--- a/tools/lint/shellcheck.yml
+++ b/tools/lint/shellcheck.yml
@@ -1,12 +1,13 @@
 ---
 shellcheck:
     description: Shell script linter
     include:
         - taskcluster/docker/
+        - tools/update-packaging/
     exclude: []
     # 1090: https://github.com/koalaman/shellcheck/wiki/SC1090
     # 'Can't follow a non-constant source'
     extensions: ['sh']
     excludecodes: ['1090', '1091']
     type: external
     payload: shell:lint

--- a/tools/update-packaging/common.sh
+++ b/tools/update-packaging/common.sh
@@ -8,50 +8,48 @@
 # Author: Darin Fisher
 #
 
 # -----------------------------------------------------------------------------
 # By default just assume that these tools exist on our path
 MAR=${MAR:-mar}
 MBSDIFF=${MBSDIFF:-mbsdiff}
 if [[ -z "${MAR_OLD_FORMAT}" ]]; then
-  XZ=${XZ:-xz}
-  $XZ --version > /dev/null 2>&1
-  if [ $? -ne 0 ]; then
-    # If $XZ is not set and not found on the path then this is probably
-    # running on a windows buildbot. Some of the Windows build systems have
-    # xz.exe in topsrcdir/xz/. Look in the places this would be in both a
-    # mozilla-central and comm-central build.
-    XZ="$(dirname "$(dirname "$(dirname "$0")")")/xz/xz.exe"
-    $XZ --version > /dev/null 2>&1
-    if [ $? -ne 0 ]; then
-      XZ="$(dirname "$(dirname "$(dirname "$(dirname "$0")")")")/xz/xz.exe"
-      $XZ --version > /dev/null 2>&1
-      if [ $? -ne 0 ]; then
-        echo "xz was not found on this system!"
-        echo "exiting"
-        exit 1
-      fi
+  while read -r XZ
+  do
+    if ${XZ} --version > /dev/null 2>&1
+    then
+      break
     fi
+  done << EOM
+${XZ:-xz}
+$(dirname "$(dirname "$(dirname "$0")")")/xz/xz.exe
+$(dirname "$(dirname "$(dirname "$(dirname "$0")")")")/xz/xz.exe
+EOM
+
+  if [ -z "${XZ}" ]
+  then
+      echo "xz was not found on this system!"
+      echo "exiting"
+      exit 1
   fi
 else
   MAR_OLD_FORMAT=1
   BZIP2=${BZIP2:-bzip2}
 fi
 
 # -----------------------------------------------------------------------------
 # Helper routines
 
 notice() {
   echo "$*" 1>&2
 }
 
 get_file_size() {
-  info=($(ls -ln "$1"))
-  echo ${info[4]}
+  stat -f"%z" "$1"
 }
 
 copy_perm() {
   reference="$1"
   target="$2"
 
   if [ -x "$reference" ]; then
     chmod 0755 "$target"
@@ -66,163 +64,167 @@ make_add_instruction() {
   # The third param will be an empty string when a file add instruction is only
   # needed in the version 2 manifest. This only happens when the file has an
   # add-if-not instruction in the version 3 manifest. This is due to the
   # precomplete file prior to the version 3 manifest having a remove instruction
   # for this file so the file is removed before applying a complete update.
   filev3="$3"
 
   # Used to log to the console
-  if [ $4 ]; then
+  if [ "$4" ]; then
     forced=" (forced)"
   else
     forced=
   fi
 
-  is_extension=$(echo "$f" | grep -c 'distribution/extensions/.*/')
-  if [ $is_extension = "1" ]; then
+  if [[ "$f" =~ distribution/extensions/.*/ ]]
+  then
     # Use the subdirectory of the extensions folder as the file to test
     # before performing this add instruction.
     testdir=$(echo "$f" | sed 's/\(.*distribution\/extensions\/[^\/]*\)\/.*/\1/')
     notice "     add-if \"$testdir\" \"$f\""
-    echo "add-if \"$testdir\" \"$f\"" >> "$filev2"
-    if [ ! $filev3 = "" ]; then
-      echo "add-if \"$testdir\" \"$f\"" >> "$filev3"
+    printf 'add-if "%s" "%s"\n' "${testdir}" "${f}" >> "${filev2}"
+    if [ -n "${filev3}" ]; then
+      printf 'add-if "%s" "%s"\n' "${testdir}" "${f}" >> "${filev3}"
     fi
   else
     notice "        add \"$f\"$forced"
-    echo "add \"$f\"" >> "$filev2"
+    printf 'add "%s"\n' "${f}" >> "${filev2}"
     if [ ! "$filev3" = "" ]; then
-      echo "add \"$f\"" >> "$filev3"
+      printf 'add "%s"\n' "${f}" >> "${filev3}"
     fi
   fi
 }
 
 check_for_add_if_not_update() {
   add_if_not_file_chk="$1"
 
-  if [ `basename $add_if_not_file_chk` = "channel-prefs.js" -o \
-       `basename $add_if_not_file_chk` = "update-settings.ini" ]; then
-    ## "true" *giggle*
+  if [ "$(basename "$add_if_not_file_chk")" = "channel-prefs.js" ] || \
+     [ "$(basename "$add_if_not_file_chk")" = "update-settings.ini" ]
+  then
     return 0;
   fi
-  ## 'false'... because this is bash. Oh yay!
   return 1;
 }
 
 check_for_add_to_manifestv2() {
   add_if_not_file_chk="$1"
 
-  if [ `basename $add_if_not_file_chk` = "update-settings.ini" ]; then
-    ## "true" *giggle*
+  if [ "$(basename "$add_if_not_file_chk")" = "update-settings.ini" ]
+  then
     return 0;
   fi
-  ## 'false'... because this is bash. Oh yay!
   return 1;
 }
 
 make_add_if_not_instruction() {
   f="$1"
   filev3="$2"
 
   notice " add-if-not \"$f\" \"$f\""
-  echo "add-if-not \"$f\" \"$f\"" >> "$filev3"
+  printf 'add-if-not "%s" "%s"\n' "${f}" "${f}" >> "${filev3}"
 }
 
 make_patch_instruction() {
   f="$1"
   filev2="$2"
   filev3="$3"
 
