swupdate-ab: improve error handling if mnt_point is empty

Depending on where the error occurs, mnt_point can be empty. If
this is the case, this error can happen:

Status: 4 message: ERROR util.c : read_lines_notify : 1166 : swupdate-ab.sh: Error: destination partition "/dev/mmcblk0p2" not found
Status: 4 message: ERROR util.c : read_lines_notify : 1166 : swupdate-ab.sh: Error 1 occurred
Status: 4 message: ERROR util.c : read_lines_notify : 1166 : BusyBox v1.36.1 () multi-call binary.
Status: 4 message: ERROR util.c : read_lines_notify : 1166 : Usage: grep [-HhnlLoqvsrRiwFE] [-m N] [-A|B|C N] { PATTERN | -e PATTERN... | -f FILE... } [FILE]...
Status: 2 message: [__run_cmd] : /tmp/scripts/swupdate-ab.sh preinst p2 command returned 1

Add check for valid mnt_point before trying to unmount.

diff --git a/recipes-support/swupdate/swupdate-ab/update.header.sh b/recipes-support/swupdate/swupdate-ab/update.header.sh
index 53df653..8eed7e4 100644 (file)
--- a/recipes-support/swupdate/swupdate-ab/update.header.sh
+++ b/recipes-support/swupdate/swupdate-ab/update.header.sh
@@ -26,10 +26,12 @@ catch()
 {
     if [ "$1" != "0" ]; then
         # Error handling goes here
-        echo "Error $1 occurred"
+        printf >&2 "$(basename ${0}): Error $1 occurred\n"
 
-        if mount | grep -q ${mnt_point}; then
-            unmount_destination_partition
+        if [ -n "${mnt_point}" ]; then
+            if mount | grep -q ${mnt_point}; then
+                unmount_destination_partition
+            fi
         fi
     fi
 }