build: Fix Shellcheck for get_source_date_epoch.sh

If a `cd` to `TOPDIR` fails the script should quit.

Also unify `try_mtime` function by storing it in a variable.

Signed-off-by: Paul Spooren <mail@aparcar.org>

diff --git a/scripts/get_source_date_epoch.sh b/scripts/get_source_date_epoch.sh
index 84ba4454543982716cc7f488840975ae832da104..8a41eebae7cd86aa50251ae2e7fdad4f393849d6 100755 (executable)
--- a/scripts/get_source_date_epoch.sh
+++ b/scripts/get_source_date_epoch.sh
@@ -1,7 +1,10 @@
 #!/usr/bin/env bash
 export LANG=C
 export LC_ALL=C
-[ -n "$TOPDIR" ] && cd $TOPDIR
+
+if [ -n "$TOPDIR" ]; then
+       cd "$TOPDIR" || exit 1
+fi
 
 try_version() {
        [ -f version.date ] || return 1
@@ -22,7 +25,7 @@ try_hg() {
 }
 
 try_mtime() {
-       perl -e 'print((stat $ARGV[0])[9])' "$0"
+       SOURCE_DATE_EPOCH=$(perl -e 'print((stat $ARGV[0])[9])' "$0")
        [ -n "$SOURCE_DATE_EPOCH" ]
 }