-  is_extension=$(echo "$f" | grep -c 'distribution/extensions/.*/')
-  if [ $is_extension = "1" ]; then
+  if [[ "$f" =~ distribution/extensions/.*/ ]]
+  then
     # Use the subdirectory of the extensions folder as the file to test
     # before performing this add instruction.
     testdir=$(echo "$f" | sed 's/\(.*distribution\/extensions\/[^\/]*\)\/.*/\1/')
     notice "   patch-if \"$testdir\" \"$f.patch\" \"$f\""
-    echo "patch-if \"$testdir\" \"$f.patch\" \"$f\"" >> "$filev2"
-    echo "patch-if \"$testdir\" \"$f.patch\" \"$f\"" >> "$filev3"
+    printf 'patch-if "%s" "%s.patch" "%s"\n' "${testdir}" "${f}" "${f}" >> "${filev2}"
+    printf 'patch-if "%s" "%s.patch" "%s"\n' "${testdir}" "${f}" "${f}" >> "${filev3}"
   else
     notice "      patch \"$f.patch\" \"$f\""
-    echo "patch \"$f.patch\" \"$f\"" >> "$filev2"
-    echo "patch \"$f.patch\" \"$f\"" >> "$filev3"
+    printf 'patch "%s.patch" "%s"\n' "${f}" "${f}" >> "${filev2}"
+    printf 'patch "%s.patch" "%s"\n' "${f}" "${f}" >> "${filev3}"
   fi
 }
 
 append_remove_instructions() {
   dir="$1"
   filev2="$2"
   filev3="$3"
 
-  if [ -f "$dir/removed-files" ]; then
+  if [ -f "$dir/removed-files" ]
+  then
     listfile="$dir/removed-files"
-  elif [ -f "$dir/Contents/Resources/removed-files" ]; then
+  elif [ -f "$dir/Contents/Resources/removed-files" ]
+  then
     listfile="$dir/Contents/Resources/removed-files"
   fi
-  if [ -n "$listfile" ]; then
-    # Map spaces to pipes so that we correctly handle filenames with spaces.
-    files=($(cat "$listfile" | tr " " "|"  | sort -r))
-    num_files=${#files[*]}
-    for ((i=0; $i<$num_files; i=$i+1)); do
-      # Map pipes back to whitespace and remove carriage returns
-      f=$(echo ${files[$i]} | tr "|" " " | tr -d '\r')
-      # Trim whitespace
-      f=$(echo $f)
-      # Exclude blank lines.
-      if [ -n "$f" ]; then
-        # Exclude comments
-        if [ ! $(echo "$f" | grep -c '^#') = 1 ]; then
-          if [ $(echo "$f" | grep -c '\/$') = 1 ]; then
-            notice "      rmdir \"$f\""
-            echo "rmdir \"$f\"" >> "$filev2"
-            echo "rmdir \"$f\"" >> "$filev3"
-          elif [ $(echo "$f" | grep -c '\/\*$') = 1 ]; then
-            # Remove the *
-            f=$(echo "$f" | sed -e 's:\*$::')
-            notice "    rmrfdir \"$f\""
-            echo "rmrfdir \"$f\"" >> "$filev2"
-            echo "rmrfdir \"$f\"" >> "$filev3"
-          else
-            notice "     remove \"$f\""
-            echo "remove \"$f\"" >> "$filev2"
-            echo "remove \"$f\"" >> "$filev3"
-          fi
-        fi
-      fi
-    done
+  if [ -z "$listfile" ]; then
+    return
   fi
+
+  while read -r f
+  do
+    # skip blank lines
+    if [ -z "$f" ]
+    then
+      continue
+    fi
+    # skip comments
+    if [[ "$f" =~ ^\#.* ]]
+    then
+      continue
+    fi
+
+    if [[ "$f" =~ .*/$ ]]
+    then
+      notice "      rmdir \"$f\""
+      printf 'rmdir "%s"\n' "${f}" >> "${filev2}"
+      printf 'rmdir "%s"\n' "${f}" >> "${filev3}"
+    elif [[ "$f" =~ .*/\*$ ]]
+    then
+      # Remove the *
+      f=${f%\*}
+      notice "    rmrfdir \"$f\""
+      printf 'rmrfdir "%s"\n' "${f}" >> "${filev2}"
+      printf 'rmrfdir "%s"\n' "${f}" >> "${filev3}"
+    else
+      notice "     remove \"$f\""
+      printf 'remove "%s"\n' "${f}" >> "${filev2}"
+      printf 'remove "%s"\n' "${f}" >> "${filev3}"
+    fi
+  done <"$listfile"
 }
 
 # List all files in the current directory, stripping leading "./"
 # Pass a variable name and it will be filled as an array.
 list_files() {
   count=0
-
+  tmpfile="$(mktemp)"
   find . -type f \
     ! -name "update.manifest" \
     ! -name "updatev2.manifest" \
     ! -name "updatev3.manifest" \
     ! -name "temp-dirlist" \
     ! -name "temp-filelist" \
     | sed 's/\.\/\(.*\)/\1/' \
-    | sort -r > "temp-filelist"
-  while read file; do
+    | sort -r > "${tmpfile}"
+  while read -r file; do
     eval "${1}[$count]=\"$file\""
     (( count++ ))
-  done < "temp-filelist"
-  rm "temp-filelist"
+  done <"${tmpfile}"
+  rm -f "${tmpfile}"
 }
 
 # List all directories in the current directory, stripping leading "./"
 list_dirs() {
   count=0
+  tmpfile="$(mktemp)"
 
   find . -type d \
     ! -name "." \
     ! -name ".." \
     | sed 's/\.\/\(.*\)/\1/' \
-    | sort -r > "temp-dirlist"
-  while read dir; do
+    | sort -r > "${tmpfile}"
+  while read -r dir; do
     eval "${1}[$count]=\"$dir\""
     (( count++ ))
-  done < "temp-dirlist"
-  rm "temp-dirlist"
+  done <"${tmpfile}"
+  rm -f "${tmpfile}"
 }

--- a/tools/update-packaging/make_full_update.sh
+++ b/tools/update-packaging/make_full_update.sh
@@ -3,90 +3,90 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #
 # This tool generates full update packages for the update system.
 # Author: Darin Fisher
 #
 
