diff --git a/data/helpers.d/backup b/data/helpers.d/backup
index 60e9fca94..e5186cb59 100644
--- a/data/helpers.d/backup
+++ b/data/helpers.d/backup
@@ -77,7 +77,8 @@ ynh_backup() {
     # Format correctly source and destination paths
     # ==============================================================================
     # Be sure the source path is not empty
-    [[ -e "${src_path}" ]] || {
+    if [ ! -e "$src_path" ]
+    then
         ynh_print_warn --message="Source path '${src_path}' does not exist"
         if [ "$not_mandatory" == "0" ]
         then
@@ -92,7 +93,7 @@ ynh_backup() {
         else
             return 0
         fi
-    }
+    fi
 
     # Transform the source path as an absolute path
     # If it's a dir remove the ending /
@@ -119,20 +120,23 @@ ynh_backup() {
             dest_path="${dest_path#$YNH_CWD/}"
 
             # Case where $2 is an absolute dir but doesn't begin with $YNH_CWD
-            [[ "${dest_path:0:1}" == "/" ]] \
-                && dest_path="${dest_path#/}"
+            if [[ "${dest_path:0:1}" == "/" ]]; then
+                dest_path="${dest_path#/}"
+            fi
         fi
 
         # Complete dest_path if ended by a /
-        [[ "${dest_path: -1}" == "/" ]] \
-            &&  dest_path="${dest_path}/$(basename $src_path)"
+        if [[ "${dest_path: -1}" == "/" ]]; then
+            dest_path="${dest_path}/$(basename $src_path)"
+        fi
     fi
 
     # Check if dest_path already exists in tmp archive
-    [[ ! -e "${dest_path}" ]] || {
+    if [[ -e "${dest_path}" ]]
+    then
         ynh_print_err --message="Destination path '${dest_path}' already exist"
         return 1
-    }
+    fi
 
     # Add the relative current working directory to the destination path
     local rel_dir="${YNH_CWD#$YNH_BACKUP_DIR}"
diff --git a/data/helpers.d/mysql b/data/helpers.d/mysql
index 62edd8822..7edc633b4 100644
--- a/data/helpers.d/mysql
+++ b/data/helpers.d/mysql
@@ -88,7 +88,9 @@ ynh_mysql_create_db() {
     if [[ $# -gt 1 ]]
     then
         sql+=" GRANT ALL PRIVILEGES ON ${db}.* TO '${2}'@'localhost'"
-        [[ -n ${3:-} ]] && sql+=" IDENTIFIED BY '${3}'"
+        if [[ -n ${3:-} ]]; then
+            sql+=" IDENTIFIED BY '${3}'"
+        fi
         sql+=" WITH GRANT OPTION;"
     fi
 
diff --git a/data/helpers.d/systemd b/data/helpers.d/systemd
index b6c4722af..871d6459d 100644
--- a/data/helpers.d/systemd
+++ b/data/helpers.d/systemd
@@ -32,10 +32,10 @@ ynh_add_systemd_config () {
 
     # To avoid a break by set -u, use a void substitution ${var:-}. If the variable is not set, it's simply set with an empty variable.
     # Substitute in a nginx config file only if the variable is not empty
-    if test -n "${final_path:-}"; then
+    if [ -n "${final_path:-}" ]; then
         ynh_replace_string --match_string="__FINALPATH__" --replace_string="$final_path" --target_file="$finalsystemdconf"
     fi
-    if test -n "${app:-}"; then
+    if [ -n "${app:-}" ]; then
         ynh_replace_string --match_string="__APP__" --replace_string="$app" --target_file="$finalsystemdconf"
     fi
     ynh_store_file_checksum --file="$finalsystemdconf"
@@ -123,10 +123,20 @@ ynh_systemd_action() {
         action="reload-or-restart"
     fi
 
-    systemctl $action $service_name \
-        || ( journalctl --no-pager --lines=$length -u $service_name >&2 \
-        ; test -e "$log_path" && echo "--" >&2 && tail --lines=$length "$log_path" >&2 \
-        ; false )
+    # If the service fails to perform the action
+    if ! systemctl $action $service_name
+    then
+        # Show syslog for this service
+        ynh_exec_err journalctl --no-pager --lines=$length --unit=$service_name
+        # If a log is specified for this service, show also the content of this log
+        if [ -e "$log_path" ]
+        then
+            ynh_print_err --message="--"
+            ynh_exec_err tail --lines=$length "$log_path"
+        fi
+        # Fail the app script, since the service failed.
+        false
+    fi
 
     # Start the timeout and try to find line_match
     if [[ -n "${line_match:-}" ]]
@@ -155,8 +165,12 @@ ynh_systemd_action() {
         then
             ynh_print_warn --message="The service $service_name didn't fully executed the action ${action} before the timeout."
             ynh_print_warn --message="Please find here an extract of the end of the log of the service $service_name:"
-            journalctl --no-pager --lines=$length -u $service_name >&2
-            test -e "$log_path" && echo "--" >&2 && tail --lines=$length "$log_path" >&2
+            ynh_exec_warn journalctl --no-pager --lines=$length --unit=$service_name
+            if [ -e "$log_path" ]
+            then
+                ynh_print_warn --message="--"
+                ynh_exec_warn tail --lines=$length "$log_path"
+            fi
         fi
         ynh_clean_check_starting
     fi
diff --git a/data/helpers.d/utils b/data/helpers.d/utils
index a991853e3..6b75426fc 100644
--- a/data/helpers.d/utils
+++ b/data/helpers.d/utils
@@ -188,13 +188,13 @@ ynh_setup_source () {
     fi
 
     # Apply patches
-    if (( $(find $YNH_CWD/../sources/patches/ -type f -name "${source_id}-*.patch" 2> /dev/null | wc -l) > "0" )); then
-        local old_dir=$(pwd)
-        (cd "$dest_dir" \
-            && for p in $YNH_CWD/../sources/patches/${source_id}-*.patch; do \
-                patch -p1 < $p; done) \
-            || ynh_die --message="Unable to apply patches"
-        cd $old_dir
+    if (( $(find $YNH_CWD/../sources/patches/ -type f -name "${source_id}-*.patch" 2> /dev/null | wc --lines) > "0" ))
+    then
+        (cd "$dest_dir"
+        for p in $YNH_CWD/../sources/patches/${source_id}-*.patch
+        do
+            patch --strip=1 < $p
+        done) || ynh_die --message="Unable to apply patches"
     fi
 
     # Add supplementary files