@@ -521,10 +521,10 @@ case "$#" in
 	;;
 0)
 	# Do not need to switch branches, we are already on it.
-	if branch_name=`git symbolic-ref -q HEAD`
+	if branch_name=$(git symbolic-ref -q HEAD)
 	then
 		head_name=$branch_name
-		branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
+		branch_name=$(expr "z$branch_name" : 'zrefs/heads/\(.*\)')
 	else
 		head_name="detached HEAD"
 		branch_name=HEAD ;# detached

-- 
1.7.10.4