-. $(dirname "$0")/common.sh
+# shellcheck disable=SC1090
+. "$(dirname "$0")/common.sh"
 
 # -----------------------------------------------------------------------------
 
 print_usage() {
-  notice "Usage: $(basename $0) [OPTIONS] ARCHIVE DIRECTORY"
+  notice "Usage: $(basename "$0") [OPTIONS] ARCHIVE DIRECTORY"
 }
 
 if [ $# = 0 ]; then
   print_usage
   exit 1
 fi
 
-if [ $1 = -h ]; then
+if [ "$1" = -h ]; then
   print_usage
   notice ""
   notice "The contents of DIRECTORY will be stored in ARCHIVE."
   notice ""
   notice "Options:"
   notice "  -h  show this help text"
   notice ""
   exit 1
 fi
 
 # -----------------------------------------------------------------------------
 
 archive="$1"
 targetdir="$2"
 # Prevent the workdir from being inside the targetdir so it isn't included in
 # the update mar.
-if [ $(echo "$targetdir" | grep -c '\/$') = 1 ]; then
+if [ "$(echo "$targetdir" | grep -c '\/$')" = 1 ]; then
   # Remove the /
-  targetdir=$(echo "$targetdir" | sed -e 's:\/$::')
+  targetdir=${targetdir%/}
 fi
 workdir="$targetdir.work"
 updatemanifestv2="$workdir/updatev2.manifest"
 updatemanifestv3="$workdir/updatev3.manifest"
 targetfiles="updatev2.manifest updatev3.manifest"
 
 mkdir -p "$workdir"
 
 # Generate a list of all files in the target directory.
-pushd "$targetdir"
+pushd "$targetdir" || exit 1
 if test $? -ne 0 ; then
   exit 1
 fi
 
 if [ ! -f "precomplete" ]; then
   if [ ! -f "Contents/Resources/precomplete" ]; then
     notice "precomplete file is missing!"
     exit 1
   fi
 fi
 
+declare -a files
 list_files files
 
-popd
+popd || exit 1
 
 # Add the type of update to the beginning of the update manifests.
-> "$updatemanifestv2"
-> "$updatemanifestv3"
+: > "$updatemanifestv2"
+: > "$updatemanifestv3"
 notice ""
 notice "Adding type instruction to update manifests"
 notice "       type complete"
 echo "type \"complete\"" >> "$updatemanifestv2"
 echo "type \"complete\"" >> "$updatemanifestv3"
 
 notice ""
 notice "Adding file add instructions to update manifests"
-num_files=${#files[*]}
 
-for ((i=0; $i<$num_files; i=$i+1)); do
-  f="${files[$i]}"
-
+for f in "${files[@]}"
+do
   if check_for_add_if_not_update "$f"; then
     make_add_if_not_instruction "$f" "$updatemanifestv3"
     if check_for_add_to_manifestv2 "$f"; then
       make_add_instruction "$f" "$updatemanifestv2" "" 1
     fi
   else
     make_add_instruction "$f" "$updatemanifestv2" "$updatemanifestv3"
   fi

--- a/tools/update-packaging/make_incremental_update.sh
+++ b/tools/update-packaging/make_incremental_update.sh
@@ -3,22 +3,23 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #
 # This tool generates incremental update packages for the update system.
 # Author: Darin Fisher
 #
 
-. $(dirname "$0")/common.sh
+# shellcheck disable=SC1090
+. "$(dirname "$0")/common.sh"
 
 # -----------------------------------------------------------------------------
 
 print_usage() {
-  notice "Usage: $(basename $0) [OPTIONS] ARCHIVE FROMDIR TODIR"
+  notice "Usage: $(basename "$0") [OPTIONS] ARCHIVE FROMDIR TODIR"
   notice ""
   notice "The differences between FROMDIR and TODIR will be stored in ARCHIVE."
   notice ""
   notice "Options:"
   notice "  -h  show this help text"
   notice "  -f  clobber this file in the installation"
   notice "      Must be a path to a file to clobber in the partial update."
   notice ""
@@ -26,58 +27,49 @@ print_usage() {
 
 check_for_forced_update() {
   force_list="$1"
   forced_file_chk="$2"
 
   local f
 
   if [ "$forced_file_chk" = "precomplete" ]; then
-    ## "true" *giggle*
     return 0;
   fi
 
   if [ "$forced_file_chk" = "Contents/Resources/precomplete" ]; then
-    ## "true" *giggle*
     return 0;
   fi
 
   if [ "$forced_file_chk" = "removed-files" ]; then
-    ## "true" *giggle*
     return 0;
   fi
 
   if [ "$forced_file_chk" = "Contents/Resources/removed-files" ]; then
-    ## "true" *giggle*
     return 0;
   fi
 
   if [ "$forced_file_chk" = "chrome.manifest" ]; then
-    ## "true" *giggle*
     return 0;
   fi
 
   if [ "$forced_file_chk" = "Contents/Resources/chrome.manifest" ]; then
-    ## "true" *giggle*
     return 0;
   fi
 
   if [ "${forced_file_chk##*.}" = "chk" ]; then
-    ## "true" *giggle*
     return 0;
   fi
 
   for f in $force_list; do
     #echo comparing $forced_file_chk to $f
     if [ "$forced_file_chk" = "$f" ]; then
-      ## "true" *giggle*
       return 0;
     fi
   done
-  ## 'false'... because this is bash. Oh yay!
   return 1;
 }
 
 if [ $# = 0 ]; then
   print_usage
   exit 1
 fi
 
@@ -92,102 +84,95 @@ do
       ;;
       ?) print_usage; exit 1
       ;;
    esac
 done
 
 # -----------------------------------------------------------------------------
 
-let arg_start=$OPTIND-1
+arg_start=$((OPTIND-1))
 shift $arg_start
 
 archive="$1"
 olddir="$2"
 newdir="$3"
 # Prevent the workdir from being inside the targetdir so it isn't included in
 # the update mar.
-if [ $(echo "$newdir" | grep -c '\/$') = 1 ]; then
-  # Remove the /
-  newdir=$(echo "$newdir" | sed -e 's:\/$::')
-fi
+
+# Remove the /
+newdir="${newdir%/}"
+
 workdir="$newdir.work"
 updatemanifestv2="$workdir/updatev2.manifest"
 updatemanifestv3="$workdir/updatev3.manifest"
 archivefiles="updatev2.manifest updatev3.manifest"
 
 mkdir -p "$workdir"
 
