GEODE-6059: Get ahold of origin/develop in StressNewTests

This job was failing because concourse was no longer creating an origin
remote in the git repo.

Also, changing the script to fail if there are issues with some of
commands we are executing in $().

ci/scripts/repeat-new-tests.sh

@@ -29,15 +29,20 @@ SCRIPTDIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
 
 function changes_for_path() {
   cd geode
-  local path="$1" # only expand once in the line below
-  git diff --name-only HEAD $(git merge-base HEAD origin/develop) -- $path
+  local path; path="$1" # only expand once in the line below
+  local merge_base; merge_base=$(git merge-base HEAD origin/develop) || exit $?
+  git diff --name-only HEAD $merge_base -- $path
 }
 
-UNIT_TEST_CHANGES=$(changes_for_path '*/src/test/java')
-INTEGRATION_TEST_CHANGES=$(changes_for_path '*/src/integrationTest/java')
-DISTRIBUTED_TEST_CHANGES=$(changes_for_path '*/src/distributedTest/java')
-ACCEPTANCE_TEST_CHANGES=$(changes_for_path '*/src/acceptanceTest/java')
-UPGRADE_TEST_CHANGES=$(changes_for_path '*/src/upgradeTest/java')
+cd geode
+git fetch https://github.com/apache/geode.git develop:origin/develop
+cd ..
+
+UNIT_TEST_CHANGES=$(changes_for_path '*/src/test/java') || exit $?
+INTEGRATION_TEST_CHANGES=$(changes_for_path '*/src/integrationTest/java') || exit $?
+DISTRIBUTED_TEST_CHANGES=$(changes_for_path '*/src/distributedTest/java') || exit $?
+ACCEPTANCE_TEST_CHANGES=$(changes_for_path '*/src/acceptanceTest/java') || exit $?
+UPGRADE_TEST_CHANGES=$(changes_for_path '*/src/upgradeTest/java') || exit $?
 
 CHANGED_FILES_ARRAY=( $UNIT_TEST_CHANGES $INTEGRATION_TEST_CHANGES $DISTRIBUTED_TEST_CHANGES $ACCEPTANCE_TEST_CHANGES $UPGRADE_TEST_CHANGES )
 NUM_CHANGED_FILES=${#CHANGED_FILES_ARRAY[@]}