Handle missing kernel .config better (bug #271528)

gen_configkernel.sh

@@ -29,7 +29,19 @@ config_kernel() {
 	determine_config_file
 	cd "${KERNEL_DIR}" || gen_die 'Could not switch to the kernel directory!'
 
-	isTrue "${CLEAN}" && cp "${KERNEL_DIR}/.config" "${KERNEL_DIR}/.config.bak" > /dev/null 2>&1
+	# Backup and replace kernel .config
+	if isTrue "${CLEAN}" || [ ! -f "${KERNEL_DIR}/.config" ]
+	then
+		print_info 1 "config: Using config from ${KERNEL_CONFIG}"
+		if [ -f "${KERNEL_DIR}/.config" ]
+		then
+			cp "${KERNEL_DIR}/.config" "${KERNEL_DIR}/.config.bak" \
+					|| gen_die "Could not backup kernel config (${KERNEL_DIR}/.config)"
+			print_info 1 '        Previous config backed up to .config.bak'
+		fi
+		cp "${KERNEL_CONFIG}" "${KERNEL_DIR}/.config" || gen_die 'Could not copy configuration file!'
+	fi
+
 	if isTrue ${MRPROPER}
 	then
 		print_info 1 'kernel: >> Running mrproper...'
@@ -39,12 +51,6 @@ config_kernel() {
 	# If we're not cleaning, then we don't want to try to overwrite the configs
 	# or we might remove configurations someone is trying to test.
 
-	if isTrue "${CLEAN}"
-	then
-		print_info 1 "config: Using config from ${KERNEL_CONFIG}"
-		print_info 1 '        Previous config backed up to .config.bak'
-		cp "${KERNEL_CONFIG}" "${KERNEL_DIR}/.config" || gen_die 'Could not copy configuration file!'
-	fi
 	if isTrue "${OLDCONFIG}"
 	then
 		print_info 1 '        >> Running oldconfig...'
@@ -55,7 +61,7 @@ config_kernel() {
 		print_info 1 'kernel: >> Cleaning...'
 		compile_generic clean kernel
 	else
-		print_info 1 "config: --no-clean is enabled; leaving the .config alone."
+		print_info 1 "config: --no-clean is enabled; not running 'make clean'."
 	fi
 	
 	if isTrue ${MENUCONFIG}