Modernize git-move-commits

* Replace `` with $()
* Put bare variables in ""
* Disable bad shellcheck warnings

Author: unixorn

bin/git-move-commits

@@ -8,42 +8,45 @@
 # if correct-branch does exist, it merges the commits
 set -e
 
-if [ $1 ]
+if [ "$1" ]
 then
+    # shellcheck disable=SC2046,SC2143
     if [ ! $(echo "$1" | grep -E "^[0-9]+$") ]
     then
         echo "$1 is not a number."
         echo "Usage: git move-commits <num-commits> <correct-branch>";
         exit 1;
     else
         # The count is 0 based, so to move the last 1 commit, we need HEAD~0
-        NUM_COMMITS=$1
+        NUM_COMMITS="$1"
         ((NUM_COMMITS--))
         echo "num commits $NUM_COMMITS"
     fi
 else
     echo "Usage: git move-commits <num-commits> <correct-branch>";
     exit 1;
 fi
-if [ -z $2 ]
+if [ -z "$2" ]
 then
     echo "Usage: git move-commits <num-commits> <correct-branch>";
     exit 1;
 else
-    BRANCH=$2
+    BRANCH="$2"
 fi
 
-CURRENT_BRANCH=`git branch | grep '*' | perl -e '<STDIN> =~ /^..(.+)$/;print $1'`
+# shellcheck disable=SC2063
+CURRENT_BRANCH=$(git branch | grep '*' | perl -e '<STDIN> =~ /^..(.+)$/;print $1')
 
 # If the branch already exists, we have to merge it with the current branch
-if ! [ -z `git branch -a | grep $BRANCH` ]
+# shellcheck disable=SC2143,SC2046
+if ! [ -z $(git branch -a | grep "$BRANCH") ]
 then
     echo "$BRANCH already exists. Switching to it and merging $CURRENT_BRANCH"
-    git checkout $BRANCH
-    git merge $CURRENT_BRANCH
+    git checkout "$BRANCH"
+    git merge "$CURRENT_BRANCH"
 else
     echo "Creating $BRANCH"
-    git branch $BRANCH
+    git branch "$BRANCH"
 fi
-git reset --hard $CURRENT_BRANCH~$NUM_COMMITS
-git checkout $BRANCH
+git reset --hard "$CURRENT_BRANCH~$NUM_COMMITS"
+git checkout "$BRANCH"