 # Generate a list of all files in the target directory.
-pushd "$olddir"
-if test $? -ne 0 ; then
+pushd "$olddir" || exit 1
+
+declare -a oldfiles
+list_files oldfiles
+declare -a olddirs
+list_dirs olddirs
+
+popd || exit 1
+
+pushd "$newdir" || exit 1
+
+if [ ! -f "precomplete" ] && [ ! -f "Contents/Resources/precomplete" ]
+then
+  notice "precomplete file is missing!"
   exit 1
 fi
 
-list_files oldfiles
-list_dirs olddirs
-
-popd
-
-pushd "$newdir"
-if test $? -ne 0 ; then
-  exit 1
-fi
-
-if [ ! -f "precomplete" ]; then
-  if [ ! -f "Contents/Resources/precomplete" ]; then
-    notice "precomplete file is missing!"
-    exit 1
-  fi
-fi
-
-list_dirs newdirs
+declare -a newfiles
 list_files newfiles
 
-popd
+popd || exit 1
 
 # Add the type of update to the beginning of the update manifests.
 notice ""
 notice "Adding type instruction to update manifests"
-> $updatemanifestv2
-> $updatemanifestv3
+: > "$updatemanifestv2"
+: > "$updatemanifestv3"
 notice "       type partial"
-echo "type \"partial\"" >> $updatemanifestv2
-echo "type \"partial\"" >> $updatemanifestv3
+echo 'type "partial"' >> "$updatemanifestv2"
+echo 'type "partial"' >> "$updatemanifestv3"
 
 notice ""
 notice "Adding file patch and add instructions to update manifests"
 
-num_oldfiles=${#oldfiles[*]}
-remove_array=
+declare -a remove_array
 num_removes=0
 
-for ((i=0; $i<$num_oldfiles; i=$i+1)); do
-  f="${oldfiles[$i]}"
-
+for f in "${oldfiles[@]}"
+do
   # If this file exists in the new directory as well, then check if it differs.
   if [ -f "$newdir/$f" ]; then
 
     if check_for_add_if_not_update "$f"; then
       # The full workdir may not exist yet, so create it if necessary.
-      mkdir -p `dirname "$workdir/$f"`
+      mkdir -p "$(dirname "$workdir/$f")"
       if [[ -n $MAR_OLD_FORMAT ]]; then
         $BZIP2 -cz9 "$newdir/$f" > "$workdir/$f"
       else
         $XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force --stdout "$newdir/$f" > "$workdir/$f"
       fi
       copy_perm "$newdir/$f" "$workdir/$f"
       make_add_if_not_instruction "$f" "$updatemanifestv3"
       archivefiles="$archivefiles \"$f\""
       continue 1
     fi
 
     if check_for_forced_update "$requested_forced_updates" "$f"; then
       # The full workdir may not exist yet, so create it if necessary.
-      mkdir -p `dirname "$workdir/$f"`
+      mkdir -p "$(dirname "$workdir/$f")"
       if [[ -n $MAR_OLD_FORMAT ]]; then
         $BZIP2 -cz9 "$newdir/$f" > "$workdir/$f"
       else
         $XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force --stdout "$newdir/$f" > "$workdir/$f"
       fi
       copy_perm "$newdir/$f" "$workdir/$f"
       make_add_instruction "$f" "$updatemanifestv2" "$updatemanifestv3" 1
       archivefiles="$archivefiles \"$f\""
@@ -207,61 +192,51 @@ for ((i=0; $i<$num_oldfiles; i=$i+1)); d
       # An example of MBSDIFF_HOOK env variable could look like this:
       # export MBSDIFF_HOOK="myscript.sh -A https://funsize/api -c /home/user"
       # where myscript.sh has the following usage:
       # myscript.sh -A SERVER-URL [-c LOCAL-CACHE-DIR-PATH] [-g] [-u] \
       #   PATH-FROM-URL PATH-TO-URL PATH-PATCH SERVER-URL
       #
       # Note: patches are bzipped or xz stashed in funsize to gain more speed
 
-      # if service is not enabled then default to old behavior
-      if [ -z "$MBSDIFF_HOOK" ]; then
-        $MBSDIFF "$olddir/$f" "$newdir/$f" "$workdir/$f.patch"
-        if [[ -n $MAR_OLD_FORMAT ]]; then
-          $BZIP2 -z9 "$workdir/$f.patch"
-        else
-          $XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force "$workdir/$f.patch"
-        fi
+      if [[ -n $MAR_OLD_FORMAT ]]
+      then
+        COMPRESS="$BZIP2 -z9"
+        EXT=".bz2"
+        STDOUT="-c"
       else
-        # if service enabled then check patch existence for retrieval
-        if [[ -n $MAR_OLD_FORMAT ]]; then
-          if $MBSDIFF_HOOK -g "$olddir/$f" "$newdir/$f" "$workdir/$f.patch.bz2"; then
-            notice "file \"$f\" found in funsize, diffing skipped"
-          else
-            # if not found already - compute it and cache it for future use
-            $MBSDIFF "$olddir/$f" "$newdir/$f" "$workdir/$f.patch"
-            $BZIP2 -z9 "$workdir/$f.patch"
-            $MBSDIFF_HOOK -u "$olddir/$f" "$newdir/$f" "$workdir/$f.patch.bz2"
-          fi
+        COMPRESS="$XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force"
+        EXT=".xz"
+        STDOUT="--stdout"
+      fi
+
+      if [ -z "$MBSDIFF_HOOK" ]
+      then
+        $MBSDIFF "$olddir/$f" "$newdir/$f" "$workdir/$f.patch"
+        $COMPRESS "$workdir/$f.patch"
+      else
+        if $MBSDIFF_HOOK -g "$olddir/$f" "$newdir/$f" "$workdir/$f.patch${EXT}"
+        then
+          notice "file \"$f\" found in funsize, diffing skipped"
         else
-          if $MBSDIFF_HOOK -g "$olddir/$f" "$newdir/$f" "$workdir/$f.patch.xz"; then
-            notice "file \"$f\" found in funsize, diffing skipped"
-          else
-            # if not found already - compute it and cache it for future use
-            $MBSDIFF "$olddir/$f" "$newdir/$f" "$workdir/$f.patch"
-            $XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force "$workdir/$f.patch"
-            $MBSDIFF_HOOK -u "$olddir/$f" "$newdir/$f" "$workdir/$f.patch.xz"
-          fi
+          # if not found already - compute it and cache it for future use
+          $MBSDIFF "$olddir/$f" "$newdir/$f" "$workdir/$f.patch"
+          $COMPRESS "$workdir/$f.patch"
+          $MBSDIFF_HOOK -u "$olddir/$f" "$newdir/$f" "$workdir/$f.patch${EXT}"
         fi
       fi
-      if [[ -n $MAR_OLD_FORMAT ]]; then
-        $BZIP2 -cz9 "$newdir/$f" > "$workdir/$f"
-      else
-        $XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force --stdout "$newdir/$f" > "$workdir/$f"
-      fi
+      $COMPRESS $STDOUT "$newdir/$f" > "$workdir/$f"
+
       copy_perm "$newdir/$f" "$workdir/$f"
-      if [[ -n $MAR_OLD_FORMAT ]]; then
-        patchfile="$workdir/$f.patch.bz2"
-      else
-        patchfile="$workdir/$f.patch.xz"
-      fi
+      patchfile="$workdir/$f.patch${EXT}"
+
       patchsize=$(get_file_size "$patchfile")
       fullsize=$(get_file_size "$workdir/$f")
 
