Exit with error if new version is empty

scripts/download_clonezilla.sh

@@ -90,6 +90,33 @@ define_vars() {                                                 # {{{
 }
 # }}}
 
+is_var_empty() {                                                # {{{
+
+	## Return False by default
+	return_var_empty="1"
+	## Total number of variables to test
+	local_total_var="${#}"
+
+	loop_count_var_empty="0"
+
+	## While it remains a variable to test
+	while [ "${local_total_var}" -gt "${loop_count_var_empty}" ]; do
+		debug_message "is_var_empty − \
+Test var: ${1}."
+		### Test if this is empty and set return value to True
+		[ -z "${1}" ] && return_var_empty="0"
+
+		### Increase the number of tested variables
+		loop_count_var_empty=$((loop_count_var_empty+1))
+
+		### Shift to the next variable
+		shift
+	done
+
+	return "${return_var_empty}"
+
+}
+# }}}
 is_file_absent() {                                              # {{{
 
 	local_file_absent="${1}"
@@ -158,6 +185,12 @@ main() {                                                        # {{{
 	# Define all vars
 	define_vars
 
+	# If cz_version is empty {{{
+	# Exit with error
+	is_var_empty "${cz_version}" \
+		&& error_message "Clonezilla version variable is empty" 6
+	# }}}
+
 	# Create directories and config file
 	debug_message "Main − \
 Create ${CZ_INSTALLER_DIR} tree."

scripts/download_diag_tools.sh

@@ -110,6 +110,33 @@ define_vars() {                                                 # {{{
 }
 # }}}
 
+is_var_empty() {                                                # {{{
+
+	## Return False by default
+	return_var_empty="1"
+	## Total number of variables to test
+	local_total_var="${#}"
+
+	loop_count_var_empty="0"
+
+	## While it remains a variable to test
+	while [ "${local_total_var}" -gt "${loop_count_var_empty}" ]; do
+		debug_message "is_var_empty − \
+Test var: ${1}."
+		### Test if this is empty and set return value to True
+		[ -z "${1}" ] && return_var_empty="0"
+
+		### Increase the number of tested variables
+		loop_count_var_empty=$((loop_count_var_empty+1))
+
+		### Shift to the next variable
+		shift
+	done
+
+	return "${return_var_empty}"
+
+}
+# }}}
 is_file_absent() {                                              # {{{
 
 	local_file_absent="${1}"
@@ -178,6 +205,17 @@ main() {                                                        # {{{
 	# Define all vars
 	define_vars
 
+	# If memtest_version is empty {{{
+	# Exit with error
+	is_var_empty "${memtest_version}" \
+		&& error_message "Memtest version variable is empty" 6
+	# }}}
+	# If gparted_version is empty {{{
+	# Exit with error
+	is_var_empty "${gparted_version}" \
+		&& error_message "Memtest version variable is empty" 6
+	# }}}
+
 	# Create diagnostic tools directory and config file
 	mkdir --parents -- "${DIAG_INSTALLER_DIR}" \
 	|| error_message "Can't create ${DIAG_INSTALLER_DIR}/ directory." 1