fix incorrect limit specification

Author: Paurikova2

dspace-api/src/main/java/org/dspace/app/reportdiff/ReportDiff.java

@@ -123,7 +123,9 @@ public void setup() throws ParseException {
         if (commandLine.hasOption('d')) {
             showDates = true;
             try {
-                limit = Long.parseLong(commandLine.getOptionValue("l"));
+                if (commandLine.hasOption("l")) {
+                    limit = Long.parseLong(commandLine.getOptionValue("l"));
+                }
             } catch (NumberFormatException e) {
                 handler.logError("Invalid value for -l. Must be a valid number.");
                 return;

dspace-api/src/main/java/org/dspace/app/reportdiff/ReportDiffScriptConfiguration.java

@@ -43,9 +43,10 @@ public Options getOptions() {
                             "otherwise perform default checks).", HealthReport.getNumberOfChecks() - 1));
             options.getOption("c").setType(String.class);
 
-            options.addOption("d", "dates", false,
-                    "Limit the number of report entries to this value. " +
-                    "If not specified, all entries are shown.");
+            options.addOption("d", "dates", false, "Show all report dates");
+
+            options.addOption("l", "limit", true,
+                    "Limit the number of entries (use only with -d). If omitted, all entries are shown.");
             options.getOption("l").setType(String.class);
 
             options.addOption("f", "from", true,"Report from specific date [YYYY-MM-DD HH:mm:ss.SSS].");