-      if [ $patchsize -lt $fullsize ]; then
+      if [ "$patchsize" -lt "$fullsize" ]; then
         make_patch_instruction "$f" "$updatemanifestv2" "$updatemanifestv3"
         mv -f "$patchfile" "$workdir/$f.patch"
         rm -f "$workdir/$f"
         archivefiles="$archivefiles \"$f.patch\""
       else
         make_add_instruction "$f" "$updatemanifestv2" "$updatemanifestv3"
         rm -f "$patchfile"
         archivefiles="$archivefiles \"$f\""
@@ -273,28 +248,26 @@ for ((i=0; $i<$num_oldfiles; i=$i+1)); d
     remove_array[$num_removes]=$f
     (( num_removes++ ))
   fi
 done
 
 # Newly added files
 notice ""
 notice "Adding file add instructions to update manifests"
-num_newfiles=${#newfiles[*]}
 
-for ((i=0; $i<$num_newfiles; i=$i+1)); do
-  f="${newfiles[$i]}"
-
-  # If we've already tested this file, then skip it
-  for ((j=0; $j<$num_oldfiles; j=$j+1)); do
-    if [ "$f" = "${oldfiles[j]}" ]; then
+for f in "${newfiles[@]}"
+do
+  for j in "${oldfiles[@]}"
+  do
+    if [ "$f" = "$j" ]
+    then
       continue 2
     fi
   done
-
   dir=$(dirname "$workdir/$f")
   mkdir -p "$dir"
 
   if [[ -n $MAR_OLD_FORMAT ]]; then
     $BZIP2 -cz9 "$newdir/$f" > "$workdir/$f"
   else
     $XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force --stdout "$newdir/$f" > "$workdir/$f"
   fi
@@ -307,39 +280,38 @@ for ((i=0; $i<$num_newfiles; i=$i+1)); d
   fi
 
 
   archivefiles="$archivefiles \"$f\""
 done
 
 notice ""
 notice "Adding file remove instructions to update manifests"
-for ((i=0; $i<$num_removes; i=$i+1)); do
-  f="${remove_array[$i]}"
+for f in "${remove_array[@]}"
+do
   notice "     remove \"$f\""
-  echo "remove \"$f\"" >> $updatemanifestv2
-  echo "remove \"$f\"" >> $updatemanifestv3
+  echo "remove \"$f\"" >> "$updatemanifestv2"
+  echo "remove \"$f\"" >> "$updatemanifestv3"
 done
 
 # Add remove instructions for any dead files.
 notice ""
 notice "Adding file and directory remove instructions from file 'removed-files'"
 append_remove_instructions "$newdir" "$updatemanifestv2" "$updatemanifestv3"
 
 notice ""
 notice "Adding directory remove instructions for directories that no longer exist"
-num_olddirs=${#olddirs[*]}
 
-for ((i=0; $i<$num_olddirs; i=$i+1)); do
-  f="${olddirs[$i]}"
+for f in "${olddirs[@]}"
+do
   # If this dir doesn't exist in the new directory remove it.
   if [ ! -d "$newdir/$f" ]; then
     notice "      rmdir $f/"
-    echo "rmdir \"$f/\"" >> $updatemanifestv2
-    echo "rmdir \"$f/\"" >> $updatemanifestv3
+    echo "rmdir \"$f/\"" >> "$updatemanifestv2"
+    echo "rmdir \"$f/\"" >> "$updatemanifestv3"
   fi
 done
 
 if [[ -n $MAR_OLD_FORMAT ]]; then
   $BZIP2 -z9 "$updatemanifestv2" && mv -f "$updatemanifestv2.bz2" "$updatemanifestv2"
   $BZIP2 -z9 "$updatemanifestv3" && mv -f "$updatemanifestv3.bz2" "$updatemanifestv3"
 else
   $XZ --compress --x86 --lzma2 --format=xz --check=crc64 --force "$updatemanifestv2" && mv -f "$updatemanifestv2.xz" "$updatemanifestv2"

--- a/tools/update-packaging/test/buildrefmars.sh
+++ b/tools/update-packaging/test/buildrefmars.sh
@@ -3,25 +3,25 @@
 
 if [ -f "ref.mar" ]; then
   rm "ref.mar"
 fi
 if [ -f "ref-mac.mar" ]; then
   rm "ref-mac.mar"
 fi
 
- ../make_incremental_update.sh ref.mar `pwd`/from `pwd`/to
- ../make_incremental_update.sh ref-mac.mar `pwd`/from-mac `pwd`/to-mac
+ ../make_incremental_update.sh ref.mar "$(pwd)/from" "$(pwd)/to"
+ ../make_incremental_update.sh ref-mac.mar "$(pwd)/from-mac" "$(pwd)/to-mac"
 
 if [ -f "product-1.0.lang.platform.complete.mar" ]; then
   rm "product-1.0.lang.platform.complete.mar"
 fi
 if [ -f "product-2.0.lang.platform.complete.mar" ]; then
   rm "product-2.0.lang.platform.complete.mar"
 fi
 if [ -f "product-2.0.lang.mac.complete.mar" ]; then
   rm "product-2.0.lang.mac.complete.mar"
 fi
 
