do not write empty diff lines

Author: jdaugherty

etc/bin/verify-reproducible.sh

@@ -90,7 +90,13 @@ cd "${DOWNLOAD_LOCATION}/${PROJECT_NAME}/etc/bin/results"
 echo "Checking for differences in checksums"
 # diff -u CHECKSUMS second.txt
 DIFF_RESULTS=$(comm -3 <(sort ../../../CHECKSUMS) <(sort second.txt) | cut -d' ' -f1 | sed 's/^[[:space:]]*//;s/[[:space:]]*$//' | grep -v '^$' | uniq | sort)
-echo "$DIFF_RESULTS" > diff.txt
+echo "${DIFF_RESULTS}" > diff.txt
+
+if [ -n "${DIFF_RESULTS}" ]; then
+  echo "${DIFF_RESULTS}" > diff.txt
+else
+  > diff.txt  # Empty the file explicitly
+fi
 
 if [ -s diff.txt ]; then
   echo "Differences were found, diffing jar files ..."
@@ -104,7 +110,7 @@ if [ -s diff.txt ]; then
   fi
 
   while IFS= read -r jar_file; do
-      echo "Checking jar ${jar_file}..."
+      echo "Checking jar '${jar_file}'..."
 
       echo "Extracting ${jar_file}"
       "${SCRIPT_DIR}/extract-build-artifact.sh" "${jar_file}" "${DOWNLOAD_LOCATION}/${PROJECT_NAME}/etc/bin/results"