SAK-39957 If an imported comment cell is blank, clear any existing comment

Author: marktriggs

gradebookng/tool/src/java/org/sakaiproject/gradebookng/business/util/ImportGradesHelper.java

@@ -674,7 +674,10 @@ private static Status determineStatus(final ImportedColumn column, final Assignm
 
 					// has a value, could be NEW or an UPDATE. Preserve NEW if we already had it
 					if (status != Status.NEW) {
-						if (StringUtils.isNotBlank(importedComment) && !StringUtils.equals(importedComment, existingComment)) {
+						boolean importContainsNewComment = (StringUtils.isNotBlank(importedComment) && !StringUtils.equals(importedComment, existingComment));
+						boolean importClearsExistingComment = (StringUtils.isBlank(importedComment) && StringUtils.isNotBlank(existingComment));
+
+						if (importContainsNewComment || importClearsExistingComment) {
 							status = Status.UPDATE;
 							break;
 						}