Fix unbound variable errors applying stash of secret file

The GIT_REFLOG_ACTION and THEIRS_LABEL environment variables are
normally available when doing a merge with git, but are undefined
when merging a stash.

This change and the prior one avoids the `unbound variable` error
when these variables are unset by defaulting to empty values, and
falling back to "theirs" as the in-merge description of incoming
changes from the stash.

Author: jmurty

CHANGELOG.md

@@ -22,6 +22,8 @@ The format is based on [Keep a Changelog][1], and this project adheres to
 - Compatibility fix for LibreSSL versions 3 (and above) especially for MacOS
   13 Ventura to more carefully apply a work-around required for OpenSSL 3+
   that isn't required for LibreSSL 3+ (#147 #133)
+- Fix errors applying a stash containing a secret file that needs to be merged
+  with staged changes to the same file (#150)
 
 ## [2.2.0] - 2022-07-09
 

transcrypt

@@ -264,7 +264,7 @@ git_merge() {
 	if [[ "${GIT_REFLOG_ACTION:-}" = "merge "* ]]; then
 		THEIRS_LABEL=$(echo "$GIT_REFLOG_ACTION" | awk '{print $2}')
 	fi
-	if [[ ! "$THEIRS_LABEL" ]]; then
+	if [[ ! "${THEIRS_LABEL:-}" ]]; then
 		THEIRS_LABEL="theirs"
 	fi
 	# Decrypt BASE $1, LOCAL $2, and REMOTE $3 versions of file being merged