-./make_full_update.sh product-1.0.lang.platform.complete.mar "`pwd`/from"
-./make_full_update.sh product-2.0.lang.platform.complete.mar "`pwd`/to"
-./make_full_update.sh product-1.0.lang.mac.complete.mar "`pwd`/from-mac"
-./make_full_update.sh product-2.0.lang.mac.complete.mar "`pwd`/to-mac"
+./make_full_update.sh product-1.0.lang.platform.complete.mar "$(pwd)/from"
+./make_full_update.sh product-2.0.lang.platform.complete.mar "$(pwd)/to"
+./make_full_update.sh product-1.0.lang.mac.complete.mar "$(pwd)/from-mac"
+./make_full_update.sh product-2.0.lang.mac.complete.mar "$(pwd)/to-mac"

--- a/tools/update-packaging/test/catmanifest.sh
+++ b/tools/update-packaging/test/catmanifest.sh
@@ -1,14 +1,14 @@
 #!/bin/bash
 # helper tool for testing.  Cats the manifest out of a mar file
 
 mar="$1"
 workdir="/tmp/catmanifest"
 
 rm -rf "$workdir"
 mkdir -p "$workdir"
-cp "$1" "$workdir"
-cd "$workdir"
-mar -x "$1"
+cp "$mar" "$workdir"
+cd "$workdir" || exit 1
+mar -x "$mar"
 mv updatev2.manifest updatev2.manifest.xz
 xz -d updatev2.manifest.xz
 cat updatev2.manifest

--- a/tools/update-packaging/test/common.sh
+++ b/tools/update-packaging/test/common.sh
@@ -2,34 +2,54 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #
 # Code shared by update packaging scripts.
 # Author: Darin Fisher
 #
-# In here to use the local common.sh to allow the full mars to have unfiltered files
 
 # -----------------------------------------------------------------------------
 # By default just assume that these tools exist on our path
 MAR=${MAR:-mar}
-XZ=${XZ:-xz}
 MBSDIFF=${MBSDIFF:-mbsdiff}
+if [[ -z "${MAR_OLD_FORMAT}" ]]; then
+  while read -r XZ
+  do
+    if ${XZ} --version > /dev/null 2>&1
+    then
+      break
+    fi
+  done << EOM
+${XZ:-xz}
+$(dirname "$(dirname "$(dirname "$0")")")/xz/xz.exe
+$(dirname "$(dirname "$(dirname "$(dirname "$0")")")")/xz/xz.exe
+EOM
+
+  if [ -z "${XZ}" ]
+  then
+      echo "xz was not found on this system!"
+      echo "exiting"
+      exit 1
+  fi
+else
+  MAR_OLD_FORMAT=1
+  BZIP2=${BZIP2:-bzip2}
+fi
 
 # -----------------------------------------------------------------------------
 # Helper routines
 
 notice() {
   echo "$*" 1>&2
 }
 
 get_file_size() {
-  info=($(ls -ln "$1"))
-  echo ${info[4]}
+  stat -f"%z" "$1"
 }
 
 copy_perm() {
   reference="$1"
   target="$2"
 
   if [ -x "$reference" ]; then
     chmod 0755 "$target"
@@ -44,159 +64,167 @@ make_add_instruction() {
   # The third param will be an empty string when a file add instruction is only
   # needed in the version 2 manifest. This only happens when the file has an
   # add-if-not instruction in the version 3 manifest. This is due to the
   # precomplete file prior to the version 3 manifest having a remove instruction
   # for this file so the file is removed before applying a complete update.
   filev3="$3"
 
   # Used to log to the console
-  if [ $4 ]; then
+  if [ "$4" ]; then
     forced=" (forced)"
   else
     forced=
   fi
 
-  is_extension=$(echo "$f" | grep -c 'distribution/extensions/.*/')
-  if [ $is_extension = "1" ]; then
+  if [[ "$f" =~ distribution/extensions/.*/ ]]
+  then
     # Use the subdirectory of the extensions folder as the file to test
     # before performing this add instruction.
     testdir=$(echo "$f" | sed 's/\(.*distribution\/extensions\/[^\/]*\)\/.*/\1/')
     notice "     add-if \"$testdir\" \"$f\""
-    echo "add-if \"$testdir\" \"$f\"" >> $filev2
-    if [ ! $filev3 = "" ]; then
-      echo "add-if \"$testdir\" \"$f\"" >> $filev3
+    printf 'add-if "%s" "%s"\n' "${testdir}" "${f}" >> "${filev2}"
+    if [ -n "${filev3}" ]; then
+      printf 'add-if "%s" "%s"\n' "${testdir}" "${f}" >> "${filev3}"
     fi
   else
     notice "        add \"$f\"$forced"
-    echo "add \"$f\"" >> $filev2
-    if [ ! $filev3 = "" ]; then
-      echo "add \"$f\"" >> $filev3
+    printf 'add "%s"\n' "${f}" >> "${filev2}"
+    if [ ! "$filev3" = "" ]; then
+      printf 'add "%s"\n' "${f}" >> "${filev3}"
     fi
   fi
 }
 
 check_for_add_if_not_update() {
   add_if_not_file_chk="$1"
 
-  if [ `basename $add_if_not_file_chk` = "channel-prefs.js" -o \
-       `basename $add_if_not_file_chk` = "update-settings.ini" ]; then
-    ## "true" *giggle*
+  if [ "$(basename "$add_if_not_file_chk")" = "channel-prefs.js" ] || \
+     [ "$(basename "$add_if_not_file_chk")" = "update-settings.ini" ]
+  then
     return 0;
   fi
-  ## 'false'... because this is bash. Oh yay!
   return 1;
 }
 
 check_for_add_to_manifestv2() {
   add_if_not_file_chk="$1"
 
-  if [ `basename $add_if_not_file_chk` = "update-settings.ini" ]; then
-    ## "true" *giggle*
+  if [ "$(basename "$add_if_not_file_chk")" = "update-settings.ini" ]
+  then
     return 0;
   fi
-  ## 'false'... because this is bash. Oh yay!
   return 1;
 }
 
 make_add_if_not_instruction() {
   f="$1"
   filev3="$2"
 
   notice " add-if-not \"$f\" \"$f\""
-  echo "add-if-not \"$f\" \"$f\"" >> $filev3
+  printf 'add-if-not "%s" "%s"\n' "${f}" "${f}" >> "${filev3}"
 }
 
 make_patch_instruction() {
   f="$1"
   filev2="$2"
   filev3="$3"
 
-  is_extension=$(echo "$f" | grep -c 'distribution/extensions/.*/')
-  if [ $is_extension = "1" ]; then
+  if [[ "$f" =~ distribution/extensions/.*/ ]]
+  then
     # Use the subdirectory of the extensions folder as the file to test
     # before performing this add instruction.
     testdir=$(echo "$f" | sed 's/\(.*distribution\/extensions\/[^\/]*\)\/.*/\1/')
     notice "   patch-if \"$testdir\" \"$f.patch\" \"$f\""
-    echo "patch-if \"$testdir\" \"$f.patch\" \"$f\"" >> $filev2
-    echo "patch-if \"$testdir\" \"$f.patch\" \"$f\"" >> $filev3
+    printf 'patch-if "%s" "%s.patch" "%s"\n' "${testdir}" "${f}" "${f}" >> "${filev2}"
+    printf 'patch-if "%s" "%s.patch" "%s"\n' "${testdir}" "${f}" "${f}" >> "${filev3}"
   else
     notice "      patch \"$f.patch\" \"$f\""
-    echo "patch \"$f.patch\" \"$f\"" >> $filev2
-    echo "patch \"$f.patch\" \"$f\"" >> $filev3
+    printf 'patch "%s.patch" "%s"\n' "${f}" "${f}" >> "${filev2}"
+    printf 'patch "%s.patch" "%s"\n' "${f}" "${f}" >> "${filev3}"
   fi
 }
 
 append_remove_instructions() {
   dir="$1"
   filev2="$2"
   filev3="$3"
 
-  if [ -f "$dir/removed-files" ]; then
+  if [ -f "$dir/removed-files" ]
+  then
     listfile="$dir/removed-files"
-  elif [ -f "$dir/Contents/Resources/removed-files" ]; then
+  elif [ -f "$dir/Contents/Resources/removed-files" ]
+  then
     listfile="$dir/Contents/Resources/removed-files"
   fi
-  if [ -n "$listfile" ]; then
-    # Map spaces to pipes so that we correctly handle filenames with spaces.
-    files=($(cat "$listfile" | tr " " "|"  | sort -r))
-    num_files=${#files[*]}
-    for ((i=0; $i<$num_files; i=$i+1)); do
-      # Map pipes back to whitespace and remove carriage returns
-      f=$(echo ${files[$i]} | tr "|" " " | tr -d '\r')
-      # Trim whitespace
-      f=$(echo $f)
-      # Exclude blank lines.
-      if [ -n "$f" ]; then
-        # Exclude comments
-        if [ ! $(echo "$f" | grep -c '^#') = 1 ]; then
-          if [ $(echo "$f" | grep -c '\/$') = 1 ]; then
-            notice "      rmdir \"$f\""
-            echo "rmdir \"$f\"" >> $filev2
-            echo "rmdir \"$f\"" >> $filev3
-          elif [ $(echo "$f" | grep -c '\/\*$') = 1 ]; then
-            # Remove the *
-            f=$(echo "$f" | sed -e 's:\*$::')
-            notice "    rmrfdir \"$f\""
-            echo "rmrfdir \"$f\"" >> $filev2
-            echo "rmrfdir \"$f\"" >> $filev3
-          else
-            notice "     remove \"$f\""
-            echo "remove \"$f\"" >> $filev2
-            echo "remove \"$f\"" >> $filev3
-          fi
-        fi
-      fi
-    done
+  if [ -z "$listfile" ]; then
+    return
   fi
+
+  while read -r f
+  do
+    # skip blank lines
+    if [ -z "$f" ]
+    then
+      continue
+    fi
+    # skip comments
+    if [[ "$f" =~ ^\#.* ]]
+    then
+      continue
+    fi
+
+    if [[ "$f" =~ .*/$ ]]
+    then
+      notice "      rmdir \"$f\""
+      printf 'rmdir "%s"\n' "${f}" >> "${filev2}"
+      printf 'rmdir "%s"\n' "${f}" >> "${filev3}"
+    elif [[ "$f" =~ .*/\*$ ]]
+    then
+      # Remove the *
+      f=${f%\*}
+      notice "    rmrfdir \"$f\""
+      printf 'rmrfdir "%s"\n' "${f}" >> "${filev2}"
+      printf 'rmrfdir "%s"\n' "${f}" >> "${filev3}"
+    else
+      notice "     remove \"$f\""
+      printf 'remove "%s"\n' "${f}" >> "${filev2}"
+      printf 'remove "%s"\n' "${f}" >> "${filev3}"
+    fi
+  done <"$listfile"
 }
 
 # List all files in the current directory, stripping leading "./"
 # Pass a variable name and it will be filled as an array.
 list_files() {
   count=0
-
-  # Removed the exclusion cases here to allow for generation of testing mars
+  tmpfile="$(mktemp)"
   find . -type f \
+    ! -name "update.manifest" \
+    ! -name "updatev2.manifest" \
+    ! -name "updatev3.manifest" \
+    ! -name "temp-dirlist" \
+    ! -name "temp-filelist" \
     | sed 's/\.\/\(.*\)/\1/' \
-    | sort -r > "$workdir/temp-filelist"
-  while read file; do
+    | sort -r > "${tmpfile}"
+  while read -r file; do
     eval "${1}[$count]=\"$file\""
     (( count++ ))
-  done < "$workdir/temp-filelist"
-  rm "$workdir/temp-filelist"
+  done <"${tmpfile}"
+  rm -f "${tmpfile}"
 }
 
 # List all directories in the current directory, stripping leading "./"
 list_dirs() {
   count=0
+  tmpfile="$(mktemp)"
 
   find . -type d \
     ! -name "." \
     ! -name ".." \
     | sed 's/\.\/\(.*\)/\1/' \
-    | sort -r > "$workdir/temp-dirlist"
-  while read dir; do
+    | sort -r > "${tmpfile}"
+  while read -r dir; do
     eval "${1}[$count]=\"$dir\""
     (( count++ ))
-  done < "$workdir/temp-dirlist"
-  rm "$workdir/temp-dirlist"
+  done <"${tmpfile}"
+  rm -f "${tmpfile}"
 }

--- a/tools/update-packaging/test/diffmar.sh
+++ b/tools/update-packaging/test/diffmar.sh
@@ -7,45 +7,45 @@ testDir="$3"
 workdir="/tmp/diffmar/$testDir"
 fromdir="$workdir/0"
 todir="$workdir/1"
 
 # On Windows, creation time can be off by a second or more between the files in
 # the fromdir and todir due to them being extracted synchronously so use
 # time-style and exclude seconds from the creation time.
 lsargs="-algR"
-unamestr=`uname`
+unamestr=$(uname)
 if [ ! "$unamestr" = 'Darwin' ]; then
-  unamestr=`uname -o`
-  if [ "$unamestr" = 'Msys' -o "$unamestr" = "Cygwin" ]; then
+  unamestr=$(uname -o)
+  if [ "$unamestr" = 'Msys' ] || [ "$unamestr" = "Cygwin" ]; then
      lsargs="-algR --time-style=+%Y-%m-%d-%H:%M"
   fi
 fi
 
 rm -rf "$workdir"
 mkdir -p "$fromdir"
 mkdir -p "$todir"
 
 cp "$1" "$fromdir"
 cp "$2" "$todir"
 
-cd "$fromdir"
-mar -x "$1"
-rm "$1"
+cd "$fromdir" || exit 1
+mar -x "$marA"
+rm "$marA"
 mv updatev2.manifest updatev2.manifest.xz
 xz -d updatev2.manifest.xz
 mv updatev3.manifest updatev3.manifest.xz
 xz -d updatev3.manifest.xz
-ls $lsargs > files.txt
+ls "$lsargs" > files.txt
 
-cd "$todir"
-mar -x "$2"
-rm "$2"
+cd "$todir" || exit 1
+mar -x "$marB"
+rm "$marB"
 mv updatev2.manifest updatev2.manifest.xz
 xz -d updatev2.manifest.xz
 mv updatev3.manifest updatev3.manifest.xz
 xz -d updatev3.manifest.xz
-ls $lsargs > files.txt
+ls "$lsargs" > files.txt
 
 echo "diffing $fromdir and $todir"
 echo "on linux shell sort and python sort return different results"
 echo "which can cause differences in the manifest files"
 diff -ru "$fromdir" "$todir"

--- a/tools/update-packaging/test/make_full_update.sh
+++ b/tools/update-packaging/test/make_full_update.sh
@@ -4,90 +4,90 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #
 # This tool generates full update packages for the update system.
 # Author: Darin Fisher
 #
 # In here to use the local common.sh to allow the full mars to have unfiltered files
 
-. $(dirname "$0")/common.sh
+# shellcheck disable=SC1090
+. "$(dirname "$0")/common.sh"
 
 # -----------------------------------------------------------------------------
 
 print_usage() {
-  notice "Usage: $(basename $0) [OPTIONS] ARCHIVE DIRECTORY"
+  notice "Usage: $(basename "$0") [OPTIONS] ARCHIVE DIRECTORY"
 }
 
 if [ $# = 0 ]; then
   print_usage
   exit 1
 fi
 
-if [ $1 = -h ]; then
+if [ "$1" = -h ]; then
   print_usage
   notice ""
   notice "The contents of DIRECTORY will be stored in ARCHIVE."
   notice ""
   notice "Options:"
   notice "  -h  show this help text"
   notice ""
   exit 1
 fi
 
 # -----------------------------------------------------------------------------
 
 archive="$1"
 targetdir="$2"
 # Prevent the workdir from being inside the targetdir so it isn't included in
 # the update mar.
-if [ $(echo "$targetdir" | grep -c '\/$') = 1 ]; then
+if [ "$(echo "$targetdir" | grep -c '\/$')" = 1 ]; then
   # Remove the /
-  targetdir=$(echo "$targetdir" | sed -e 's:\/$::')
+  targetdir=${targetdir%/}
 fi
 workdir="$targetdir.work"
 updatemanifestv2="$workdir/updatev2.manifest"
 updatemanifestv3="$workdir/updatev3.manifest"
 targetfiles="updatev2.manifest updatev3.manifest"
 
 mkdir -p "$workdir"
 
 # Generate a list of all files in the target directory.
-pushd "$targetdir"
+pushd "$targetdir" || exit 1
 if test $? -ne 0 ; then
   exit 1
 fi
 
 if [ ! -f "precomplete" ]; then
   if [ ! -f "Contents/Resources/precomplete" ]; then
     notice "precomplete file is missing!"
     exit 1
   fi
 fi
 
+declare -a files
 list_files files
 
-popd
+popd || exit 1
 
 # Add the type of update to the beginning of the update manifests.
-> $updatemanifestv2
-> $updatemanifestv3
+: > "$updatemanifestv2"
+: > "$updatemanifestv3"
 notice ""
 notice "Adding type instruction to update manifests"
 notice "       type complete"
-echo "type \"complete\"" >> $updatemanifestv2
-echo "type \"complete\"" >> $updatemanifestv3
+echo "type \"complete\"" >> "$updatemanifestv2"
+echo "type \"complete\"" >> "$updatemanifestv3"
 
 notice ""
 notice "Adding file add instructions to update manifests"
-num_files=${#files[*]}
 
-for ((i=0; $i<$num_files; i=$i+1)); do
-  f="${files[$i]}"
-
+for f in "${files[@]}"
+do
   if check_for_add_if_not_update "$f"; then
     make_add_if_not_instruction "$f" "$updatemanifestv3"
     if check_for_add_to_manifestv2 "$f"; then
       make_add_instruction "$f" "$updatemanifestv2" "" 1
     fi
   else
     make_add_instruction "$f" "$updatemanifestv2" "$updatemanifestv3"
   fi